Envy was once considered to be one of the seven deadly sins before it became one of the most admired virtues under its new name, ‘social justice’.
Thomas Sowell
We’ve recently received a long-awaited (and we feared long-forgotten) order of two-handed Ootsukinomi paring chisels from our blacksmith. This post is a simple show and tell.
Your humble servant has scribbled about this tool in this article in our series about the varieties of Japanese chisels
Ootsukino, pronounced oh/tsuki/noh/mee, are large, long-handled paring chisels, the equivalent to the “slick” in the US woodworking tradition, a standard tool for timber framing. It is a rare chisel nowadays, and difficult to make.
This chisel is never struck with a hammer, but is pushed two-handed to pare surfaces and joints in wood to final dimensions. The long handle provides much greater angular control and precision than a standard paring chisel, while the ability to grasp it firmly in two hands makes it possible to effectively employ the greater power of one’s back and legs.
We also carry Mr. Usui’s Sukemaru-brand ootsukinomi, but after looking for a less-expensive option for our Beloved Customers, we ordered these from our Nagamitsu blacksmith over five years ago. Soon after placing the order we despaired of them ever being completed due to the difficulty of forging and shaping them in his advanced years, and did not want to pressure him. But we were surprised to learn recently, indeed after he had retired, that he had actually made significant progress on nine 2-piece sets, lacking only sharpening and handles, and so arranged for them to be completed. At long last they have been delivered.
Yes, this variety of chisel can be procured individually, and Mr. Usui of Sukemaru fame has been kind enough to fill many special orders to meet specific requirements of our Beloved Customer. But the standard way to purchase these in Japan is a 2-piece set, one chisel in 42~54mm blade width and the other in 24mm. We had these forged in the most common 48mm and 24mm boxed sets.
The overall length of both chisels is approximately 640mm (25-13/16″) with a 140mm (5-1/2″) long blade, 160mm (6 -19/64″) neck, and a 340mm (13-25/64″) handle made of an attractive grade of dark-red Japanese red oak. Both chisels have a standard, nicely-formed single ura with the hardened steel lamination properly wrapped up the blade’s sides for the extra toughness and rigidity essential to this tool.
A triple-ura on the 48mm chisel is a useful feature, and we have had Mr. Usui forge his chisels with this detail, but it would have added quite a bit to the cost and so is not available in this more economical brand.
The 48mm chisel is used for paring wider joint surfaces, the cheeks of tenons, and the interior side walls of mortises. It’s the standard mentori beveled-side design seen in our mentori oiirenomi, hantatakinomi and atsunomi.
The 24mm chisel is forged in the shinogi style with a more triangular cross-section to provide clearance for the blade in tight places to pare the many dovetail joints used to attach beams, purlins and bottom-plate (土台) timbers, as well as the end walls of the many 24mm mortises commonly found in traditional timber framing work.
These are not mass-produced tools but hand-forged in Japan from beginning to end by a highly-experienced blacksmith in his one-man smithy using Hitachi Metal’s Yasugi Shirogami No.1 high-carbon steel (White Label No.1 steel), famous for its superior sharpness, ease of sharpening, and sharpness retention performance for the cutting layer, forge-laminated to a softer low-carbon steel body and neck for toughness, typical of all our Nagamitsu-brand products.
These are nicely shaped and finished, top-quality, serious chisels for serious work, but are not suited to everyone. While joiners that make large doors and panels often have a set in their workshop, most cabinetmakers and furniture makers will seldom need such large chisels. But they are one of those tools that when you need them, nothing else will do. Indeed they are indispensable for cutting precise joints in large timbers and joinery, even when those joints are hogged-out using electrical equipment.
At this reduced price, We only have a few sets looking for new masters who will feed them lots of yummy wood, so if you are interested, please contact us using the form below.
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If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may every spoonful of burgundy cherry ice cream I ever eat taste like dirty truck tires.
5 responses to “New Ootsukinomi Paring Chisels”
Gary
Very nice, Stan. I have a couple of similarly sized ootsukinomi. Besides large joinery, I find that picking one up and waving it around is useful for chasing people out of the shop. It gets their attention.
I have a question about sharpening these. I know that it is easier to remove the handle for sharpening the blade. But after a few rounds of this the handles have become too loose. I have added paper shims inside the mortise for the tang, but that seems a short term solution. Is there a better long term solution, or should I just continue to add shims?
Thanks for your comment, Gary! I have never waved an ootsukinomi at, or used one to chase away, people, politicians or even pixies (descending order of humanity), but it sounds like a fun time was had by all. Please send link to video! (ツ) An ootsukinomi with a loose handle is extremely irritating, and if it becomes loose enough for the blade to separate from the handle on it’s own at an importune time that pervert Murphy may have a wonderful time dancing naked in puddles of red sticky stuff (sorry, no video). So while I don’t recommend routinely removing the handle after the initial sharpening, I do recommend using a honing jig to help maintain the proper bevel angle on the stones. Most people use a large block of hardwood cut at an angle and inlet to fit the chisel’s face for stability. When the wood becomes worn and the angle skewampus it can be refreshed with a thin angle-cut on a table saw, or maybe a pass or two on a jointer. I suppose the commercially-available jigs like the Lie-Nielson widget (perhaps with jaw extensions?) would work too and last longer, but whatever method used, it requires more physical effort and concentration than a shorter chisel does. Looking forward to the video! Stan
Thanks, Stan. I have a little sharpening widget that fits the blades but the long handle makes using it awkwardly unbalanced. I’ll go with a shop made hardwood fixture. And I’ll work on that video.
You’re right of course about how awkward and over-balanced the handle makes the process. Two options for the block. The first is moving the block/chisel on the stationary stone, and the second is to clamp the chisel/block down and move the stone over the blade’s bevel. The latter takes gear and time to setup, but perhaps yields better results with less risk. 2 drachma.
To your humble servant from another humble servant. Let’s not argue our spiritual merits! I enclose a couple of photos of a chisel I sadly only use occasionally. I’m too ignorant to identify its origins but it feels good in the hand when working or not. You might enjoy! Yours Bruce Milburn (convictions in darkness)
This is how your humble servant often feels at the end of the day. I need my chisels, I need my planes!
To achieve great things, two things are needed: a plan and not quite enough time.
Leonard Bernstein
Does Gentle Reader ever feel tired, restless, or achy after a difficult experience? Do these symptoms ever progress to insomnia, headache, neck pain, backache, chest pain or even (heaven forfend, I need a fire extinguisher) untimely spontaneous human combustion? And do any of these symptoms persist even after the pressures that precipitated them are gone? If so, you may be a human, perhaps even one of those with a brain and a soul connected to your body.
In this article, your most humble and obedient servant will, as Tim the Toolman Taylor often did, dare to diverge just a step or two from the beaten path of tool talk to consider how tools and woodworking may help us mitigate the dangerous stress most modern humans experience daily. So hi ho neighbor, let’s have a conversation over the fence.
A Tale of Stupidity
I promise you nothing is as chaotic as it seems. Nothing is worth diminishing your health. Nothing is worth poisoning yourself into stress, anxiety, and fear.”
Steve Maraboli
Allow me to begin with a true story, one of stupidity and toxic stress, just another fun day at the office.
Many years ago when the world was bubbling with promise, my head was fuzzier, my beard was darker and my waist was slimmer I was employed by a mid-sized Midwest construction company doing a design/ build factory for a Japanese precision parts manufacturer. Besides the construction of the factory expansion, the work included installing foundations for carburizing ovens used to create a hard skin on the steel parts they manufactured. I was tasked with marking out a concrete slab for core-drilling a series of pier foundations to support these ovens.
Everything went well, my layout drawing was approved, the slab was cored and piers were cast on-time. But when the equipment supplier’s salesman came to inspect the foundations he informed my boss they were spaced incorrectly. A disaster!
BTW, I was never told why my layout was wrong, but once the ovens arrived it was as obvious as the bill on a duck’s face that the manufacturer’s drawings didn’t match. In any case, at the time I was certain the foundations would need to be reworked, delaying installation of the ovens, and consequently the Owner’s production start, so I was sick with embarrassment at probably having delayed the project, and felt obligated to repay my employer the cost of remediating my apparent mistake. So between personal shame, the fear of potential schedule delays, and the thought of paying thousands of dollars out of my own pocket to make things right I was seriously stressed for about a week. Headaches, stomach aches and chest pains ensued forthwith.
My boss was a steady guy named Jim who heard out my profound apology while squinting at me like Blondie frequently did at Tuco the Rat, then snorted and called me an “ijit.”
Jim explained that if everyone who worked on a construction project were to be held personally financially responsible for minor unintentional mistakes, no one would do anything. And even if they were held responsible for their screwups, the construction company would then be obligated to pay them for everything they did right as a percentage of the project’s profits. And that wasn’t the arrangement.
Although Jim was gruff, even insulting, the results of his impromptu jobsite trailer therapy session were undeniable, providing me with necessary perspective, quickly dissolving the emotional stress that was crushing me, even relieving the physical symptoms I was suffering. And all without a couch! We all need someone like Jim.
When the crew that came to install the carburizing ovens entirely ignored the footings we had installed, but bolted steel “I ” beams to the slab instead, and then mounted the ovens on them I was shocked, even a little angry! They explained that’s how they always installed their equipment. And yes, all my self-recrimination and stress had been silly.
No doubt many Gentle Readers have learned similar lessons, but there’s a quote I’m fond of by Winston Churchill, the Prime Minister of England during WWII, a former soldier and fearless leader who bravely persevered as bombs and missiles rained down around him, the nation’s cowardly bureaucrats and politicians hid like rats in rubbish piles, civilian women and children were being murdered, and his nation was about to be invaded by a brutal enemy, to be apropos to most (but not all) stressful situations:
When I look back on all these worries, I remember the story of the old man who said on his deathbed that he had had a lot trouble in his life, most of which had never happened.
Winston S. Churchill
An iconic photo by Yousuf Karsh of Winston Churchill taken at the Hotel Château Laurier in Ottawa, Canada. Known as The Roaring Lion, it was stolen from the hotel’s Reading Room sometime after 2019, but it still has wide circulation as the image on the Bank of England’s £5 note. The story goes that Churchill did not want to be photographed, but permitted Karsh a single shot. To make the photograph more interesting, Karsh suddenly plucked Churchill’s ever-present lit cigar from his lips just before triggering the shutter prompting the glowering visage.
Herding Cats
Since those halcyon days my philosophy towards life and work has changed.
I once vainly believed I could control the people around me, or at least those I was responsible for, but with experience came the realization that attempting to control people is like pushing cats towards a goal with a small broom while demanding they knit sweaters along the way. The truth is that I have never been in control, that I can never successfully make anyone do anything, and that whenever I try to, all semblance of goodwill and cooperation is lost as everyone scatters and stress levels skyrocket.
One can never successfully “herd” cats, but at best only “lead” them (and sometimes even people) to go where you want them to go, or to do what you want them to do, with fish in hand, an even tone of voice and frequent ear rubbing, if you know what I mean.
While I don’t push people nowadays, I frequently have Clients, mostly inexperienced, egotistical, mid-management types who don’t have a clue but are frantic to climb the corporate ladder, consequences be damned, who expect such counter-productive foolishness of me on their employer’s behalf. Without appearing to refuse or contradict, of course, I always try to find other solutions, but when this is not possible and the Client stubbornly insists on Marxist measures, I separate myself from such projects because I know they will not only fail, but will yield unpleasant consequences for everybody involved, including tons of shame and crushing stress for me.
Don’t get me wrong, construction projects involve coordinating the efforts of a lot people, and sometimes stern measures are necessary, but nowadays while I still plan, lead, encourage, monitor, track and report progress, remind, sound alarms, send warnings, chide, reward, and even contractually penalize when necessary, I don’t push.
So here’s your unworthy servant’s current philosophy about life and stress in a nutshell:
Thoroughly understand your goals, objectives and responsibilities, plan how to accomplish them, be diligent in achieving them, and never blame others for your mistakes;
Without exception, everyone makes mistakes, constantly, so be as kind and understanding as reasonably possible. If you’re lucky, they might just return the favor, but even if they don’t, it will help to decrease stress levels all around. They’re just cats after all;
Don’t accept responsibility for anything for which you are not truly responsible;
Although senior executives in both the private and public sectors frequently secure their high pay and lofty station by abusing the goodwill of others, no matter how cleverly or coercively they present it, don’t allow anyone to foist either their responsibilities, or their mistakes, off onto you (unless you agree to it in advance and they pay you oodles of money for the resulting stress);
As taught by those Great Philosophers Lord Buddha of India and Red Green of Possum Lodge, always remember that life is suffering, all the time, and accept that Murphy will carnally poke you with his pointy purple pecker often and painfully, so don’t expect an easy time, and prepare Vaseline and bandages accordingly.
One last philosophical concept that I have found useful. In the West there’s the saying that goes “water off a duck’s back,” meaning nothing bothers you. In Japan they have a more colorful saying, one that many small boys have enacted, that goes “piss in a frog’s face.” To the duck it’s just another wet day in a wet place. To the frog, it’s just a warm shower. Since killing stress originates in the mind, the expectations of the duck and the frog are worth emulating. Seriously.
I believe that internalizing the 5 points listed above, perhaps urinating on frogs 𓆏 occasionally, and employing small remedies frequently rather than making big corrections too late, can minimize the need for Dr. Alonzo’s Pretty Purple Pills, those dreadfully unfashionable and scratchy canvas jackets with straps and buckles that chafe the crotch something fierce, and/or heart surgery.
Setting amphibian abuse, chest incisions and uncomfortable fashion aside for now, let us next consider one such small remedy.
Stress Reduction Measures
The criminal pharmaceutical companies and their well-paid “scientists” (aka “shills”) in the medical profession will happily sell you heaping pallets of pills to cure what ails you, but honest doctors frequently recommend less profitable, but no doubt more effective measures, including exercise, more sleep, vacations, music, reading, spending time with friends and family (even though they are frequently a cause of high stress), and hobbies. Some of these may work for you. I’ll touch on hobbies more below.
Many people like to imbibe a drop of grog at times to relieve accumulated stress. This is certainly the case here in Japan where people generally love demon rum but become inebriated easily due to an enzyme deficiency. But as someone who is frequently forced to spend time in the company of drinkers in business situations, I’ve concluded adult beverages don’t actually relieve stress but only make the drinker forget his problems for a few minutes as they worsen, turn him into a useless fool for a few hours, and destroy his liver forever. And don’t forget the injuries, traffic deaths, fights, jail time, divorce, poverty, suicides and murders cork-pulling always produces. Such an uplifting beverage.
One less-dangerous stress-relieving activity I can attest to is meditation, as in spending time alone in a quiet setting, without distractions, pondering simple questions internally without seeking actual answers. No, you don’t need to be a navel-gazing monk or smelly swami to do it, but you do need privacy and quiet, conditions often difficult to secure at home, especially since, regardless of her age, the female of the human species congenitally cannot tolerate the sight of a man being content while doing nothing, and will demand (probably in a cute manner) that he get busy following her orders. Thus it has always been.
But there’s another form of meditation your humble servant has found to reliably relieve stress, performed not in a hidden Shaolin temple or in a secluded grove, but still in a private, if perhaps dusty, environment.
The Holy Workshop
A beautiful 54mm Otsukinomi Paring Chisel by Nora.
Although I once worked wood professionally, it’s only my hobby now. But I find it that, when done correctly, even meditatively, it can be highly effective at relieving stress. To do it correctly, however, a simple workshop is necessary, one without email, telephones or other distractions.
Big or small, light or dark, warm or cold, the design doesn’t matter so long as it has a door, even if it’s an imaginary one like that of the renowned radio News Director and anchorman Les Nessman (5 time winner of the coveted Buckey News Hawk Award, donchano). Once I close this door, no one but me is allowed to enter its sacred precincts or fiddle with the sanity retention implements (tools) housed therein. And that includes bench dogs and cats. But for it to be a serene, meditative, healing space, She Who Must be Obeyed and “The Spawn” must be ruthlessly conditioned to quiver at the very thought of removing my tools, and dread the consequences of chucking junk into or storing stuff in the holy workshop.
When I am in my workshop, I accept no demands to do this or do that. I don’t respond to email or the telephone, unannounced visitors ringing the doorbell, calls to dinner, much less demands to take out the garbage. It’s not that the holy workshop makes me rude and/or unresponsive, it’s simply that these distractions are lower priority than my health for a short time, and the restorative balm must be allowed to soak in, you see.
In this private space I work on my projects, usually simple woodworking or tool maintenance, using the woods I love in the company of the undemanding, sharp friends that reside, play dice and drink beer in the evenings in my toolchest. No schedules. No one to criticize or complain, no one to seek approval or payment from, and no one to please but myself. And while the fruits of my time here mostly go to others, in this bubble environment I only make what I want to make, when I want to make it, using the materials I want to use and tools that willingly link my mind and soul to the wood I am shaping.
But lo, one more thing is essential to the effectiveness of the holy workshop: When people ask me what I make in there, I always answer “wood shavings and sawdust,” for you see almost any other answer invites prying questions and ultimately stirs up invasions by curious people with too much time on their hands who will invariably request woodworking-related “favors,” responding to which will induce more stress into my ragged life. Oh, and when children ask me what I plan to give them for birthdays or Christmas, I pretend to sort through my tattered memory and then respond in a serious tone: “Do you prefer wood shavings or sawdust?”
In past years, this workshop has been a piece of old carpet laid for a few hours on a concrete slab in front of a dingy apartment for my shorty sawhorses and atedai to cavort upon. At other times, it has been a reed mat spread under quaking aspen or pine trees in a mountain glade. Most often it has been half or all of a garage with a workbench. Lately it has been a spare bedroom on the second floor of a small single-family house in Tokyo. Whatever shape it takes or amenities it may have, my workshop is for just me, my wood, and my tools.
Conclusion
Although it’s hardly worth the effort, perhaps Gentle Reader now understands the method to my madness when I call my beautiful, faithful, hand-forged tools “sanity retention implements.” I am convinced the time we spend together has, like water from a duck’s back, shed much deadly stress from my life, making my little workshop and simple handtools cheaper than therapy, tastier than Dr. Alonzo’s Pretty Purple Pills, and certainly more pleasant than heart surgery. I no longer use my tools to feed my family, but I’m convinced they “cure what ails me.” Cheap at twice the price, say I!
Let’s conclude this merry tale of mental illness with a final quote about Winston that Gentle Reader may find inspirational.
He was one of the finest orators of all time. And some of the phrases he used still resonate with us today, such as “Finest hour,” “Never surrender,’ and of course, “We shall fight them bitches.”
Philomena Cunk para-quoting Winston Churchill
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Master carpenter Rokuza in Olde Edo with his plane and gennou hammer in hand, thinking about his lady instead of work. Some things never change.
To learn more about and to peruse our tools, please click the “Pricelist” link here or at the top of the page. To ask questions, please the “Contact Us” form located immediately below. You won’t be ignored.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google or fascist facebook and so won’t sell, share, or profitably “misplace” your information. If I lie may frogs pee in my face.
“The true mystery of the world is the visible, not the invisible.”
Oscar Wilde
In this post we will dig into a few important nitty gritty points about sharpening stones everyone needs to know. Perhaps Beloved Customer already knows all these points, but please ready your shovel because there may be at least one buried surprise.
A Wood Shavings-Eye View
When seen under high-magnification, the surface of a sharpening stone looks like millions of densely-packed stones embedded in a flat field. The smaller the stones, the finer the grit.
As the blade is pushed and pulled over these stones, they scratch and tear metal from the blade’s surface leaving behind scratches corresponding to the size of these small stones. This violence needs to continue until the blade’s ura and bevel form a clean intersection of two planes.
A view of a blade sharpened with 1200 grit diamond plate showing the furrows left by individual pieces of grit
Seen under high-magnification, the cutting edge is jagged where these furrow-like scratches terminate at the cutting edge. To some degree, it may even look like a serrated sawblade. Some blades, like kitchen knives and swords, are used in a slicing motion to cut soft materials like meat and vegetables and enemy arms, and their performance benefits from a serrated cutting edge more than a highly-polished edge, and so do not need to be highly polished on fine-grit sharpening stones.
Plane and chisel blades, however, are used to cut wood, a material typically harder than foodstuffs, mostly in a straight-on approach, not in a slicing motion. In this situation, a rough, serrated cutting edge is weaker than a highly polished edge because the jagged edges are projecting out into space like the teeth of a handsaw blade, and are relatively unsupported and more easily damaged than a highly-polished blade with smaller, more uniform scratches terminating more cleanly at the cutting edge.
Therefore, in order to produce a sharp durable blade, we must make the microscopic cutting edge smoother and more uniform by using progressively finer grit stones to produce shallower and narrower scratches, and a thin, uniform cutting edge.
But how fine is fine enough? There is a curious phenomenon related to friction that is applicable to cutting edges, and is useful to understand.
The Friction Paradox
Imagine a cube of heavy, polished stone with its downward flat face resting on the level, flat surface of a larger slab of similar stone. Let’s say it takes some specific measure of force pushing horizontally on the top stone cube to overcome the static force of friction between the two stone surfaces in order to get the cube moving.
If we gradually increase the degree of polish between the two contact faces and measure the force required to start the top cube moving at each progressively higher level of polish, we will find the force decreases with each increment of increased polish, at least for a time. This is at least partially because the irregularities between the two surfaces (asperities) do not interlock as deeply when the surfaces become more polished.
However, at some point, more polishing brings the surfaces of the two stones into such intimate contact that the molecular attraction between them, and therefore the force necessary to move the cube, actually increases.
The same phenomenon occurs with tool blades. If you sharpen and polish your blades past a particular point, the friction and heat produced during the cut between blade and wood will increase, as will the energy that must be expended, while the resulting quality of the cut and durability of the cutting edge will not improve significantly. Of course, the time and money invested in stones spent sharpening past this point will be mostly wasted.
The Inflection Point
The inflection point where additional polishing yields increased friction with little improvement in cut quality will depend on your tool and the wood you are cutting, but you can get a pretty good idea of where it is if you pay attention over time. While the sharpening stone manufacturers turn red in the face and salesmen froth at the mouth and spray spittle in anger when I say it, in my well-informed opinion there is little practical gain, beyond self-satisfaction, to be had from sharpening chisels or planes past 6,000~8,000 grit, making this range of grit an inflection point in my mind. What about you?
Conclusion
I encourage Beloved Customer to conduct your own experiments to determine the inflection point in the case of your planes and wood you cut. Many who figure this out save themselves significant amounts of time and money sharpening over the long-term.
To those Gentle Readers that love sharpening more than woodworking, and enjoy putting money in the pockets of sharpening stone manufacturers more than keeping it for themselves, I apologize for pointing out the icky floater in the punch bowl. But you probably would have it noticed it eventually anyway, if only from the taste difference.
I will touch more on this important point in the next exciting installment in this scientificish adventure.
YMHOS
The Repentant Mary Magdalene by Canova
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may frogs infest my boots.
Geographic UraChisel Ura. The term “Ito-ura” refers to the narrow land located immediately behind the cutting edge.
If a craftsman wants to do good work, he must first sharpen his tools.
Confucius, The Analects
We talked about the Ura in the previous article in this series (Part 9).
It is a defining detail in most Japanese woodworking blades, and one we must understand if we are to efficiently sharpen them, so in this post we will examine this important feature in more detail.
What is the Ura?
Japanese plane and chisel blades have a unique and intelligent design feature at what is called the “flat” on Western plane and chisel blades, and is called the “Ura” (pronounced oo-rah) in Japan.
Ura translates into the English language as “bay,” as in a protected area where the sea meets the shore. At the center of the ura is a hollow-ground, depressed area in the hard steel hagane layer called the “Uratsuki,” meaning the ura hollow, that serves two purposes.
One purpose of this design is to make it easier to keep the blade’s “flat” (the shiny areas surrounding the depression) planar (in the same plane).
If you pay attention when sharpening your wide Western chisel and plane blades lacking the Ura detail you will notice that, after many sharpening sessions, the blade’s flat, which was once planar, tends to become convex with a high point at the flat’s center making it difficult to keep the extreme cutting edge, especially the corners of the blade, in close contact with the sharpening stone. Yikes!
This doesn’t occur because you don’t know how to sharpen your blades, or because of pernicious pranks by pesky Pixies, but simply because your sharpening stones/platens/paper tend to abrade the blade’s perimeter more aggressively than the center. The resulting curvature makes it more difficult to polish the flat’s extreme cutting edge. Major buzzkill.
Because of the most excellent Ura, Japanese woodworking blades are quickly fettled initially and tend to stay planar without a second thought for many years of hard use, an important benefit if you count your time worth anything.
Another purpose of the Ura is to reduce the square inches or square millimeters of hard steel you must polish during each sharpening session. As you can see from the photo above, the shiny perimeter land is all that touches the sharpening stone. Compare this with the black area which doesn’t touch the stone. That’s a lot of hard steel you don’t have to deal with. Besides making the job easier, it also saves a lot of time when sharpening and helps one’s expensive sharpening stones last longer. Time is money and stones ain’t cheap, as my old foreman scolded (lovingly, I’m sure).
Even if you don’t use your tools to make a living, you should at least recognize that time spent sharpening is time making wooden objects lost.
The Downside Of the Ura
A worn-down multiple-ura chisel
Despite my poetic praise, the Ura detail is not all blue bunnies and fairy farts, because it does have one unavoidable downside: Over many sharpening sessions the Ura unavoidably becomes gradually shallower, and the lands surrounding the Ura on four sides become correspondingly wider. Nothing lasts forever except regrets and taxes.
It is not uncommon to see old chisels and plane blades with the hollow-ground area of the Ura almost disappeared. You can postpone this day by sharpening the Ura wisely. However, in the worst case where the Ura disappears entirely, you will still be left with an entirely usable Western-style flat, so not all is lost.
In the case of plane blades, unless the plane’s ura is subjected to a brutal sharpening regime, the land that forms the cutting edge (called the “Ito ura” meaning “strand” as in a flat area on a riverside, in Japanese) tends to gradually become narrower, and even disappear entirely after numerous sharpenings. Of course, when this happens, the blade loses its cutting edge, and the land must be restored by “uradashi” (oo-rah-dah-she) aka “tapping out” or bending the cutting edge towards the ura side, and then grinding it flat to form a new ito-ura land. Tapping out a blade requires some caution, but is not difficult. We will discuss the how-to of this aspect of blade maintenance in a later article in this series.
In the case of chisels, which have smaller and shallower ura compared to wider plane blades, the land at the cutting edge does not typically require tapping out, although it’s certainly possible to tap out wider chisel blades. Narrow chisel blades, on the other hand, are difficult to tap out without damaging them due to the rigidity produced by the hard steel layer (detailed in the previous post in this series) wrapped up the blade’s sides.
Mitsuura Chisels
Ichimatsu Nomi Ura (by Kiyotada). After many years of hard use, the multiple ura (aka “mitsuura”) on this oft-sharpened chisel used to pare precision joints has become shallower and the planar lands have become wider. Still entirely useful, it now takes more effort to sharpen than when new.Spearpoint Mitsuura chisels made by Sukemaru using EDM technology. Sadly, Mr. Usui no longer produces them.
Some chisels are made with multiple ura, typically called “mitsuura” meaning “triple ura.” Mitsuura chisels are more difficult to sharpen than chisels with a single ura because the total area of hardened steel that must be polished is comparatively larger. The ura of mitsuura chisels also tend to wear-out quicker than single-ura chisels because each individual uratsuki is shallower in depth than standard uratsuki. They look cool, but I am not a fan of multiple ura except in a few specific applications.
In the next stage of our journey into the mysteries of sharpening, we will wander through the metaphysical realms of the “Fae.” A word of caution: Be sure to have a brass bench dog in your pocket when you leave the well-lighted pathways and accept neither food nor drink from anyone’s hand until we return, not even a cheeseburger with fries. ☜ (◉▂◉ )
YMHOS
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may I drown in my own uratsuki.
A piece of hot high-carbon steel, which will become the cutting edge, has been placed on the orange-hot low-carbon steel body of a knife as part of the “forge-welding” process. An acidic flux powder has been placed in-between and on the metals in preparation for laminating them together into a single blade.
Men are like steel. When they lose their temper, they lose their worth.
Chuck Norris
While Beloved Customers are of course familiar with the features of the high-quality woodworking blades we purvey, some Gentle Readers may have little knowledge of the important details essential to Japanese woodworking tools. So in this article we will try to remedy that by examining some simple historical points common to woodworking blades around the world, as well as some details that make Japanese blades unique.
Your humble servant believes an understanding of these basic facts will aid Beloved Customer’s sharpening efforts, or will at least tickle Gentle Reader’s interest in Japanese blades. Please comment and let me know your thoughts.
Laminated Bi-Metal Construction
As discussed in previous articles in this series, before technological advances in the 1850’s steel was difficult to make and expensive. Consequently, it was standard practice not only in Japan but everywhere, including Europe and the United States, to reduce production costs by minimizing the amount of precious steel used in producing all types of edged tools including axes, scythes, handplanes and chisels etc.. This was achieved by laminating smallish pieces of high-carbon steel to softer and much cheaper wrought-iron bodies through a process called “forge welding.” The photo at the top of this article shows the blacksmith placing the piece of high-carbon steel on the softer iron body of a blade prior to beating the hell out of it as part of this process.
Most chisel and plane blade blacksmiths in Japan continue to employ this lamination technique even today, not because of some navel-gazing infatuation with the archaic, but because it has serious advantages.
The best Japanese plane and chisel blades are generally comprised of a layer of very hard high-carbon steel called “hagane” (鋼) in Japanese, forge-welded to a softer low-carbon/no-carbon iron body called “jigane” (地金). We discussed both of these metals in the previous two articles in the series hereand here.
Here is the key point to understand: When a blade made from a lamination of high-carbon and low/carbon steel is quenched, the sudden temperature change causes the high-carbon steel layer to become hard, even brittle, while the softer low/no carbon layer is unaffected and remains soft.
A 30mm Hidarino Ichihiro Atsunomi, approximately 12″ OAL.
Why go to so much trouble? One advantage of this construction is that it allows the cutting edge to be made much harder than is possible in the case of an non-laminated blade therefore staying sharper longer in use than softer blade. But why does lamination make this possible? Consider the absolute fact that a chisel blade made of uniform material heat-treated to a uniform hardness of, say, HRC65 might cut very well, and stay sharp a long time, but it will always break in use. Not just chip, but actually break in half. The softer low/no carbon jigane layer supports and protects the hard high-carbon layer preventing it from rupturing. Such durability is a huge advantage.
Another benefit of laminated construction is ease of sharpening. Remember, the harder a piece of steel is, and the larger its area, the more work it takes to abrade it. But in the case of a laminated blade, the amount of hard-steel exposed at the bevel the user must abrade is just the relatively thin strip of shiny metal seen in the chisel photos above and below. Please also recall that the darker low/no carbon layer jigane is dead soft and melts away on the sharpening stones without much effort.
So the laminated construction of hard hagane to soft jigane produces a blade that is tough but at the same time hard, one that will become very sharp and stay sharp a relatively long time thereby improving work quality and productivity while at the same time reducing the time spent sharpening.
BTW, this is not a technique that was invented in Japan, it’s just the Japanese blacksmiths that continue to employ this ancient and clearly superior technique, at least, that is, for a little while longer. A word to the wise.
A 42mm Hidarino Ichihiro Oiirenomi
Laminated Blades in the West
If you have examined antique plane blades with wooden bodies you may have noticed many have blades stamped ” Warranted Cast Steel”
Despite being designated “cast steel” in England and America in past centuries, unlike Conan’s Daddy’s sword, or the orc blades made in the bowels of Isengard, plane, chisel and saw blades with this mark were not “cast” by pouring molten metal into a mold to form a blade. Rather the process to make the steel involved melting iron ore in a crucible and pouring it into molds “casting” a strip, bar, or ingot of high-carbon steel which is then forged to make the blade, hence the name.
This became possible only when the technology required to reliably and fully melt steel to a more-or-less liquid state on an industrial scale was developed. Such steel was also called “Crucible Steel” after the crucible container used to melt iron ore.
This technology was widely used in the United States and Europe through the 1870’s. In fact, one steel mill is said to have been producing crucible steel until the 1960’s. Toolmanbloghas an interesting summary on cast steel.
With few exceptions, these plane blades have a thin piece of high-carbon steel forge-welded to a soft wrought iron body, very similar to Japanese plane blades. I have reused a couple of these antique blades to make Krenovian planes and testify of their excellent cutting ability.
Chisels were also once made in Europe using this same lamination technique, although fewer examples remain extant.
Axes, hatchets, and many farming implements were also mass-produced up until the 1920’s in the US using a variation of this same technique with a “bit” of steel forming the cutting edge laminated to or sandwiched inside a body of low-carbon steel or wrought iron. Axes are still made this way in Japan. It’s a proven technique with a lot of advantages, but it does require a skilled blacksmith to pull off successfully.
The point I am trying to make is that blades made using forge-welded laminated technology were the very best available in Europe and the United States for many centuries.
Here is a link to a blog post by Paul Sellers where he praises the old chisels and laments the new.
U-Channel Construction
A closeup of the 42mm Hidarino Ichihiro Oiirenomi showing the lamination line between the steel cutting layer and low-carbon steel body of the bladeThe same 42mm Hidarino Ichihiro Oiirenomi. Notice the hard-steel lamination wrapped up the blade’s sides to add rigidity.A 30mm Hidarino Ichihiro Atsunomi, approximately 12″ OAL. Notice the hard steel lamination forming the cutting edge at the bevel. This is a beautiful lamination.A beautiful hand-filed shoulder detail typical of Yamazaki-san’s work
The shape of the hard steel cutting layer laminated to the softer low-carbon steel (or wrought iron) body of chisels was historically a simple flat plate in Western blades. This is still the case for Japanese plane blades, axes, and farming implements. But if you imagine Japanese blacksmiths would be satisfied with such a simple design for all applications, you don’t know them well.
If Beloved Customer will carefully consider the blades pictured in the four photographs above, you will notice the lighter-colored hard steel lamination wrapped up the chisel’s sides forming a “U channel” of hardened steel adding necessary rigidity and strength. This is a critical detail for Japanese chisels intended to be struck with a hammer. Interestingly, Japanese carving chisels are not typically made this way, and are consequently structurally weaker.
Plane blades are not subjected to the high loads chisels experience and so would not benefit from this structural detail.
The Ura
Japanese chisel and plane blades, among others, typically have a hollow-ground depression called the “Ura” (pronounced “ooh/rah”) which translates to “ocean” or “bay,” located at what is called the “flat” on Western blades. Notice the polished hard steel lamination extending from the cutting edge to several millimeters up the neck. The black area surrounded by the shiny lands is the same hard metal, but has been hollow-ground to form the swamped ura.
This clever and effective design detail is unique to Japanese tools to the best of your humble servant’s knowledge. We will look at this design detail more in the next article in this series.
The Point
What does any of this have to do with sharpening? Allow me to focus what we have discussed previously.
These design details cleverly turn potential disadvantages into distinct advantages you need to understand when sharpening Japanese woodworking blades.
For instance, the layer of high-carbon steel laminated into our chisels and planes is usually 65~66 HRc in hardness. Western blades are made of a single piece of steel heat-treated to approximately 50~55 HRc to make the tool softer/tougher thereby limiting breakage while sacrificing the longevity of a blade’s sharp edge, the most significant performance criteria in a quality cutting tool, significantly. The extra hardness of the Japanese blade helps it stay sharper longer, an important benefit if your time is worth anything. This is good.
But if the entire blade were made of a solid piece of this extra-hard steel, it would a royal pain in the tukus to sharpen, I guarantee you. It would also break. Oh my, that would be bad.
The softer low-carbon/no-carbon steel or iron jigane body, however, is much softer and easily abraded making it possible to keep the hard steel layer thin, and therefore easily abraded, while protecting it from breaking. This is good.
Unlike the blade’s bevel, however, the ura (or “flat” as it is called in Western chisels) is all one-piece of hard steel. Without the hollow-ground ura depression, you would need to abrade all that hard steel at one time to initially flatten and regularly sharpen the blade, a necessity I guarantee would ruin your mellow mood even if you consumed massive quantities of controlled substances with the fervor Beldar and Prymaat exhibit when sucking down triple-ply toilet tissue. But with the addition of the ura detail, we only need to abrade the perimeter planar lands (the shiny areas in the photos above) surrounding the ura. This is exceedingly good.
The ura depression makes it easier and quicker to not only sharpen the blade, but also to keep the “flat” planar (in a single plane). Without the ura, such a hard blade would be difficult to maintain planar and frustrating to sharpen. With the addition of the ura, however, the blade is genius.
An important skill to learn when sharpening Japanese blades is how to maintain the lamination and ura effectively. We will discuss this subject more in future posts, including the final article in this series.
Conclusion
If you didn’t learn at least three new things from this post then you are either very smart or weren’t paying attention. ¯\_(ツ)_/¯
In the next installment in this bodice-ripping tale of romance and derring-do we will examine the hollow-ground “Ura” in more detail. It’s important enough to deserve a special post.
YMHOS
It is not my intention to be fulsome, but I confess that I covet your skull.” ― SirArthur Conan Doyle, The Hound of the Baskervilles
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may I cough up a hairball during every meal.
The fissured and cracked jigane of a 70mm plane blade forged by Usui Kengo, another Niigata blacksmith (RIP). Notice the rod which retains the chipbreaker is non-existent, replaced by two short stubs. An elegant detail in this plane body by Ito-san (Soh 宗).
If you can’t explain it to a six year old, you don’t understand it yourself.
Albert Einstein
In the previous article about sharpening Japanese woodworking tool blades we looked primarily at the nature of the hard high-carbon steel used in making woodworking blades. In this post your humble servant will try to dispel some of the confusion that surrounds the other metal used in making most Japanese knives, axes and woodworking blades, namely the soft low-carbon/no-carbon steel called “Jigane” (地金). I hope this brief explanation will improve Beloved Customer’s understanding of some Japanese tools and aid your sharpening efforts.
Sources of Jigane
Most Japanese woodworking blades, and many knives, are comprised of a thin piece of hard high-carbon steel, discussed in your humble servant’s previous article in this series, forge-weld laminated to a larger and thicker piece of softer low-carbon steel or wrought iron called “Jigane” (jee/gah/neh 地金) in Japanese, which translates directly to “ground metal.”
We will discuss this bi-metal lamination more in the next post in this series, but for now take my word that it is essential to the performance of many types of Japanese cutting tools nowadays, and for many centuries was also critical to manufacturing cutting tools in America and Europe as well.
The best jigane material for plane blades is said to be scrap iron salvaged from the boilers of old trains, boats, and factories, etc. having been subjected to thousands of heating and cooling cycles during decades service driving out most of the carbon, indeed making the iron very soft to the point of weakness.
The most desirable jigane for plane blades is therefore called “tired” iron, named so because it is not only soft, but because it looks weak and exhibits a visible grain along with cracks and imperfections which those well-versed in Japanese plane blades covet.
A pile of jigane, probably old salvaged structural steel. Looks like boards of old wood, but it ain’t.
Wrought Iron Production
Nowadays, this very low-carbon steel, also known as “ wrought iron,” is not produced in any volume for several reasons. First, demand is just too low to make it worthwhile to manufacture. Hand-forged ornamental iron is the only commercial usage besides Japanese tools of which your humble servant is aware, relatively microscopic markets. In fact, a constant complaint from ornamental iron producers is the difficulty of working the relatively hard material available to them nowadays.
The second reason is that steel production processes have changed drastically in the last 150 years. For instance, it used to be that steel began as iron ore, basically rocks, which were crushed, melted and refined into wrought iron, an intermediate product of steel production. Indeed, at the time this low-carbon product was much less expensive to produce than high-carbon steel and so was used for everything from the boilers, bridges, trains, ships and anchor chains mentioned above to axes, chisels, farming implements, machinery, what’s called “miscellaneous metals” in the construction industry, and of course plane blades. There are still a few surviving structures around that were made using this weaker material.
Nowadays, things are different. With high temperatures more easily attainable than they were prior to the 1850’s, manufacturing techniques have advanced to the point that carbon is incorporated into the steel automatically entirely eliminating the low-carbon wrought iron intermediate product.
Also, scrap metal has become critical to steel manufacturing processes nowadays. Remember what happened to steel prices worldwide when bloody-handed China was buying up huge volumes of scrap metal worldwide for its Olympic infrastructure building projects?
I think we can agree that this energy-efficient cost-reducing recycling of natural materials is a very good thing. But it does have a tiny downside, namely that most commercial scrap metal available in any useful volume today has been cycled through the modern steel-manufacturing process many times and already contains not only high levels of carbon, relatively speaking, but alloys such as chrome, molybdenum, and nickel from previous melting pots. Indeed, undesirable chemicals such as phosphorus, sulfur and silica tend to be high in typical scrap metal, not much of a problem for use in the construction, automotive, and shipping industries but a serious problem for tool steels.
In summary, wrought iron simply isn’t made anymore because it is neither an intermediate product nor a profitable one.
Japanese blacksmiths making high-quality plane blades nowadays mostly use wrought iron recycled from old anchor chains, old iron bridges, or other recycled structural components. If you see a hole in a plane blade, like the extra-wide plane blade pictured below, it once housed a rivet. Yes, structural steel was once connected with hot rivets instead of bolts. Hi-tensile modern bolts are decidedly better if less romantic.
A plane blade with an old rivet hole in its face, probably from an old iron bridge that once stood in Yokohama and which was recycled many years ago.
Plane Blades
A plane blade by Ogata-san in his “Nami no Hana” series using a special version of Swedish Asaab K-120 steel. Notice not only the fissures and defects, but also the striations and grain typical of soft, tired “wrought iron.”
Mr. Takeo Nakano (see his photo below) makes our plane blades. He is a kind, unassuming man in the best tradition of Japanese craftsmen with the outward appearance of a sedentary grandfather, but when using hammer and tongs at his forge within his dark and smoky smithy, his posture and visage resemble that of an intense Vulcan reinforcing the steel gates barricading the world of light against a demon onslaught. Oh my!
Like nearly all the plane blacksmiths in Niigata, he uses scrap iron obtained in a single lot many years ago from an iron bridge that was dismantled in Yokohama Japan.
Mr. Nakano at home
I am told that most of the jigane used for plane blades in Hyogo Prefecture is old recycled anchor chains from a ship knacker.
The back of the same Usui plane blade. Notice the cracks and voids visible in this excellent jigane exposed at the polished bevel. Very wabi-sabi. This jigane was once part of an iron bridge in the city of Yokohama, Japan.
In the case of plane blades, structural strength is not critical, so laminating a thin layer of high-carbon steel forming the cutting edge to a soft iron body is adequate. Indeed, the thicker the hard steel layer, the more time and effort it takes to sharpen the blade, so in a high-quality blade the thicknesses of the high-carbon steel layer and the soft jigane body will be carefully balanced to ensure the blade’s bevel rides the sharpening stones nicely and can be quickly abraded.
More inexpensive plane blades are forged using the same strip jigane used for chisels, a material harder than the ideal for plane blades.
Chisel Blades
In the case of chisels, while ease of sharpening is still important, the body and neck must be harder/stiffer to prevent them from bending, so a different, stiffer variety of jigane with a higher carbon content and fewer defects is used, and the steel layer is typically made thicker.
The jigane used by our chisel blacksmiths is a commercial product not produced anymore (thank goodness they have stockpiles) called “gokunantetsu” 極軟鉄 which translates directly to “extremely soft iron.” With a carbon content of 0.04~0.07%, a better description would be “very low carbon steel.” When heated and quenched, it doesn’t harden significantly.
The adventure will continue in the next exciting episode where we will bring it all together into a blade. Don’t forget to have popcorn and jujubes on-hand!
YMHOS
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may the fleas of a thousand camels infest my crotch.
An Alchemist and his assistants working late at night in his workshop.
Behold, I have created the smith that bloweth the coals in the fire, and that bringeth forth an instrument for his work.
Isaiah 54:16 KJV
In the previous post we looked at some of the supernatural aspects of making and forging steel. In this post we will examine some alchemical aspects of woodworking blades, in the particular the iron and steel used to make them and the related chemistry of sharpness and sharpening.
This post could be very technical, but your humble servant has simplified the description of chemical processes to make it easier for the non-technical Gentle Reader to follow. Please bear with me.
The Alchemy of Mutating Iron to Steel
When carbon is combined with iron in the right proportion, steel is formed. This mutation is easily accomplished nowadays, but for most of human history it was a fiendishly difficult, chancy, expensive process. No wonder those who could accomplish the deed were attributed with magical powers.
But just mixing chemicals does not yield a useful cutting tool. No, the blacksmith must make the steel hard enough to hold a cutting edge, but tough enough to endure actual work. The catalyst for this mutation is heat. The ability to create a fire hot enough to melt iron was, until fairly recently on the scale of human history, the biggest hurdle to producing quality steel consistently.
If steel is heated to within a specific range of temperatures (difficult to measure by eye) and then suddenly cooled, crystalline structures containing small, very hard and relatively brittle crystals called carbides form within a softer matrix of iron. These hard carbides supported in this rigid crystalline structure are what do the serious job of cutting, not the softer matrix.
At the extreme cutting edge, this structure might be compared to a modern circular saw blade comprised of a relatively soft body to which is attached very hard tungsten carbide cutting tips.
A steel blade dulls when the crystalline structure either shatters, or the pressure and friction of cutting wears away or cracks the softer supporting matrix, allowing the carbides to be torn from the matrix leaving behind gaps of soft, blunt metal. The larger the carbide clumps are and the greater the distance between them, the more easily they are shattered and torn away, and the duller a blade becomes with each crystal’s failure.
In a low-quality blade, and given the same amount of carbon in a fixed volume of steel, the crystals will form into relatively large and isolated clumps separated by wide rivers and lakes of softer metal, as seen from the viewpoint of a carbide. The steel will crack along these weaker pathways when stressed, and when cutting, the softer material in these lakes and rivers will erode first, leaving the desireable carbide clumps unsupported and more vulnerable to failure.
A photograph of Shirogami No.2 high-carbon steel following heat treatment and tempering. In this case, the temperatures used were less than ideal resulting in the irregular crystalline structure shown. The black material is carbon, the grey material is converted steel, and the whitish areas are soft, unconverted iron, points of natural weakness and paths of failure in the steel blade, not acceptable in a high-quality hand-forged blade.The same steel shown above but following quenching and tempering using proper temperatures. The converted steel crystals are small and more evenly distributed. Islands of unconverted carbon and lakes of soft unconverted iron do not remain. This is a sample of ideal high-carbon steel, and is typical of the crystalline structure of the blades of our chisels, planes and kiridashi.
In a high-quality steel blade, by comparison, and given the same amount of carbon in a fixed volume of steel, the crystalline clumps are comparatively smaller and distributed more evenly throughout the matrix making it more resistant to erosion, and the carbide crystals more resistant to damage. Such steel is called “fine grained,” and has been highly prized since ancient times for its relative toughness and ability to become very sharp and stay sharp for a long time. This is the steel preferred by woodworking professionals in Japan and is the only kind found in our tools. Without exception.
Sadly, this crystalline structure is not visible to the naked eye, and anyone who says differently is trying to sell Beloved Customer something brown and smelly, probably with a side dish of flies.
Impurities and Alloys
Other than excellent and abundant water, endless forests, mountains overgrown with wonderful trees, and diligent people, the islands of Japan are poor in most of the natural resources critical to industrialization, including iron ore, coal, and petroleum. Prior to the mass importation of such resources after 1854, the best source of iron in Japan had been black sand (satetsu 砂鉄) found in rivers. The article at the following link details some of these traditional Japanese production methods: A Story of a Few Steels
Regardless of their source, all iron ores naturally contain impurities such as phosphorus, sulfur, or silicon to one degree or another. When these impurities exceed acceptable limits, they can weaken the steel, make it brittle or tend to warp badly, or make heat treating results inconsistent. They are often expensive to remove.
Nagasaki Bay, the only Japanese port open to Western traders between 1639 and 1854, with primarily only Dutch ships permitted entrance.
There are three approaches commonly used to minimize the negative effects of these difficult-to-remove impurities. The first is simple avoidance of the problem by employing iron ore and scrap metal free of excess amounts of these contaminants. Such ore and scrap are available, but they are not found everywhere and are relatively expensive. For centuries, the purest iron ore has been mined in Sweden.
The second approach is to add purer iron or carefully sorted and tested scrap steel to the melting pot thereby reducing the percentages of the harmful contaminants, a technique called “ solution by dilution.”
Nakaya Takijiro’s saw forge, originally made for forging swords
The third fix is to add chemicals such as chrome, molybdenum, nickel, tungsten, vanadium and even lead to the pot forming steel “alloys” to help overcome the detrimental effects of natural impurities, specifically those related to brittleness, warping and unpredictable heat treatment. Some additives will make the steel more resistant to abrasion and corrosion, or even easier to cast, drop-forge, or machine.
Some steel alloys have serious advantages over plain high-carbon steel in mass-production, for example reducing material costs by allowing the use of cheaper lower-grade iron ore and scrap metal, or improved working and heat-treating characteristics making it possible to achieve higher productivity with fewer rejects even when worked by low-skill workers.
But the addition of these chemicals is not all blue bunnies and fairy farts because edged tools made from high-alloy steels typically have some disadvantages too. For instance, additives like chrome, nickel, molybdenum, vanadium and especially tungsten are costly. And due to the crystalline structure that develops in many high-alloy steels, products simply cannot be made as sharp as plain high-carbon steel, and are more difficult and time-consuming to sharpen by hand.
Some manufacturers cite the higher costs of high-alloy steels to justify higher prices for their products. However, what they never say out-loud is that labor costs are much much less when using high-alloy steel because skilled workers are not necessary. And because high-alloy steels produce fewer rejects, quality control is easier, overall productivity is higher, warranty problems are fewer, and profitability is increased. Indeed, without high-alloy steels, manufacturers would need to train and hire actual skilled workers and professionals instead of uneducated seasonal workers thereby destroying the Wally World mass-production model that is the foundation of modern society. Egads! Walmart’s shelves would be bare!
Our blacksmiths are not part of the Wally World production model, but make only professional-grade tools for craftsmen that value ease of sharpening, edge retention, and cutting performance above corporate profits. They charge more for plain high-carbon steel blades than for high-alloy steel products because labor and reject costs are higher.
So if a manufacturer brags about the excellence of the high-alloy steels they are using, rest assured increased profits are their motivation, not improved cutting performance. Caveat emptor, old son.
Japanese Steels
The best plane and chisel blades are made from plain, high-purity, high-carbon steel. In Japan, the very best such steel is made by Hitachi Metals mostly using Swedish pig iron and carefully tested industrial scrap (vs used rebar and old car bumpers), and is designated Shirogamiko No.1 (白紙鋼 1 号 White-label steel No. 1). They also make a steel designated Shirogami No.2 steel containing less carbon. Another excellent steel for plane and chisel blades is designated Aogamiko No.1 steel (青紙鋼 Blue-label steel).
Aogami steel, like Shirogami steel, is made from extremely pure iron, but a bit of chrome and tungsten are added to make Aogami steel easier to heat treat with less warping. Aogami can be made very sharp, but it is not quite as easy or pleasant to sharpen as Shirogami. Some of the plain high-carbon Swedish steels are also excellent.
If worked expertly, either of these steels consistently produce the highest quality “fine-grained” steel blades.
Let’s compare the sharpening characteristics of these two steels. To begin with Shirogami steel is easy, indeed pleasant, to sharpen. It rides stones nicely and abrades quickly in a controlled manner.
Aogami steel, by comparison, is neither difficult nor unpleasant to sharpen, but it is different from Shirogami steel in subtle ways. It takes a few more strokes to sharpen, and feels “stickier” on the stones, but it will still produce fine-grain steel blades and performs well.
Inexperienced people lacking advanced sharpening skills typically can’t tell the difference between blades made from Shirogami, Aogami or Swedish steel and steels of lesser quality. But due to the difficulty of forging and heat treating Shirogami or other plain high-carbon steels, a blacksmith that routinely uses them will simply be more skilled and have better QC procedures than those whose skills limit them to using only less-sensitive high-alloy steels.
Professional Japanese woodworkers insist on chisel blades made from Shirogami No.1 steel. Some prefer Aogami No.1 for plane blades believing the edge holds up a bit better. At C&S Tools our plane blacksmith prefers to use Aogami because it is easier to work and more productive (especially in the case of carving chisels), but for a little extra they are happy to forge blades from Shirogami Steel.
I own and use Japanese planes made from Shirogami, Aogami, Aogami Super, Swedish steel, and a British steel called “Inukubi,” which translates to “dog neck,” a commercial steel imported to Japan from England (Andrews Steel) in the late 1800’s. Of these, Shirogami No.1 steel is my favorite. It’s a matter of personal taste.
Beware of a plane or chisel blacksmith that refuses to use plain high-carbon steel and tries to charge you more for blades made from Aogami or Aogami Super steel.
The Challenges of Working Plain High-Carbon Steel
What makes plain high-carbon steel so difficult to work, you ask? Your humble servant has never even forged a check much less a tool blade, but I will share with you what the blacksmiths I use and swordsmiths I know have told me in response to this question.
First, plain high-carbon steel is much more difficult to successfully heat treat because the range of allowable temperatures for forging and heat-treating is narrow. Heat it too hot and it will “burn” and be ruined. Quench it at too high or too low a temperature and it will not achieve the desired crystalline structure and/or hardness. Miss the appropriate range of temperatures and the blade may even crack, ruining it. Yikes! Please see the numbers and photos in the article linked to above.
Second, even if the temperatures are nuts-on, plain high-carbon steel has a nasty habit of warping and cracking during heat treating resulting in more rejects than alloy steels with additives such as chrome, tungsten or molybdenum. Strange as it may seem, when the crystalline structures that make steel useful form during quenching, they increase the blade’s volume. This change produces differential expansion causing the metal to warp, a troublesome characteristic that can be more or less controlled, or at least compensated for, by a skillful blacksmith, but it takes real skill, extra work, and a bit of luck. Not just any old Barney can do it consistently, so when working plain high-carbon steel, a blacksmith needs to know his stuff and pay close attention.
Other than wastage due to rejects, it doesn’t cost more to forge and heat-treat a blade made from plain high-carbon steel, but it takes serious skills and dedication to quality control to make a living working it for 5+ decades.
Let me give you an example of skill and experience as it relates to warpage management of plain high-carbon steel.
The photo below is of a swordsmith the instant before he quenches a glowing hot sword blade made of tamahagane, a traditional type of plain high-carbon steel made from iron sand, in a water trough. Notice the condition of his smithy: he is working in the middle of the night, the time when the best magicians and alchemists have always done the most difficult jobs because temperatures are easier to judge without inconsistent sunlight confusing things. His posture and facial expression are tense because he is about to roll the bones and, in the blink of an eye, either succeed in the most risky part of making a sword, or fail wasting weeks or months of work and thousands of dollars worth of materials. Notice how straight the glowing blade is before the plunge.
A Japanese swordsmith with a blade made from high-carbon Tamahagane steel poised for quenching. The blade is straight at this point in the process. He has invested months of work into this blade to this point and a misjudgment or even bad luck in the next second can waste it all. Not a job for the inexperienced or timid.
Note that the quantity of crystalline carbides formed in a Japanese sword during the quench is greatest nearest the hard cutting edge, and cause that area of the blade to expand and warp the most. The swordsmith therefore forges the blade straight before quenching it in expectation of it warping to the intended curvature when the crystalline structures at the cutting edge form, as seen in the photo below. This curvature is an intentional design feature that takes years of experience to achieve in a controlled manner.
After quenching, the resulting warpage is dramatic. The swordsmith must plan for this distortion and shape the blade accordingly prior to the quench if he is to avoid unfortunate results. Tool blacksmiths are faced with the same challenges on a smaller scale but more frequently. Notice the mud applied to the blade before quenching intended to control the formation of crystalline structures and achieve differential hardness. The patterns the swordsmith made in applying this insulating mixture heavily influence the limits of differential heating in the blade as well as the appearance of the “hamon” pattern that develops.
If the swordsmith intended to make a straight sword blade, he would have a forged a reverse curvature into the blade to compensate for the warpage that occurs during quenching. Plane and chisel blades exhibit similar but less dramatic behavior due in part to the moderating effects of the low/no-carbon lamination.
A photo of both sides of a modern sword with the warpage being an intentional design feature
The thinner the piece of steel being heat-treated, the more unpredictable the warpage developed and more likely the blade will be to develop fatal cracks. Within limits, simple warpage can be corrected to a limited degree in thin blades during the first few seconds after quenching and/or tempering by bending and/or twisting the blade while it is still hot and malleable. These techniques do not work well in the case of thicker plane and chisel blades, however, so experienced blacksmiths don’t rely solely on corrective measures but anticipate warpage beforehand and create a curve or twist in the opposite direction when forging the blade to compensate. This takes skill and experience, and even then, some rejects are unavoidable.
Chemical alloys like chrome, molybdenum, and tungsten greatly reduce warping and the risk of cracking, so their benefits are huge.
None of this is mystical, but tools made from plain high-carbon steels such as Shirogami steel require more skill and experience than those possessed by factory workers, much less Chinese peasants, so mass-production is nearly impossible, labor costs are higher, profit margins are smaller, and advertising budgets are non-existent. No wonder such tools get little attention from the shills in the woodworking press.
While modern chemistry has unveiled the mystery of steel, it has only been during the last 70 years that metallurgical techniques were developed making it possible to understand the Mystery of Steel, and the tools to scientifically control the Alchemy of Steel are only a few decades old, a short period of time in human history.
The manufacture and working of steel are still magical processes that are the foundation of modern civilization. Be not deceived: while computer nerds and ijits with MBAs take all the credit, without the alchemy of steel and the skill to work it, human life on this planet would be short and brutal.
If you have good sharpening skills but haven’t yet tried chisel or plane blades made from Shirogami, Aogami or Asaab K-120 Swedish steel, you’re missing a treat.
In the next article in this magical series we will examine the genius of the soft iron component found in quality Japanese woodworking blades. Whether cat, bat or owl, please explain the details to your familiar to prepare them for the excitement to come!
YMHOS
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may everything I eat taste like mud.
“The most beautiful experience we can have is the mysterious. It is the fundamental emotion that stands at the cradle of true art and true science.”
Albert Einstein, The World as I See It
The blades we are considering in this series of articles about sharpening are made from iron and steel, so it makes sense to examine these materials from the viewpoints of sharpness and sharpening. But let’s begin by consider some of the interesting supernatural and legendary aspects of working these materials first.
Steel Magic
Steel is a magical substance. Since ancient times, the blacksmiths that worked it were sometimes seen as gods, sometimes as wizards, and always as essential. Regardless of local traditions, the power blacksmiths possessed to combine and shape the elements of earth, wind, water, fire and even spirit into the tools and weapons of everyman’s trade was seen as magical.
Even the blacksmith’s forge and anvil were seen as magical in and of themselves, and rituals incorporating them were widely believed to keep evil at bay, provide good luck and blessings, and even to cure ailments.
There were several extremely famous magical blacksmiths back in the mists of time. Please allow your humble servant the honor of presenting two of them.
Vulcan the God
Vulcan (aka Hephaestus to the Greeks), Roman god of fire and blacksmithing. Archaic relief from Herculaneum (National Archaeological Museum, Naples).
The bas-relief stone carving in the photo above is of Vulcan, the Roman god of fire and blacksmithing, also known as Hephaestus to the Greeks. This carving was excavated at Herculaneum, located in the shadow of Mount Vesuvius near Pompeii. Herculaneum was an ancient Roman town destroyed by volcanic pyroclastic flows in 79 AD. The word “volcano” comes from the word Vulcan, so a stone carving of Vulcan retrieved from a town totally destroyed by Vulcan’s namesake is tragically ironic in the extreme.
Die Schmiede des Vulkan (The Forge of Vulcan) by Velázquez, Diego 1599–1660) Museo del Prado, Madrid, Spain.
The painting by Diego Velázquez above is from a scene in the Roman poet Ovid’s Metamorphoses where the god Apollo visits the god Vulcan in his forge to tell him that Venus, Vulcan’s wife, is being naughty with Mars, the god of war. Apollo is on the far left and can be recognized by his crown of laurel and shining aura. Vulcan stands next to Apollo with a shocked and incredulous expression on his less-than-beautiful face (nice abs, but the ‘stache needs a lot of work). Vulcan’s assistants have stopped their work on a plate armor project (decidedly 15th century in style) astounded by both the sudden appearance of Apollo and the news he delivers.
Obviously, Venus and Vulcan were not a happy couple. Legend says that whenever Venus was unfaithful, Vulcan grew angry and beat hammer on anvil so fiercely that sparks and smoke rose up from the top of Mount Etna on the island of Sicily, under which he had built a forge, creating a volcanic eruption. You could say he blew his top (ツ).
Perhaps Apollo is sharing this tidbit of news just to help out his old buddy Vulcan, or perhaps his reason for snitching is malicious. Whatever the reason, I think it’s safe to assume people loved drama in the 1600’s too. Nothing new under the sun.
Your humble servant’s point is that Vulcan (Hephaestus) was not only worshiped in ancient Greece but had a presence in popular culture that ranged from before an Etruscan tribe drained the swamps that became Rome in the 10th century BC, to as late as the 1600’s. And I won’t even get into Trekkie lore. Now that’s an influential craftsman.
Wayland the Smith
Wayland the Smith (Vølund Smed) 1873 sculpture. Stockholm Sweden.
Wayland the Smith was another famous blacksmith, metalworker, and magician. He was said to be a Lord of the Elvish folk who learned his trade from either giants or dwarves.
While not as old as Vulcan in human history, Wayland’s legend survives throughout Europe, and the products of his forge were central to heroic traditions of many peoples and kingdoms long before the days of the Viking longboats.
He is credited in Norse, Germanic, and Anglo-saxon legends and literature with forging magical objects of great renown, including rings of power (no, Professor Tolkien didn’t invent the concept), the impenetrable coat of ring mail worn by Beowulf during his epic battle with Grendel, the magical sword named Gram that Sigurd used to slay the dragon Fafnir, and even King Arthur’s sword Excalibur. Not just scribblers, but even Alfred the Great, king of the Anglo-Saxons (c.886~899AD) on the island that would later become England, wrote of him.
The chains on the legs of the statue above probably represent his maiming and imprisonment on an island at the pleasure of an evil Norse king upon whom he took a bizarre revenge involving unconventional drinking bowls and jewelry. Is Wayland’s slavery one of the reasons blacksmiths have wrapped chains around their anvils since ancient times, or is the purpose just to secure the anvil and mute the bright ringing song they sing? Another mystery…
Wayland’s influence in modern times is not insignificant. For example, Leonardo Da Vinci’s fascination with flying machines was probably stimulated by the legends of Wayland building and using a winged contraption to escape his slavery. And unlike Daedalus’s deadly device in Greek legend, Wayland’s glue didn’t melt.
Daedalus (the bald nekid guy) and his son Icarus (the falling nekid guy) using wings to escape the island of Crete, home of labyrinths and monsters. Against his father’s advice, legend holds that Icarus flew too near the son melting the wax securing the feathers that made the wings function. “Oops,” Murphy chortled in his glee.
The legends of Wayland the Smith were once deadly serious matters.
In a lighter vein, the writings of J.R.R. Tolkien, the author of the most popular works of written fiction in human history (no kidding), were influenced by these same legends.
The Blacksmith’s Shop
While some blacksmithing traditions such as those involving Vulcan and Wayland are decidedly pagan in origin, others fit well with Christianity. For example, the ring of the blacksmith’s hammer on his anvil was once believed to strengthen the chains that bind the devil in hell barring him and his demons from God-fearing folk’s hearths. In darker times in human history the blacksmith’s workshop was believed by many to be a safe haven from evil forces, one that Satan and his imps actively avoided.
The village smithy. Notice the horseshoe on the wall in the background, and its downward orientation. Due to the lack of char marks on the wall, we can tell this is not where the smith normally hangs horseshoes to cool. There is method to the madness.
Below is a download link to a charming story about why blacksmiths ring their anvils and how to make sure a horseshoe brings you luck at work and at home. I encourage you to read it.
If you have ever spent time in small one-man traditional smithies of the sort where our blacksmiths labor to produce the tools we provide to our Beloved Customers then you know the other-worldly atmosphere typical of such workplaces. Imagine wattle and daub walls and exposed , twisting, rough-hewn wooden roof beams blackened with 70+ years of soot, the compacted but lumpy dirt floor, the darkness of carefully-managed sunlight (the better to judge metal temperatures by eye), the bitter smells of charcoal fumes, straw ash, flux, hot steel and smoking oil; the roar of forced gas forges; the sounds of grinders and the dangerous leather belt systems that drive them; and finally the terrible racket and vibration of spring hammers and ringing anvils. A man that could work alone in a place like that 12 hours a day for 65 years is not afraid of your garden variety demon, no siree Bob.
It’s quite a sight to see a craftsman working in such an environment. They often start late in the morning to avoid noise complaints from the neighbors, and work until late at night doing heat treating when sunlight won’t interfere with the colors of the hot metal.
By noon their arms are black to the elbows and charcoal smudges are on their faces. The sight of a small, wizened 82 year-old man with strong sinewy arms scowling into the face of yellow-hot steel as he hammers the hell out of it is like a scene from Dante’s Inferno. Something of the ancient magic of Vulcan and Wayland can be felt in such places.
In the next post we will examine some alchemical aspects of the Mystery of Steel. Until then, I have the honor to remain,
YMHOS
Mr. Junichi Takagi, Japan’s last adze blacksmith, passed away April 2, 2019. A kind man, talented blacksmith and excellent sharpener. He will be missed especially since he had no apprentices and left no one to carry on his work.Mr. Takagi working on his wet grinder in August 2018.Mr. Nakajima’s Forge in Yoita, Nagaoka Japan. Unfortunately it was recently demolished following his retirement.Nakaya Takijiro’s forge, originally made for swords, now dedicated to forging handsaws.
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may fresh boils burst forth on my nose daily.
The gem cannot be polished without friction, nor man perfected without trials.”
Confucius
This post may not be as entertaining as previous ones in this series about sharpening Japanese woodworking tool blades: No swords or artwork or handsome Hollywood philosophers, I’m sorry to say. But with this post we will roll up our sleeves and get some work done.
Many Beloved Customers and Gentle Readers already know most of what is presented in this post, and of them your humble servant begs forgiveness, but it may be that one or two useful gems may be discovered among these scribbles by careful Gentle Readers.
You know the difference between the quality of work a sharp edge performs compared to that of a dull edge. Cuts are clean and finished surfaces are smooth, maybe even shimmering. Your tools are happy, singing and chirping as they cut away. But have you given thought to what a sharp edge really is?
Since the purpose of sharpening is to produce this condition in a blade, a clear understanding is useful, so we will consider the basics in this post.
We shall also examine the naughty cutting edge that seems sharp but suddenly and unexpectedly dulls after just a little use. Would it be useful to know how to detect such a cutting edge before it fails wasting your time and money?
Being in the construction industry, your humble servant would like to begin building this discussion on a firm foundation anchored in bedrock. So let’s get to digging.
The Basics
A cutting tool is essentially a wedge, with two flat sides meeting at an angle. Applying force causes it to wedge apart and sever materials, be it wood, metal, meat or mushrooms.
The geometry of this wedge is critical to its performance. At one extreme, the angle could be 90°. It won’t be sharp, it will be hard to push, and it will crush and tear wood instead of cutting it cleanly, but it will be durable.
At the other extreme, the wedge might be made more acute, say 3°. Such an edge could be made extremely sharp indeed, but it would be too fragile to cut anything but whip cream for long. The point is that the sharp edge is a compromise, acute enough to cut well, but not so acute that cutting pressure and friction will make it dent, roll, wear away, crack or chip easily.
In a woodworking tool his wedge is incorporated into a blade as a beveled edge. In an efficient tool this edge that will be thin enough to cut the intended material well, but at the same time resist dulling for a relatively long time. The words “well” and “long” in the previous sentence are where the magic lies. We will examine these important points in future posts in this series.
Wood Shaving’s Eye View
Ideally, the extreme edge of the ideal metal tool’s extreme cutting should be perfectly smooth and only a single molecule thick. In the real world, cutting edges are rougher and wider, but still manage to cut pretty well.
Examine a sharp cutting edge under a microscope, and you will see imperfections. A dull blade will look even worse of course, showing dents, rips, and even cracks.
The edge created by an 800 grit stoneStill sharp but starting to wearA dulled and dented knife blade
Using a blade wears away and damages the cutting edge rounding and flattening it, destroying the geometry that makes it an effective wedge. Sharpening is the process of (1) restoring the design wedge geometry; and (2) removing defects from the meeting of the wedge’s sides by abrading metal from one or both sides down past any damage, leaving a relatively clean, uniform wedge with minimal defects. This is the sharp edge. It is what the wood experiences. It requires effort to achieve, but it ain’t rocket surgery.
The most difficult part of achieving the two objectives listed above is making nothing from something, in a place that cannot be seen. Now that’s a Zen koan if I ever heard one.
Building confidence in one’s ability to achieve results at the microscopic level is not easy. The key is to understand the goal, and to consistently follow reliable procedures. I will describe those goals and procedures in future posts in this series.
Edge Failure
The ideal cutting edge is uniformly sharp, but few edges in the real world meet these severe criteria at the microscopic level where it matters most. A blade may be sharp in some places, and dull in others. Likewise, a blade may cut well for a while and then dull quickly and suddenly. We have all experienced these irritating failures.
One common cause of these inconsistencies and failures you should be aware of is a cutting edge that is sharp only because it has a defect called a burr. Burrs by themselves can be sharp indeed, but they are thin, irregular, and fragile, and being relatively unsupported by the rest of the blade, can bend, roll over, or break off at the root suddenly and unpredictably creating a nasty dull edge in an instant. A truly sharp edge will not just feel sharp, but will stay sharp for a relatively long time because it is properly shaped and well supported, instead of being only temporarily sharp because of an irregular and fragile burr.
I call burrs a “defect” because they are, but creating a burr is an important step in making a sharp edge. The trick is to continue to refine the wedge after the burr is created until the burr melts away on the stones and the edge is as perfect as we can reasonably expect to make it. Stop the refinement work too soon, or fail to do it completely, and all or part of that unreliable burr may survive to suddenly plop a floater into your punchbowl.
So how does one tell if an edge is properly sharp and free of deceptive burrs without using a scanning electron microscope?
Do you remember ‘Nando’s philosophy described in my previous post? One must reverse the latin lover’s logic. Don’t rely on mahvelous appearance. Don’t rely on bar room stunts like shaving arm hair or telemarketing tricks like cutting strips of paper. Develop skills and train your senses other than eyesight to detect the shape of steel at the microscopic level. This may sound strange but it is possible because your nerve endings are microscopic and can sense the difference between a burr and a truly sharp edge.
I will save the explanation of detailed techniques for a future post, but for now, here are two essential techniques for sensing things too small to see: Use your fingerprints and the exquisitely fine nerves connected to them to detect the presence and size of burrs; Use your fingernails to check the condition of the burr and determine when the blade is ready to move onto the next stone in the sharpening process. Please don’t cut yourself.
In the meantime, let’s have some pleasure before pain. Prepare to be amazed, Ladies and Germs, because in Part 6, coming soon, The Mystery of Steel will unfold before your very eyes! There will be marble relief carvings, bronze statues, oil paintings, gods and demons, death and destruction, and even a pagan soap opera about forbidden love. Oh my! We’re in negotiations for the movie rights now ♫꒰･‿･๑꒱ and need someone to play Vulcan. If anyone knows Spiderman’s agent, please have his people contact my people right away.
YMHOS
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may all my donuts be infested with lawyers.
A few weeks ago I posted an article about seismic dampers used on a high-rise building currently under construction near my office in Marunouchi Tokyo (a 3 minute walk from Tokyo Station). I pass this same jobsite on foot several times a week and take the occasional snapshot. I have other construction sites ongoing, but no high-rise buildings right now, and none that non-disclosure agreements will allow me to share with you. So this is a good opportunity to introduce you to some lesser-known details about major construction work in Tokyo as seen from the sidewalk without risk of offending any clients.
Please notice the gentleman in the orange uniform and big boots in the picture above. I have never met him before, but judging by the color of his uniform, he’s an employee with Obayashi Corporation, one of Japan’s largest and arguably most competent general contractors. I have done a lot of work with this company and respect it a great deal.
Sir Norman Foster, a famous British architect and the designer of Apple’s Campus 2 in Cupertino, California once said that Obayashi Corp is the world’s best general contractor. I tend to agree. And I say this as someone that used to work for two of Obayashi’s competitors in Japan, and who has also worked with many other contractors around the world. If you have visited the Boulder Dam near Las Vegas, Nevada recently, you probably drove over Obayashi’s bridge spanning the gorge.
Anyway, please notice that this erstwhile young man is wearing what looks like a thick coat all puffed up like a marshmallow on a sunny day in mid-August in 37℃ (98°F) temperatures in the shade and 76% relative humidity? Is he loco, Cisco?
Setting aside the somewhat inelegant safety boots (something glittery by Jimmy Choo would suit better methinks) and rolled trouser cuffs that do not help the fashion statement his ensemble is making, you will notice a round white grill on his coat near his elbow. There is an identical grill on the opposite side of the coat you can’t see.
If you haven’t already guessed, the two round grills are actually battery-powered fans pulling outside air into the coat and pushing it out at his collar and wrists cooling our young contractor as he labors diligently in the heat.
A maintenance dude sporting a two-fan cool coat
These “fan coats” are very popular in Japan. They can make a big difference so long as one can perspire adequately. Indeed, these battery-powered garments are credited with saving many construction workers from heat stroke and even death in hot months.
They also come in kiddie sizes and many colors.
Makita makes a “Cordless Fan Jacket” that is sold on Amazon overseas for a lot more than it costs in Japan. Instead of two fans, it has a single fan at the back. I have not used the Makita product and can’t endorse it.
The Makita Cordless Fan Jacket. Notice the high, stiff collar directing moving air over his neck for better cooling, and the fan unit at his back. The cord is leading to the angle grinder he is using, not to the fan.
I hope the weather in your neck of the woods is always balmy with cool breezes in summer so a coat like this is never useful. In the meantime, I’m just waiting for someone to develop sexy-looking steel-toed boots with cooling fans. I wonder what Jimmy Choo will be offering later this year (ツ)
YMHOS
If you have questions or would like to learn more about our tools, please use the questions form located immediately below. Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” Your information will remain confidential (we’re not evil Google or incompetent facebook).
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