Category: Hammers

The Japanese Gennou & Handle Part 1 – Introduction

I do think a carpenter needs a good hammer to bang in the nail.

Oliver Reed

Introduction

This is the first in a series of articles about the Japanese gennou hammer in general (written 玄翁 in Chinese characters and pronounced “gen/noh”) and in particular how to design and make a unique one that perfectly fits your body and style of work.

The objective of these articles is to share with you, Gentle Reader, what your humble servant has learned over the years about gennou handles to help you design and make your own.

I will gladly share the entire series, including the drawings, as a single document with Beloved Customers upon request.

The True Craftsman Makes His Own Tools

A handful of generations ago quality high-carbon steel was difficult to make and expensive, so woodworkers worldwide, especially Japan, could not afford many tools, and the ones they did own or inherit were very important to them.

At least partly to reduce costs, it was standard practice back then for a woodworker (or his master) to commission the metal parts of his tools, such as the heads of his axe, hatchet, adze and hammer, and the blades of his chisels and planes from the local blacksmith. In the United States or other British colonies a craftsman may have purchased chisel and plane blades imported from Sheffield, but he would not want to pay the high costs of shipping wooden components across oceans and over mountains when he could make them himself. After all, woodworking was his business, so a self-respecting craftsman would make all the wooden components of his tools himself as a matter of course. Needless to say, those old boys knew how to make handles.

But things have changed. You may not realize it, but we live in a time of extreme wealth where even the poor live better than kings did 200 years ago, partly due to widespread industrialization making the necessities of life, and even what would have been called luxuries, available to everyone cheaply. This industrialization combined with cheap transportation has resulted in the prevalence of craftsmen purchasing pre-manufactured things, including tool handles.

Accustomed to the easy availability of standard mass-produced tools, lacking a clue about performance and focused like a laser on lowest cost, most woodworkers nowadays get by with colorful but poor quality tools designed by kids using computers working in marketing departments that have never used a handtool professionally, and fabricated by farmers in Chinese factories from higgily-piggily scrap metal. These tools may look great on the internet or wrapped in theft-proof plastic containers hanging on pegs in the big-box retailers, but how do they perform? And how long will they last? And what do they say about the men using them? Tools are terrible gossips, you know.

Gentle Reader cannot purchase a hammer handle like the one we will discuss in this series, and no one can make it for you. A hand-forged gennou head fitted with a handle made in accordance with the guidelines presented in this series will become a unique lifetime tool and the sure sign of a superior craftsman. More importantly, it will help you work more efficiently and precisely, make the joints in your shoulders, arms and hands hurt less, and give you greater confidence in your skills.

If you think this all sounds too good to be true, I challenge you to put it to the test. In fact, there is a series of performance tests listed in the last post of this series (when it is published, see link at the end of this post) that will allow you to generate hard proof of the truth of these claims for yourself. You will be impressed with the results.

While Japanese hammers are the primary focus of this series, you can apply the ergonomic principles and solutions I will describe to all varieties of hammer handles.

Modern Tools: Marketing, Design & Manufacturing

I grew up using hammers designed for maximum sales in a competitive marketplace of amateurs, of the type I call “One Size Fits Nobody.” Back then they were made in the USA, but nowadays they are cheaply mass-produced in China. Prices are rock-bottom, and quality is focused solely on getting an attractive product to the big-box retailers at the right price-point while fending off the slavering hordes of snaggle-tooth lawyers that specialize in product liability and personal injury lawsuits. To these corporations, you and I are beasts in a herd, of no import beyond the contents of our wallets and our willingness to empty them.

Like the cover of a manga comic book, mass-produced modern tools are carefully designed to immediately draw the eye and excite the senses of those passing by. Bright colors and futuristic shapes war with each other for attention on the pegboards of big-box retailers. Handles are made of plastic and rubber fitted over cast steel or molded fiberglass, secured with globs of glue intended to hide malformed ulcerous eyes.

The designers of these blister-makers and nail-benders intend their products to age poorly so they will be discarded by purchasers after just a few years to ensure unending sales of “new-and-improved” replacements. Plastic and rubber are the materials of choice because they are cheap to fabricate, easy to make into colorful, exciting shapes, and speedily surf the spiral wave into the depths of the toilet of planned obsolescence. 

The international playboy that Billy Crystal introduced the world to in “Nando’s Hideaway” might have been talking to one of these hammers when he said “This is from my heart which is deep inside my body: You look mahvelous, absolutely mahvelous dahling. Remember, it is better to look good than to feel good.”

Perhaps these tools do look mahvelous hanging on those pegboards. But how good do they feel?

The tool conglomerate’s product development departments and marketing geniuses have taken the Latin Lover’s philosophy to heart. They know that tools that look good and turn to garbage quickly are more profitable than efficient tools that merely feel good. I am sure ‘Nando would go “crazy nuts” if he observed modern hammers in their natural environment, but alas my friends (saludos, my darlings, you know who you are), Nando will not make the journey to a big-box home center to inspect their pegboard tools because he does not feel good.

Clever people, these marketing strategists, stuffing their pockets with money and landfills with plastic and scrap metal by selling imitation tools to the herd. But as for me, I’ll have none of that churlish fraud, thank you very much.

Would you buy a hammer like this? If so, please don’t call yourself a craftsman or operate heavy equipment.
Wow, a comprehensive torture kit. And just the right color too. Please don’t puke on your computer or smartphone.

Hammer Handle Morphology

The hammer is an extremely simple tool, literally as old as humanity. I suspect humans made the first multi-component tools by attaching wooden handles to stones to make hammers, axes and clubs. 

But despite millennia of history, modern folks have all but forgotten how to make a proper tool handle. It wasn’t always that way.  Everyone made their own replacement handles only five generations ago, and their expectations were guided by sweat and blisters. They didn’t need product development departments in Shanghai to tell them what handle worked best.

Axes are an obvious example of how marketing has morphed handle design. Take a gander at an old tool catalog and notice how axe handles have become thicker in the last 120 years. Do these changes mean that for millennia humans didn’t know how to use axes or make proper handles for them? Do modern human joints and tendons endure the higher vibration and impact forces a thicker, heavier, stiffer handle transmits better than those of our forefathers? Has the nature of modern trees changed such that grain runout no longer weakens a needlessly recurved handle made from their wood?

No, these recent changes in handle design are not intended to make tools more functional or more durable, but are rather to increase sales of cheaply mass-produced tools of apparently innovative design, mediocre quality and disposable utility. They simply look mahvelous, absolutely mahvelous dahling, especially as a picture on a website or hanging on a peg in a hardware store.

Please, don’t get me started on modern mass-market saw handles.

In the next article in this series about beaters we will look at the ergonomics of hammers. Until then, I am profoundly honored to remain,

YMHOS

PS: Here is an excellent article about the “Devolution of Axe Handles” that jives well with my research and experience, and the advice my grandfather gave me about making an axe handle 50+ years ago. And just to prove that we at C&S Tools have refined tastes, here’s some music from Fernando.

The following link is to a folder containing pricelists and photos of most of our products. If you have questions or would like to learn more, please use the form located immediately below titled “Contact Us.”

Please share your insights and comments with everyone by using the form located further below labeled “Leave a Reply.” We aren’t evil Google, facist facebook, thuggish Twitter, or a US Congressman’s Chinese girlfriend and so won’t sell, share, or profitably “misplace” your information. May I never know love or sunshine if I lie.

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Subsequent Posts in The Japanese Gennou & Handle Series

Hammers to Use With Chisels Part 6 – Hammers & Health

A box-stock hardware store gennou hammer. Delicious Ambiguity. A good place to start.

I wanted a perfect ending. Now I’ve learned, the hard way, that some poems don’t rhyme, and some stories don’t have a clear beginning, middle, and end. Life is about not knowing, having to change, taking the moment and making the best of it, without knowing what’s going to happen next. Delicious Ambiguity.

Gilda Radner

In previous posts in this series about hammers to use with C&S Tools’s chisels, we looked at factors such as the type of hammer to use, the sort of face a hammer should have, how much it should weigh, and how to use hammer and chisel as a graceful dance team. In this final post we will look at how hammers can impact our health.

Health Matters

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Swinging a hammer is a violent movement that places large, repetitive impact and vibration stresses on joints, tendons, nerves and muscles. These stresses can make our bodies stronger, or break them down. Carpel tunnel syndrome in office workers clicking away at computer keyboards gets all the attention, but hammers are much more likely to cause health problems. Before nailguns it was common for carpenters to have nerve damage in their hands and arms, but chopping dovetails with a pneumatic chisel is not an option.

When your humble servant was a young apprentice carpenter working in Las Vegas I wanted to be like the older more experienced carpenters on the jobsite that used shiny 32oz waffle-face Vaughn hammers to drive 16d nails through stacked 2×4’s in a single swing (this was before the advent of nailguns and LGS studs). I got where I could do that. I still own that hammer, but like me it is no longer smooth and shiny. I have replaced the wooden handle 3 or 4 times. Would that I could do the same with my knees.

I barely remember him, but he was a young man with lots of energy focused on gaining respect and being productive. Fortunately, I was blessed to work on crews led by older guys with no ego left, whose joints ached (like mine do now), and who just wanted to get as much good work done as efficiently as possible each day until beer-thirty. What I learned from them went beyond wacking nails, and more about actually building things. 

At first I wondered why the bosses would hire old farts when younger guys moved faster and got more work accomplished. What I learned, however, was that, while the old guys did not appear to be as active as the younger carpenters, by the end of the day they had always accomplished more actual work, and with less rework. It was difficult for the young man I was back then to accept, but the bosses new their business, including two important points:

  1. “Fast” and “productive” are not the same thing (the tortoise and the hare principle, “Festina lente“);
  2. Rework takes more than twice the time and money to accomplish than doing the work right the first time.

These two principles are key to being a successful professional woodworker, so a forehead tattoo might help Gentle Reader to remember them. Just a suggestion….

None of those old boys I worked with used extra-long extra-heavy hammers because they knew that productive work required driving nails of different sizes in many different directions (not just straight down or straight forward) more accurately with fewer misses, something a heavy single-purpose framing hammer did not do well. They knew how to avoid wasted motion and time. They knew about rhythm.

They were not what could be called kindly gentlemen, but looking back I prefer to imagine they were looking out for me when they barked “bring more 2×12’s, quick now dammit,” and “stop being a pain in the ass, kid.” Ah yes, good times!

They were prophets too when they warned me that the stresses I placed on my hands, arms, knees and back when I was young and dumb and full of something may not hurt at the time but would hurt every day many years later. It truly pains me to admit it, but those crusty old farts just might have been right.

So in memory of those curmudgeonly carpenters now sorting boards in the big lumberyard in the sky, let me summarize three pieces of profound wisdom they taught me. Do with them as you will. If you still have room, you might want to add them to that forehead tattoo you’ve got going (ツ)。

First, strive to use your hammer efficiently with minimum force, minimum wasted motion, and minimum stress on joints and tendons. Or as the old boys put it: “less swingin more hittin.”

Second, use an efficient hammer of the right type and weight that will get the job done without damaging your joints and tendons.

And third, stop being a pain in the ass.

Just be thankful that I am kinder than those crusty critters were and will tell you clearly in words what they communicated to me only with grunts, curses and boots while chewing on stogies and chortling as they watched me struggle with concrete form-work 18 feet in the air like the proverbial amorous monkey with his football. Yes, love was in the air…

Indeed, just to prove what a sweetheart I am, here are two more pieces of detailed advice specifically related to hammers: First, determine the style of hammer and weight that works best for you and the work situation. This will take experimentation.

Second, make handles for your hammers that suit your body and the combined natural frequency and the work you use them for instead of settling for the usual one-size-fits-nobody hammers hanging like noxious neon-colored plastic fruit on the walls of big-box retailers.

This last point will be the subject of another series of future articles.

That forehead tattoo is down past your chin by now, I suppose. （ツ）

Series Summary

For such a simple subject this series has been rather long. Let me summarize what you should take away:

  1. Use a steel hammer to strike Japanese chisels instead of a mallet made of wood, rawhide, rubber, plastic or brass;
  2. Use a hammer with a flat, polished face to strike your C&S Tool’s chisels for greater work efficiency and increased tool longevity;
  3. Through experimentation, determine and use the hammer weight(s) that best compliments the chisel’s weight and width, the hardness of the wood, and the natural frequency of your hand and arm;
  4. Make a handle for your hammer that follows sound ergonomic principles (versus marketing hype), fits your body, and helps you work with greater speed and precision. This series of posts about designing and making a handle should help;
  5. Less swingin more cuttin;
  6. Cut the wood with a sharp blade instead of beating it to slivers and prying them out with a sharpened screwdriver;
  7. Control your chisel’s depth of cut to prevent your chisel’s cutting edge from binding in the wood, slowing the work down, and becoming dull early;
  8. Do the “chisel cha-cha” but never the “chisel wiggle;” Just don’t.
  9. Don’t use the chisel to lever out jammed-in waste, but instead flick loose waste out of joints with a quick twist of your wrist without slowing down or setting aside chisel or hammer;
  10. Work to a rhythm to maintain your cutting pace and focus.

Thank you for reading this series of articles. Until we meet around the water can next, I have the singular honor to remain,

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 by using 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 my forehead tattoos merge.

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Part 1 – Hammer Varieties

Part 2 – Hammer Faces

Part 3 – Hammer Weight

Part 4 – The Chisel Cha-Cha

Part 5 – Rhythm & Song

Part 6 – Hammers & Health

Hammers to Use With Chisels Part 5 – Rhythm & Song

A masterpiece goban made in 1910 from a single block of wood. Overall height: 29cm (11.4″); 45.2×42.4cm (17.8″square) x thickness: 16.1cm (6.3″). This is the old style goban and a little smaller than modern models.

This life’s hard, but it’s harder if you’re stupid.

George V. Higgins, The Friends of Eddie Coyle

In previous articles in this series about the characteristics of the hammers Beloved Customer should use with C&S Tools’ chisels, we looked at factors such as the type of hammer, the sort of face it should have and how much it should weigh. We even examined ways to use our chisels and hammers as an efficient but dangerous team when cutting mortises, and how to avoid the dreaded chisel wiggle. Your humble servant trusts it was a footloose and gleeful read.

This time your humble servant will delve a little deeper into how to deploy a hammer and chisel team.

The photos above and below are of gameboards, and while gameboards are not really the subject of this post, these photos illustrate an aspect of precise work with chisel and hammer intended not to create a shape to please the eye, but an artistic sound to improve concentration. Perhaps you never have thought about using a chisel to make beautiful sounds, but many of our Beloved Customers that make musical instruments professionally are focused like a laser on this very objective. I hope you will find this little article amusing.

The underside of the same goban. The legs are detachable with short square tenons fitting into loose mortises.
A closeup of hand-carved legs similar to those in the photos above.

Natural Frequency

Much hammer and chisel work performed by professional woodworkers is repetitive with motions repeated thousands of times in a single day, each motion consuming time and energy, hopefully with precision and speed. Are time, energy, precision, and speed important to you? I propose that “Sure and steady wins the race,” sooner and more efficiently than a 2lb steel woodpecker on meth. If these factors matter not to you, then let me know and I will include some colorful bubblewrap in your next order for entertainment purposes.

If you studied pendulums and harmonic motion in physics classes you are aware that every moving object, from watch balances, to buildings, to mountain ranges (yes, mountains wiggle) have a natural “frequency” that defines the vibration of that object when subjected to specific forces. This reliable characteristic is why both mechanical clocks and a quartz crystal timepieces can keep accurate time. Like the pendulum in a grandfather clock, within a certain range of energy input, the longer and heavier an object is, the longer it’s natural frequency is likely to be.

In the case of hammer work this means that a man with a long, heavy arm and hammer combination will naturally swing a hammer cyclically slower than a man with a shorter, lighter arm/hammer combination. That does not mean one is better than the other, it just means that an arm/hammer combination will work most effectively if the assembly’s natural frequency is worked with instead of fought against.

There are several ways to reliably adjust this natural frequency, for instance changing the weight of the hammer/chisel combination, or changing the length of the hammer handle. The closer the hammer’s weight and length are to the ideal for a particular arm/chisel/wood combination the easier it becomes for us to consistently adjust the assembly’s frequency and rhythm of the cutting process while controlling the impact force and thereby the depth of cut.

Rhythm

So let’s say we have the hammer/chisel/wood/arm combination (or saw/wood/arm combination) where we need it to be and we start cutting wood in a repetitive motion. If we keep this motion consistent, like a clock pendulum, we will develop what in music is called “rhythm,” a phenomenon deeply rooted in the human beast. Rhythm is critical to cutting speed and precision. Anything that breaks that rhythm other than the job being completed is counterproductive.

Rhythm has psychological benefits too because it helps us to maintain focus and thereby accomplish more work quicker and more consistently.

But how does one maintain rhythm when cutting mortises? Perhaps you have an internal metronome. If not, it may help to take advantage of an extremely ancient tool called the “work song,” later called the “sea shanty.” These were songs sung by men and women working in groups to coordinate and make more efficient their physical labor, whether planting rice seedlings in flooded fields, pushing wagons over mountains, dragging logs through forests, or pulling soggy ship anchors up from the depths. If the song is in your head instead of just your ear you can easily adjust the song’s rhythm to match the natural frequency of your body and your tools.

I hum a work song when I do repetitive chisel work. I suppose three of my favorites are “What will we do with drunken sailor,” “The Wellerman,” and “Roll the Old Chariot Along.” There are also lots of old plantation and work gang songs that work well. Three modern tunes I find myself humming sometimes are “Señorita,” “Havana” and “Poker Face,” depending on my mood. Here is another, more unusual version by an entertaining German polka band.

While the six songs listed above certainly illustrate the exquisitely refined taste in music your servants at C&S Tools possess in buckets and barrels, there are a few points I need to make. First, the words don’t matter at all. Second, the tune doesn’t matter so long as you like it, it isn’t tedious, and you can adjust the tempo in your mind’s ear to help maintain the rhythm of your chisel work. And third, Spanish-language novellas are best avoided. (ツ）

Just so there’s no confusion, unlike Miss Germanotta, I don’t wear a sequin bikini and white Gestapo hat when I hum Poker Face while sawing wood or chopping scarf joints. If I shaved my legs and trimmed my beard I am confident I would look devastating in such an outfit, but I must refrain for some of my chisels are quite sensitive in matters of decorum. Don’t hate me because I’m beautiful (ツ)。

Summary

The main points I wanted to make in this article can be summarized as follows:

  1. Whether you realize it or not, your chisel, hammer, and body have a natural frequency that you can either work with to your advantage, or fight against;
  2. Using the principles listed in earlier posts in this series you can develop a chisel/hammer combination that balances well with your body, adjusting your natural frequency to improve your productivity and precision;
  3. Develop a rhythm when doing repetitive work that compliments your natural frequency and that helps you maintain both focus and a steady wood-eating pace. Work songs really help. Sequin bikini, Ray Bans, and facial iron mongery are optional.

Well that’s enough German polka music and doggie apparel for now. In the final article in this series we will examine some health matters related to hammers. Y’all come back now, y’hear.

YMHOS

The traditional Japanese roof structure. Notice that no members are subject to tension forces, only compression and bending. Notice also that the bottom of the central beam is finished with just an adze in the classical “naguri” style.

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 by using 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 the sequins fall off my lederhosen!

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Part 1 – Hammer Varieties

Part 2 – Hammer Faces

Part 3 – Hammer Weight

Part 4 – The Chisel Cha-Cha

Part 5 – Rhythm & Song

Part 6 – Hammers & Health

Hammers to Use With Chisels Part 4 – The Chisel Cha-Cha

Your Most Humble and Obedient Servant hard at work. A dab of skin lotion may be called for.
Stan Laurel

You can lead a horse to water, but a pencil must be led.

Stan Laurel

In previous articles in this series about hammers to use with our chisels, your humble servant discussed the varieties of suitable hammers, the appropriate faces on those hammers, and recommended some weight guidelines. In this article we will examine some important hammer and chisel techniques Beloved Customer should consider to make your chisel work more efficient and your chisels last longer

The Chisel Wiggle

Something to keep in mind about our chisels when beating on them is that their cutting edges are intentionally and carefully hand-forged and heat treated by experienced blacksmiths (none with less than 40 years independent experience) to be especially hard to meet the demands of professional craftsmen for the extra sharpness and cutting longevity only hard, fine-grained steel makes possible. They are not the sharpened Chinese screwdrivers sold by the big corporations that amateurs are accustomed to using nowadays.

To maximize the advantage such excellent steel affords, Beloved Customer must avoid driving the chisel so deeply into the wood when cutting mortises, for example, that the extreme cutting edge binds in the wood forcing the user to wiggle the chisel forward and back to loosen and extract it from the cut. I call this undignified movement the “chisel wiggle.”

Your humble servant realizes this is contrary to what many woodworking gurus with their soft-as-butta chisels teach, but I unabashedly assert that it is irresponsible behavior in the case of our professional-grade tools because binding the blade in the wood this way creates what I call a “high pressure cut” situation, placing a tremendous amount of clamping force on the thin metal at the extreme cutting edge. Doing the “chisel wiggle” in this situation will damage the cutting edge dulling it quickly. If you doubt this, please dig out your hand-dandy loupe and do a before-after comparison.

In addition, the time lost extracting the wedged-in-place chisel and the resulting interruption in the workflow caused by repositioning one’s hands, and perhaps even setting aside the hammer (egads!) while doing the chisel wiggle, makes it impossible to maintain an efficient cutting rhythm. If you doubt this, we double-dog dare you to do timed comparative tests. The difference in efficiency will become instantly clear.

People accustomed to using Western chisels with their softer, plasticy blades made from high-alloy high-scrap metal content steel with higgledy piggledy crystalline structure are actively taught to use the chisel like a crowbar to lever waste out of cuts. This is another type of “high-pressure cut” that damages the tool’s cutting edge at the microscopic level.

The mass-produced screwdrivers sold as chisels in the West nowadays are tough but relatively soft, can’t be made that sharp to begin with, and they dull significantly during the first few hammer strikes anyway, so most people can’t detect the edge degradation the chisel wiggle and prying create.

Those who are satisfied with sharpened screwdrivers don’t buy our chisels anyway so I have no advice for those poor benighted souls, only prayers: Namu Amida Butsu. But it is of little matter because they seldom have the sharpening and tool skills required to tell the difference. Horse, meet water; Ah… not thirsty I see.

The Chisel Cha-Cha

Now that we have explained what not to do, let us examine what we should do instead.

Here is wisdom: There are at least three techniques the efficient craftsman should employ, or at least develop skills adequate to deploy, when cutting joints in wood:

  1. Limit the amount of wood included in each cut to an amount easily and quickly cut and easily and quickly removed. Strict control of one’s inner-badger is required;
  2. Stop striking the chisel with hammer during each cut just before the chisel binds in a high-pressure situation, or just before waste clogs the joint. Once again, control of one’s impertinent inner-badger is essential, and the consumption of buckets of methamphetamine is not recommended when performing chisel work.
  3. And then, without changing your grip on its handle, or losing a beat in your cutting rhythm, flick your wrist forwards or backwards so the chisel blade flips the waste out of the joint you are cutting without any silly levering.

And Voila! No time lost extracting a stuck blade or setting down and picking up your hammer and repositioning your grip on the chisel. And the cutting work can continue uninterrupted without the wasted time and effort of extracting a bound chisel all while avoiding a damaged cutting edge.

It’s very much a crisp dance step performed by hammer and chisel with a rhythm something like: “chop, chop, flick, (reposition chisel for next cut)… chop, chop, flick, (reposition chisel for next cut) … chop chop flick.” With each “flick” bits of cleanly cut wood fly out of the joint. I call this series of controlled movements the “ chisel cha cha.”

Next let’s examine the nexus between hammer weight and avoiding the dreaded chisel wiggle.

The Dance of the Hammer and the Chisel

Cha Cha

As mentioned above, the way to avoid the chisel wiggle and instead dance the more efficient and sophisticated chisel cha-cha is to avoid banging the chisel into the cut too deeply/tightly and to limit the waste made with each cut to an easily-removable amount. To dance this dance you need to stop hammering just before the blade binds in the cut, precisely controlling the depth to which your hammer drives your chisel. Easy to say but difficult to accomplish if the hammer is too heavy. On the other hand, too light a hammer is also inefficient. Therefore, there is no one-size-fits-all-situations hammer weight.

A well-balanced, stable hammer with a handle that fits your hand/arm, and of a controllable weight makes it easier to develop and maintain this precise, unconscious control. Lots of factors are involved but the weight of the hammer/chisel combination is the most important one of the bunch.

How to determine the best weight? Of necessity it varies with the chisel, the type of cut being made, the nature of the wood being cut, and the nut holding the hammer so trial and error is the only practical solution. But generally, a hammer that feels a bit on the light side is best. And a good handle makes a world of difference. More on that in future posts, so stay tuned.

Summary

The following summarizes the points you should take away from this series of articles so far.

  1. Select a hammer weight that balances well with the width and weight of the chisel, the hardness of the wood you are cutting, your body, and the type of cuts you are making.
  2. The hammer should not be so heavy that you cannot precisely control the chisel’s depth of cut while maintaining an efficient cutting rhythm close to the natural frequency of the hand/arm/hammer assembly;
  3. Don’t drive the chisel so deeply into the wood that it binds forcing you to wiggle the chisel, or heaven forfend, demands wasteful movements like setting down your hammer to extract it;
  4. Use your sharp chisel for cutting wood, not as a crowbar for levering out waste. Instead, use your sharp blade to quickly cut the waste loose and then remove it from the joint by flicking your wrist without stopping, disrupting your cutting rhythm, or setting down your hammer.

With this, there is nothing to stop you, your hammer, and your chisel from performing as a precise and graceful, but oh so violent team, so shall we dance!

In the next installment in this tale of bold hammers and graceful chisels we will examine in more detail the rhythmical motions involved in doing chisel-work efficiently and the role of the hammer in that dance. Sorry, no champagne or pretty girls but there just might be a song or two. Until then, I have the honor to remain,

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. May my chisel forever wiggle if I lie.

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Hammers to Use With Chisels Part 3 – Hammer Weight

Top: 375gm Yamakichi gennou head by Hiroki with new osage orange handle. Bottom: Ryoguchi-style gennou head by Kosaburo with a seasoned handle of the same osage orange. This same hammer was shown in Part 1 of this series when it was fresh and nuclear-flash yellow. With time and exposure to sunlight the color has changed to this pleasant brown. Thanks Matt for the OO!

“All that is gold does not glitter,

Not all those who wander are lost;

The old that is strong does not wither,

Deep roots are not reached by the frost.

From the ashes a fire shall be woken,

A light from the shadows shall spring;

Renewed shall be blade that was broken,

The crownless again shall be king.

J.R.R. Tolkien, The Fellowship of the Ring

In previous articles in this series about hammers to use with our chisels, your most humble and obedient servant discussed the varieties of hammers and the types of faces suitable for using with our chisels. In this article we will examine not only hammer weights but other factors to help your chisel work go more efficiently.

Beater & Beatee

You can usually tell when a hammer is too light for the job because the chisel or nail isn’t moved much and the beater bounces off. But it’s the other end of the weight scale that causes more serious problems so let’s consider the case of too heavy hammers so we can bracket the Goldilocks weight: Not too heavy, not too light, but just right.

Some people like to use heavy hammers for striking chisels. 2~3-lb ox-killers are good for some jobs, but there are a few things you should consider before defaulting too such a heavy lump.

Is the impact force produced by a heavy hammer really necessary to drive a chisel? Too often not so much. But not everything we do must focus exclusively on efficiency: swinging a hammer is good exercise and it burns calories, something those with excess “ dignity,” such as your humble servant, could use more of. However, in light of other factors discussed below, I urge you to resist the natural compulsion to remain one of the “beautiful people” by maintaining at all costs a sylphlike figure worthy of Paris Fashion Week by obsessively using overly-heavy hammers. Relax, for you already look mahvelous, darling, absolutely mahvelous!

Besides the herculean strength of your mighty arm and the chisel’s durability, Gentle Reader should also consider the durability of your body. Swinging a hammer that is too heavy can over-stress muscles, tendons, bones and joints, stresses that can make workdays long, nights painful and your work sloppy, if not now then certainly as you age. More on that subject in a future article.

But if the weight of the head is a good balance with the work you are doing, and you have a good handle on your hammer or gennou, things just go better. We will look at this more in the final post in this series.

Let’s start at the beginning and consider the movement of the hammer and the forces generated when accelerating it towards nail or chisel and the resulting stresses produced in muscles, tendons, bones and joints. Obviously, it is wise to keep these stresses within acceptable limits, especially if you need to repeat this movement hundreds or even thousands of times in a day. It should likewise be obvious that a hammer that is overly heavy makes limiting these stresses difficult.

Now that we have the hammer moving, let’s examine what happens when it stops as it strikes nail or chisel. Is wacking the nail or chisel as hard as possible the goal, or is the goal to drive the nail into the wood the right depth, or to motivate the chisel to cut wood an appropriate distance? If the latter, then there is a practical limit to the impact force required.

In other words, does driving a nail so deeply the wood is damaged unnecessarily, or does wacking a chisel so hard it cuts all the way through the board, or even binds in the wood, help us do better work?

Are the excessive stresses and vibrations flowing and slamming through one’s joints and tendons as a result of the violent acceleration, deceleration and impact forces generated when swinging an overweight hammer healthy and helpful? Or do they just waste energy, damage our work product, cause bruising, pinching, grinding and numbness and generally wear out hands and arms? Do these excessive stresses and vibrations improve our precision?

The positive and negative results of using a hammer are easier to control if the hammer’s weight is balanced with our bodies, the nail or chisel, and the wood.

Another factor to consider is the nature of the beatee. Nails often suffer from hammer abuse, but they don’t have feelings or form mutual support groups with monthly meetings and free coffee and donuts, while chisels do, so I encourage you be sensitive to your chisel’s needs when selecting a hammer weight. Oh, and don’t forget to donate a box of fresh donuts occasionally (with sprinkles).

Our chisels are hand-made professional-grade tools intended to be used by craftsmen who demand the extra sharpness and cutting longevity only hard, fine-grained steel makes possible. Therefore they are not as tough as the soft, sharpened Chinese screwdrivers sold by the big corporations as chisels that amateurs are accustomed to nowadays. Accordingly you should select a hammer weight that won’t damage the blades or splinter the handles of your fine chisels even if you must use them all day for days on end hard enough for the impact forces to make the handles hot. You may be as strong as John Henry, but a 2-lb hammer will destroy most any chisel given time and determination.

Weighty Matters

Of course, the harder the wood, the deeper the cut, the wider and heavier the chisel, the heavier the hammer needed. But what is an efficient hammer weight? Let’s consider some guidelines.

Oiirenomi & Mukomachinomi Chisels

For most commercially-available woods you are likely to cut with your oiirenomi chisels or mukomachinomi (mortise chisel), 260gm/9oz/70monme is a good place to start when using narrower width chisels 18mm and less.

300gm (10.5oz/80monme) to 375gm (14oz/100monme) is probably good for wider chisels. BTW the standard carpenter’s hammer in Japan weighs between 375gm (14oz/100monme) to 450gm (16oz/120monme), but this is too heavy for most precision work using oiirenomi in furniture, cabinets, and joinery work.

Atsunomi Chisels

For the heavier atsunomi chisels from 18mm to 24mm in width, 375gm (14oz/100monme) ~ 450gm (16oz/120monme) is usually a good weight.

For wider atsunomi chisels, 675gm (24oz/180monme) to 750gm (26oz/200monme) is good. Maybe as heavy as 937gm (32oz/250monme) for motivating wide 48-54mm chisels when cutting hard woods if you have experience, strong wrists, and speed is not important. Yes, within limits and with a good handle, lighter weight hammers tend to accomplish more work quicker.

As Captain Barbossa explained the Pirate’s Code, these are “more what you’d call “guidelines” than actual rules.”

In future posts in this series we will examine factors such as how to use hammers and chisels efficiently, and how to avoid injuries.

Until then, I have the honor to remain,

YMHOS

PS: We have also published another series of articles about making a handle for your hammer that fits your body and will work most efficiently for you, beginning HERE. So let’s talk some more soon.

Harrrrg. Your hammer’s how heavy?!

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 fingers become beatees.

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Hammers to Use With Chisels Part 2 – Hammer Faces

The Jabberwock! Not just a beautiful face.

Beware the Jabberwock, my son!
      The jaws that bite, the claws that catch!
Beware the Jubjub bird, and shun
      The frumious Bandersnatch!

Lewis Carroll

This is the second post in our six-part series about hammers to use with our chisels. As with all the tool-related articles we publish, this one is based on past communications with, and in response to direct questions from, our Beloved Customers. Your humble servant hopes that not only Beloved Customers (may the hair on their toes never fall out) but Gentle Readers too may gain something from these articles.

We sell limited quantities of hand-forged professional-grade chisels to professionals who use them to please their customers and feed their families.

We are tickled pink when amateurs purchase our products, but our target customer is the experienced professional woodworker. If you do your part our chisels will provide faithful, reliable service until, after many decades, nothing is left of the blade but a nub. But to achieve this longevity, and to avoid smiles turning upside down, we insist Beloved Customers use flat-faced hammers to motivate our chisels as a condition of our warranty. It’s that important, at least for the professional that uses his chisel even after the blade and handle become hot.

375gm gennou by Kosaburo with a black Persimmon handle resting on a Go board. The head is a classical style seldom seen nowadays.

In the previous post in this series we looked at the Japanese gennou hammer with its two faces: one domed and the other flat. In this post we will examine these two styles of hammer faces in more detail. We will leave waffle-faces to the Belgians for now.

The Domed Hammer Face

Few people in industrialized countries outside of Japan have any experience with flat-faced hammers since manufacturers automatically grind a convex or domed striking face on their hammers nowadays. It’s simply what consumers are accustomed too. But I daresay few have ever considered the ramifications of the dome.

Does the domed face on this standard 16oz American finish hammer look centered to you? Does it look smooth?

A domed face on a hammer has some advantages, of course. For instance, when one needs to “set” a nail with its head just below the flat surface of the piece of wood into which the nail is driven. But does a domed face help the hammer drive nails faster or straighter? Does it help reduce the ratio of bent nails to straight nails? Does it motivate chisels more efficiently? No, no and no.

Another more questionable feature of the domed face (depending on your viewpoint) is that it makes it difficult to judge the accuracy of one’s alignment of the centerpoint of the domed face and with the centerline of the hammer head. Who, pray tell, profits from this ambivalent construction? I’ll give you one guess, and it ain’t me or thee.

Indeed, if your working hammer tends to bend a lot of nails, I recommend you carefully examine its face with a square for centricity and uniformity. “Doh! (palm to forehead). No frikin wonder,” may well be your genteel reaction.

While it may seem passing strange, we strongly recommend Beloved Customers use a hammer with a flat striking face to motivate our oiirenomi chisels, atsunomi chisels, and mortise chisels.

So why is a domed-face hammer a problem when striking Japanese chisels? Simply because it tends to focus the impact forces on a relatively smaller area on the wooden handle than a flat-faced hammer does accelerating wear on, and shortening the life of, the handle.

In addition, and especially if you are skilled at hitting the handle dead-center a high percentage of the time, a domed face will actually encourage the mild-steel crown to try to jump off the handle whereupon the steel hammer gleefully beats the crown and deforms it, often to the point where the deformed crown itself may damage the handle. Yes, this takes some time, but it happens frequently, a wasteful tragedy that can be avoided by using a hammer with a flat face and some simple setup procedures.

The Flat Hammer Face

While your humble servant is inordinately fond of the Japanese gennou hammer, it is by no means the only viable option. Indeed, you can easily modify most any decent-quality, properly-hardened hammer to have a flat face by simply abrading it with a grinder or sander.

Be sure you make the new face planar (flat) and truly square to the hammer’s centerline because a tilt to the left or right will make doing precise work inexplicably difficult and may lead to insanity. I once knew a “frugal” carpenter (read “cheap jackass”) who insisted on using a hammer with a skewampus face. The cumulative corrosion to his confidence caused his wits to wander into the weeds (iambic pentameter?). A sad story but one, I am told, that is commonly heard at AA meetings.

If you are modifying a standard hammer with a standard handle, you may benefit from tilting the face’s plane a bit inwards towards the handle, but there is not adequate space in this post to discuss this modification in detail.

Whatever you do, be especially careful to avoid overheating the hammer’s face while grinding/sanding it; Too hot and the temper will be damaged softening the hammer’s face and ruining it. Seriously. Even a wooden chisel handle will eventually mushroom a steel hammer that has lost its temper.

Here’s a guideline: If the hammer’s face becomes too hot to touch with your bare finger, its temper is at serious risk.

Finally, once the face is as flat and square and smooth as you can make it with your grinder or sander, be sure to polish the face because a smooth face wears out the chisel handle slower. A final polish with 320 grit W/D sandpaper is adequate. We polish ours even finer on sharpening stones. Overkill? Yup. Why bother? Because we like purty hammers and they deserve our love. Don’t worry, the polish won’t make the hammer’s face slippery, unless you imitate Mr. March Hare and spread butter on it.

By the way, once your flat-face hammer is ready, try driving nails with it. You will find it works a lot better for everything except setting nailheads below the board’s face. A nailset works better for that job anyway.

We hope our Beloved Customers will take this article to heart for the sake of their chisels.

Summary

In this post we reviewed two types of hammer faces: domed and flat. We also considered the advantages and disadvantages of each, and explained why a flat face is best for beating on Japanese chisels, and gave an example of the brutish damage a domed face can inflict on a poor innocent chisel. Like me, some of you may have shed a tear at the sight, but I bid you take heart because we also instructed you in how to convert a common domed-face hammer of any sort to a more genteel, polished, flat-faced hammer at no cost, one that will also drive nails better without butter. O frabjous day! Callooh! Callay!

To motivate chisels efficiently, the hammer must not only have a flat face, but it must be of the appropriate weight. Of course, the harder the wood, the deeper the cut, the wider and heavier the chisel, the heavier the hammer needed. But what is an efficient hammer weight? We will examine some options in the next post in this series. Please stay tuned, my beamish boy.

Until then, I have the honor to remain,

YMHOS

A hand-forged square gennou head by Hiroki with a handle made from a traditional Japanese handle wood called “Kamatsu” (Pourthiaea villosa) meaning “sickle handle, also called “Ushikoroshi (“cow killer”). Despite the appearance, the head is one-piece of uniform steel, not a jigane body with forge-welded steel faces. BTW, if someone tells you that hammers with forge-welded faces are superior, direct them to the closest legal marijuana dispensary so they can maintain their waking psychotic dreams.

If you have questions or would like to learn more about our tools, please click the see 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 a Bandersnatch fruminate all over my face!

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Hammers to Use With Chisels Part 1 – Hammer Varieties

A modern-style 750gm gennou head hand-forged by Kosaburo, hung with a black persimmon handle. I purchased this high-quality head over 33 years ago. An heirloom tool and a good buddy.

Yet such is oft the course of deeds that move the wheels of the world: small hands do them because they must, while the eyes of the great are elsewhere.

Elrond

This is the first article in a six-part series that condenses the advice your humble servant has given to our Beloved Customers over the years regarding the hammers they should use with our chisels. While some of this information is relevant to our warranty, all of it is relevant to how well our chisels will perform and the pleasure Beloved Customers will enjoy using them.

In this first part we will focus on the varieties of hammers we recommend. Subsequent articles in this series will focus on appropriate hammer weights and faces, how to use a chisel efficiently, the “chisel cha-cha,” the importance of rhythm, as well as a discussion about health and hammers. There may even be a song or two to hum along with. Helluvalot better than a performance of Cats, and cheaper too!

In the future we will present several different series, one with more details about hammer heads, and another explaining why and describing how to make a handle for a Japanese gennou hammer (or any hammer for that matter), with scaled reference drawings. We will of course provide the entire contents of these articles wrapped up in a happy wiggling bundle to Beloved Customers that purchase one of our gennou heads. Yes, there are more perks to being a Beloved Customer than simple toe-curling joy (ツ）。As Blackadder’s little buddy Baldrick often said: ” I have a cunning plan.”

Hammer Materials

30mm Atsunomi by Kiyotada

We sell tatakinomi chisels such as oiirenomi, hantataki chisels, mukomachinomi (mortise chisels), or atsunomi all designed to be motivated by the most efficient method available, namely a steel hammer swung by human hand and arm. I won’t debate the pros/cons of steel hammers versus wooden mallets versus plastic mallets versus brass hammers in this post because the physics are as obvious as a lemur in a lingerie shop (they’re a bit hairy, they jump and climb all over the displays and bra straps are forever slipping off their skinny shoulders, but not in a seductive manner!) beyond noting that a hardened steel hammer imparts more energy to a chisel in a more easily focused and controllable manner than any other type of beater. Some may disagree; A mind is a terrible thing to taste.

Occasionally Gentle Readers, and sometimes even Beloved Customers, ask if it’s OK to use a mallet of wood or plastic. Of course, it’s entirely acceptable, but no more necessary in the case of our professional-grade chisels than a speed governor set at 45mph is in a Ferrari.

The advantages of using a steel hammer to motivate chisels are quite obvious, even without doing energy calculations, but are there any disadvantages? Mochiron (Japanese for “of course”).

Steel hammers can concentrate so much energy on a tool handle so efficiently and so quickly that they routinely destroy the handles of the sharpened screwdrivers sold as chisels nowadays in Western countries due to faulty handle design.

At this point, wise Gentle Reader will ask themself why the handles of modern chisels are so fragile. Is it just an accident? If intentional, is modern wood softer and easier to cut than wood a few hundred years ago? Or has modern man become demented forgetting all the lessons of the past regarding chisel design, just as some have forgotten what the word “woman” means?

While dementia, sexual perversion and corruption among the leaders of the nations is obviously a serious problem nowadays, it is likely many marketing gurus, e-commerce pukes and cad operators never learned much about the tools they manufacture and sell. It’s also as obvious as lingerie on a lemur that most modern chisels are designed not to provide good service but rather to maximize profits through: (1) Lowest possible manufacturing costs; (2) Attractive appearance while hanging on hooks in the hardware store; and (3) Future purchases to replace chisels with broken handles, in other words, a cheap, eye-catching product incorporating planned obsolescence.

Prosimians flouncing around in lacy unmentionables aside, the tataki nomi chisels we sell are professional-grade tools designed to be struck by hardened-steel flat-faced hammers all day long and need not be coddled. They have tough Japanese oak handles protected by a cleverly-designed mild-steel kuchigane (coned ferrule) fitted where the handle meets the blade, and a mild-steel hoop, or crown, seated at the butt end of the handle, so they will not split or break when setup and used properly.

We have provided clear instructions for how to perform this setup job here.

But there is more to hammers than just materials, so let’s continue onto the next subject.

Japanese Hammer Types

A Kosaburo head with a brand-new nuclear-flash colored Osage Orange handle

The traditional hammer used in Eastern Japan for striking chisels and general carpentry work is called a “gennou” pronounced “ghen/noh.”

The gennou common to Eastern Japan is a simple symmetrical cylinder of one sort or another with a flat face on one end and a domed face on the other, often called the “ryoguchi gennou.” No claws, no pointy tail. The flat face is used for striking chisels and pounding nails. The domed face is used for something called “kigoroshi” and for the last stroke when setting nails. It’s a handy tool and more stable in the swing than a claw hammer. It’s just a matter of physics.

Japanese carpenters use a specialized nail bar for pulling nails effectively increasing the lifespan of their hammer handles, so claws are not necessary.

3 gennou heads. The far left head is a simple economy head. The center head is a higher-grade head slightly flared towards the ends. The far right head is an entirely hand-forged classic head by Kosaburo.

The Yamakichi style gennou head (see photo below) is another variety popular primarily in Western Japan. The tail is not pointy but tapers to a small square face that is useful for starting small nails and for “ tapping out” plane blades. The striking face typically has a slight curvature which is helpful for setting nails, but not enough to damage a chisel. The moment of inertia is less than the symmetrical gennou head so it is not as stable in the swing, but it is still a fine head and very sexy looking.

A “Yamakichi” style head by Hiroki with a mellowed Osage Orange handle

The pictures below are of a gennou head called “Funate,” which translates to “boat hand.” I have heard it originated with ship carpenters, but am uncertain. The tail end is a small square as you can see from the photo, and is handy for setting nails. It makes a great finish hammer, but as a hammer for striking gennou it never appealed to me. But there are plenty of craftsmen that love this hammer.

a Funate gennou with a bubinga handle

Any of these hammers will do the job: it’s all personal preference.

Western Hammer Types

The purpose of this article is is not to suggest that Beloved Customers must use a Japanese gennou hammer when beating on our chisels. In fact, nearly any variety of quality steel hammer can be easily modified to do the job more-or-less satisfactorily, including claw hammers, engineer’s hammers, warrington hammers, or even ball peen hammers, so it isn’t necessary to buy a special hammer. In fact, we’ll discuss those modifications in detail as well as the relevant physics of hammers in future articles in this series. Rejoice for there will be formulas!

In the next post in this series we will examine the type of face a hammer used to strike our chisels should have. Please come back and bring your fuzzy primate friends.

YMHOS

Do you have something extra-slinky with red Chantilly lace trim?

If you have questions or would like to learn more about our tools, please click the see 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 my nose grow to the size of a watermelon.

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