Japanese Handplanes – Part 4: Fitting Blade & Body

After tumbling down the rabbit hole, Alice discusses her options with her new friends Gryphon and Mock Turtle. After perusing this article, I hope Gentle Readers will be less discombobulated than poor Alice, less tearful than Dear Mock Turtle, and less indignant than Noble Gryphon.

A Bruise Is A Lesson… And Each Lesson Makes Us Better.

George R.R. Martin, Syrio Forel, Game of Thrones,

In this the fourth post in our series about the Japanese hiraganna handplane we will discuss how to fit the plane’s wooden body to the blade thereby improving the tool’s performance.

As is the case for most of the posts in this blog, this one too is intended primarily for the information and entertainment of our Beloved Customers, but all well-behaved Gentle Readers are welcome to partake. Bon apetit.

Why Fit Body to Blade?

Beloved Customers may wonder why your humble servant is inflicting the internet with another pointless article about Japanese planes, especially since the handplanes purveyed by C&S Tools are advertised as “ready to use” when new. Let’s address this absolutely valid concern.

As mentioned in the Part 3 of the Japanese Handplane Series, Mr. Inomoto, the daiuchi shokunin that cuts the bodies from Japanese White Oak to fit the blades forged and sharpened by Mr. Nakano, does indeed do more than just cut a gap for a blade to slot into, but fits the blade to the body so it is able to cut a decent shaving before it leaves his workshop. However, due to cost considerations and practical limits to his prophetic talents and clairvoyant insights regarding who will eventually own each plane and their preferences for the blade-body marriage, he fits the blade on the tight side, assuming the end-user will adjust the body to best suit his own purposes. Ergo the paragraph titled “Plane Philosophy” in Part 3.

I suspect relatively few Beloved Customers have given the subject serious thought, but it is nonetheless true that each owner of a Japanese plane must develop their own philosophy regarding the relationship between blade and body, and if they deem it necessary, adjust their plane body accordingly.

This article assumes Beloved Customer has decided to refine the fit between blade and body, and instructs in how to make those refinements. Are they absolutely necessary? Nah. Will they make a difference? Yes, but the degree of improvement obtained will vary from plane to plane and person to person.

Nonetheless, your humble servant recommends Beloved Customers, especially those interested in obtaining professional-level plane maintenance and usage skills, to perform the operations described in this and future articles in this series. You’ll be glad you did even if it may take some years for the benefits obtained to become evident.

So with that out of the way, let’s assemble the tools we will need to make some righteous sawdust.

Tools

The following is a list of tools recommended for this job.

  1. Wooden mallet for striking the blade and body;
  2. Carpenter’s pencil and/or marking pen;
  3. Masking tape to protect the wooden body from oily fingerprints;
  4. Vernier caliper and/or divider for measuring and comparing;
  5. Various chisels (e.g. 3mm, 6mm, 9mm usunomi paring chisels);
  6. Metal file (to be modified) or a 15~18mm wide chisel (to be modified).
The tools needed for fitting the body to the blade. The chisel next to the vernier caliper is an old Sorby chisel modified especially for working on plane beds and gifted to me by Chris Vandiver. Thanks, Chris.

Regarding the modified file or chisel listed above, this is a push scraper, an ancient tool once commonly used for precision metalwork. Your humble servant uses it to shave the bed to fit the blade. You can make this tool as wide as you wish, but please note that if the blade of either file or chisel is too wide, your shaving efforts may not produce smooth results.

You can easily make this scraping tool from a chisel or an old file by grinding a flat on the end of the file or cutting edge of the chisel square to the centerline of the blade and at an 80~90˚bevel angle. Then hone this square cutting edge and at least one of the two adjoining surfaces to 1000 grit. Voila.

If you use a file you will want to attach a handle to its tang to avoid getting red sticky stuff on your pretty wood.

If you prefer to use a regular chisel, that’s OK too, but you will find this scraper does a cleaner job with less effort.

Blade Preparation

This explanation assumes the blade is sharp and the ura is in good shape. If not, please sharpen the blade because it will of course affect the fit of blade to body.

While you are at it, check that the side edges of the blade are free of burrs or rough grinder marks which might abrade the grooves after some use. Some grinder marks may be unavoidable, but if the sides feel rough and abrasive to the back of your hand, smooth the edges a little using a sander and/or sharpening stones.

In addition, please make sure the right and left clipped corners of the blade’s cutting edge, called “ears,” are properly trimmed, meaning that they are ground large enough to reduce the width of the sharp cutting edge so it fills the width of the plane’s mouth but does not extend into the grooves, because if it does get into the grooves, shavings will become jammed between the blade and groove wasting your energy and leaving nasty scuff marks and sometimes even tracks on the planed surface. それは困る.

When sharpening a plane blade, therefore, it is important to check and trim these ears periodically. A few passes on a diamond plate or rough stone will do the job; It doesn’t need to be pretty, and the ears don’t need to be sharpened because they will never touch the surfaces to be planed.

The disassembled plane used as an example in this article, a 70mm finish plane with a Blue-label steel blade hand-forged by Mr. Nakano Takeo and a Japanese White Oak body by Mr. Inomoto Isao. An excellent tool.

Checking & Tuning the Mouth

Beloved Customers won’t need to worry about this, but Gentle Readers fettling plane bodies made by themselves or others should be careful the first time they adjust the blade’s cutting edge to project through the mouth to ensure there is adequate clearance because if the mouth isn’t wide enough to allow the cutting edge to pass through cleanly with a little clearance to spare, the blade may chip out the sole.

If there is any question about the mouth/blade clearance, the first time you extend the blade through the mouth, press the plane sole-down on a piece of clean wood while tapping the head of the blade with your mallet to make a zero clearance cut at the mouth. The supporting board will prevent the mouth from chipping. This is also standard practice when opening the mouth of a new plane body.

Hold the plane up to a light and peer through the mouth to observe the gap between cutting edge and body. The width of this gap must be greater than zero, but how wide it needs to be will depend on the thickness of the shaving you intend to cut.

Ugly tear-out can be minimized and the polish of the planed surface increased by having a tight mouth. Indeed, the tightness of the mouth and the area of the sole directly in front of the mouth applying uniform pressure on the wooden surface being planed up to the last .001 millimeter in front of the mouth is critical for exceptionally fine tear out- free cuts. On the other hand a mouth gap that is too narrow to pass the intended thickness of shaving will jamb every time, so the user must balance the width of the mouth, the desired shaving thickness, and blade projection to obtain good results.

Here is wisdom: repeatedly jamming packed chips and shavings into the mouth is not only hard on the blade, but it will damage the mouth, so before this happens too many times, you want to either adjust the mouth or your expectations for shaving thickness.

To open up or adjust the mouth, cut a hardwood guide block to use with a chisel to pare the mouth opening, and clamp it to the sole. The angle of the block will vary with the angle of the blade.

Then using an exceptionally sharp paring chisel and this guide block, take minute shavings at the mouth using skewed strokes. A paring chisel with a three-hollow mitsuura ura is ideal for this task, but any sharp chisel with a longish blade will do the job.

Body Protection

This process will involve graphite pencils, marking pen ink and fingers, so to keep the wooden body from looking dirty, please cover the top and sides with a low-tack masking tape. In this example, I used a pretty pink tape.

Adjusting the Blade to the Mouth

As mentioned above, the blade fits into and is clamped in-place by the two tapered grooves cut into the body. Sometimes the fit between the side edges of the blade and the bottom of these grooves is too tight. This can occur in a new plane if the body was improperly cut to begin with, but the most common cause is shrinkage of the body due to humidity changes.

Of course, the wooden body will change dimensions with changes in ambient humidity, while the blade won’t. If a plane is shipped from a wet climate like Japan (at some times of the year) to a dry climate like the Mojave Desert (all times of the year), for example, the body may shrink in width developing tremendous pressure on the side edges of the blade, sometimes enough to crack or split the body. Therefore, if you are located in a dry climate and acquire a plane from a wetter climate, it may be wise to remove the blade and let the body acclimatize for a week or so.

As mentioned above, the blade is tapered in width, being wider at the head and narrowest near the cutting edge. This is intentional. Ideally, you want the side edges of the blade to just kiss the bottom of the grooves where they exit the top surface of the body, and not touch the bottom of the grooves anywhere else. This type of fit will to make it easy to make minute right or left adjustments to the cutting edge’s projection by tapping the head of the blade right or left.

Obviously (and this is an important point to understand), if both of the blade’s side edges are in close contact with the bottom of the grooves their full-length, this important method of adjustment will no bueno.

Use you vernier caliper or divider to check that the the blade does indeed become narrower in width from the point where it exits the grooves at the top surface of the body and the point where the cutting bevel begins. If it doesn’t, you will need to grind in some taper. How much? Mr. Nakano’s blades typically taper the amounts shown in the photos above, but they are handmade and each one is little different.

The distance measured between the blade grooves where the blade makes contact at the top of the grooves. Please notice that this distance is slightly greater than the width of the blade at this point as shown in the photo on the right above.

In any case, please ensure the body provides adequate clearance to just accommodate the blade’s width. Mark 1 Eyeball is often good enough for this task, but a divider is better and a vernier caliper is ideal.

Make a final check by applying marking pen ink to the sides of the blade 1cm down from where the blade would normally exit the grooves at the top surface of the body. More ink is not necessary.

If some paring of the grooves is necessary to provide adequate clearance, please remove no more wood than is absolutely necessary.

Groove Maintenance

A common problem we see with old planes is cracked and split bodies caused by the tapered blade becoming shorter over the years due to repeated sharpenings, and therefore the edges of the blade exerting excessive pressure on the bottom of the grooves when a careless user mercilessly pounds the blade into the body. This sort of damage is entirely avoidable by humans, but some gorillas advocate paring the bottom of the grooves of new planes to create a gap of 2~2.5mm between the groove and blade to accommodate all the reduction in length the blade may experience over many years of service at once. To this practice, your most humble and obedient servant can only respond “Poppycock!”

Why do I object to what seems to be a logical solution? Glad you asked.

If you chisel out a big gap between the side edges of the blade and bottom of the groove, not only will you unnecessarily weaken the body by severing continuous wood fibers at the narrowest, weakest, most critical point of the body (think about it real frikin hard), but the pivoting action required to adjust the blade’s projection right and left by tapping the head right and left will become more difficult, while at the same time the blade will become less stable in the body.

I write this based on bitter experience obtained from following bad advice received before I knew better, and later being mocked by more experienced craftsmen who noticed my silly error. An embarrassing episode indeed.

Beloved Customers will of course have purchased a high-quality plane from C&S Tools, with a blade hand-forged by Mr. Nakano Takeo and Japanese White Oak body cut by Mr. Inomoto Isao, but just in case you are working on a lower-grade tool, here are some things you need to check.

The way to avoid body damage due to shrinkage of body or blade is simple: (1) Pay attention to the fit of the blade in the grooves; (3) Adjust the clearance when appropriate, and; (3) Avoid excessive use of recreational mushrooms which may dull the senses and cause chronic tool neglect.

In other words, when you notice the blade becoming tight in the grooves, simply pare the bottom of the grooves a nat’s mustache hair deeper. Don’t get carried away because a little contact is a good thing!

Our 6mm and 3mm usunomi paring chisels are ideal for this job. but standard oiirenomi chisels can accomplish the task too.

Another option is to grind the sides of the blade making the blade a little narrower in width.

Beloved Customers have the choice of learning from your humble servant’s stupid mistakes or from their own. Of course, I suppose there’s always the default option too many lost and wandering souls select of neglecting to learn anything at all…

Fitting the Bed to the Blade’s Back

Assuming Beloved Customer has completed the checks and adjustments in the previous sections, the general steps for fitting the bed to the blade are as follows:

  1. Begin by rubbing the back of the blade from where the cutting bevel begins to the end of the steel lamination with your carpenter’s pencil giving it decent coat of graphite. Marking pen ink or Dykem works too.
  2. Insert the blade into the grooves and tap it with your mallet (not a metal hammer!) until the cutting edge is nearly projecting from the mouth. You may need to really wack the blade hard 5~10 times to accomplish this the first time.
  3. Next remove the blade by holding the plane in your hand and alternating strikes on the right and left sides of the chamfer on the body behind the blade’s head. Don’t strike the flat end of the body! The blade should wiggle out after some less-than-gentle persuasion. If your plane doesn’t already have a pretty 6~8mm wide chamfer cut on this edge, please make one.
  4. Examine the bed. You will notice how the areas in contact with the blade are now marked with graphite. We need to pare or scrape down these contact points to achieve a more uniform contact.
  5. Use your chisel or scraper tool to carefully shave down the high spots marked with graphite. Cut/scrape only those areas marked with graphite. Before you begin making sawdust, however, please be careful to not remove any wood from any of the three surfaces inside each side groove for now. You need to sneak up on the final shape of the bed like a kitten stalking a grasshopper, with eyes wide open, gently and a little bit at a time. It would be a serious mistake to try to make a perfect fit after only a few passes.
  6. Repeat steps 2~5. You may need to do this dance 10 times to get it right. You won’t need to apply more graphite each time, just rub the back with a piece of cloth to redistribute the graphite. Or you can use your carpenter’s pencil again. With each iteration, the graphite marks left on the bed will increase in number and become larger. You want to be able to seat the plane blade with only three or four medium strikes with your mallet, and make fine adjustments with just a few more. At no time should your plane squeal a complaint.
  7. When the blade can be easily seated with 3 or four medium wacks of your mallet, use a metal file to lightly smooth out the rest of the bed. Perfection is neither attainable nor should it be sought.
The bed before applying graphite and any shaving. Mr. Inomoto Isao does a nice job, so contact is good, but still tighter than I prefer. The No.13 is a mark he made to keep blade and body matched. Notice the “tsutsumi” shelf cut at the bed just inside the mouth. This is a nice, pretty detail that aids in preventing the blade from “sniping” the ends of narrow boards, but sometimes it gets in the way, and after much use, it becomes so thin it must be removed. It is neither necessary nor sacred.
The back of the blade has been rubbed with a graphite pencil, and is being tapped into the body. It takes some forceful strikes to get it into position. Notice the purty-pink low-tack masking tape applied to the body to help keep it free of graphite fingerprints. My planes seem to appreciate brighter, feminine colors.
Graphite marks left on the bed from the first insertion of the blade. Not terrible, but contact could be better.
Shaving the bed with a scraper chisel the first time
Shaving the bed with a scraper chisel the second time
The bed after shaving it the third time.
The completed bed following final cleanup with a file. The blade can be inserted with three medium mallet strikes, and fine adjustments made in 3~4 strikes. The blade does not tend to twist out of alignment. Notice the graphite marks left on the tsutsumi shelf where the blade has contacted it.

The Peppermint Twist

Now that the bed is fitted to the blade, we need to return our attention to the grooves.

If one groove is pinching the blade more than the other, the blade will want to twist out of alignment. This can be very irritating.

The surfaces inside the grooves touching the ura and back of the blade should be clean and straight. In any case, unless it causes a serious performance problem, it’s best to leave these surfaces alone for a while because after inserting and removing the blade several times the fit may improve automatically.

If the blade continues to twist out of alignment, however, determine where the high points are on the surface of the groove touching the blade’s ura. You can do this by peering into and through the mouth while shining a light into the groove.

Once you have identified the high spot(s) glue a piece of fine sandpaper to a thin stick of wood and sand it down a little bit at a time between inserting and removing the blade frequently to check the fit.

Don’t sand down the surface inside the groove which contacts the blade’s back unless absolutely necessary because this will effectively open up the mouth, something we want to avoid for as long as possible.

With this, your plane’s hard, sharp blade and soft wooden body should fit together like hand in glove. It may sound like a lot of work, but it usually isn’t. In fact, besides prepping the blade, the whole process can usually be completed in less time than it takes to read about it.

So far in this series I have provided a lot more detail and explanation than I have ever seen in writing elsewhere. It took me many years of fumbling in the dark, much consultation with older, more experienced craftsmen, no few curses and ungentle slaps to the back of the head, and numerous expensive mistakes to learn these things. I hope Beloved Customers profit from them.

In the next post in this ongoing adventure towards the perfect Japanese handplane we will shift our attention to fitting the chipbreaker (uragane 裏金) to the blade.

See you again soon.

YMHOS

Alice asking advice of a caterpillar sitting on a magic mushroom, smoking magic mushroom.

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 ears of all my plane blades become clogged with wax.

Other Posts in the Japanese Handplane Series:

Japanese Handplanes – Part 3: The Blade

A beautiful and even poetic plane blade forged by the famous Chiyozuru Korehide. The carved inscription reads ”Shin, Un, Mu” meaning “God, Cloud, Dream.”

The best steel doesn’t always shine the brightest.

Joe Abercrombie, The Blade Itself

In this the third post in our series about the Japanese hiraganna handplane we will focus on iron and steel and discuss some unique characteristics and even some philosophical aspects of the hiraganna blade. Why? Because to become proficient at using and maintaining a tool, one must understand it more than just superficially.

In addition, we will briefly examine the story of a single plane blade made for a famous carpenter by a famous blacksmith.

The Shin Un Mu Blade 神雲夢の刃

The plane blade pictured at the top of this article was forged 6 years after the end of World War II by a famous Tokyo blacksmith named Chiyozuru Korehide for a famous Tokyo carpenter named Mr. Nomura Sadao. The engraving on the back by Chiyozura states the blade (and matching chipbreaker) was made by him for Nomura Sadao and completed on June 4, 1951. Chiyozuru charged Mr. Nomura ¥10,000.

You will notice that it looks different from most plane blades in that it lacks the beveled “ears” at the right and left corners of the blade’s cutting edge commonly seen in Japanese plane blades.

The beveled corners absent from this blade are necessary with ordinary blades to prevent the cutting edge from extending into the grooves on each side of the blade opening used to retain the wedge-shaped blade in-place. Without the bevels, shavings become jammed between the groove and blade leaving unsightly and inefficient marks and tracks on the surface of the wood being planed. More on this below.

The blade in question, however, has rabbets cut into the jigane at the left and right edges of the blade so the ura area is thicker than the sides which fit into the retaining grooves, and the cutting edge, therefore, does not intrude into the grooves, making beveled ears unnecessary. This is a very logical solution, although it was not actually invented by either Chiyozuru or Mr. Nomura. Apparently, Mr. Nomura first saw the design at a school. He then made a wooden full-scale model and asked Chiyozuru to forge it for him.

While it is an elegant solution to a real performance issue, it is much more difficult to make this style of blade than the conventional one, and so never became popular.

On the subject of materials, Chiyozuru is well known for preferring to use imported steel, mostly from England, instead of traditional domestic Tamahagane steel. Although the source of the soft jigane is uncertain, there can be no doubt the steel lamination is made of British high-carbon steel.

Gentle Readers are no doubt aware that Japan has always been a land of many man-made and natural disasters, earthquakes and widespread fires being especially common. To protect this important blade from being lost to posterity, as were so many valuable things during the war, upon his retirement Mr. Nomura entrusted the blade to the Takenaka Carpentry Tools Museum located in Kobe, Japan.

Ironically, a large earthquake struck Kobe on January 17, 1995 killing over 6,400 people and tearing the city a new one. Fortunately, while the museum’s exhibits were jumbled up, this blade was not damaged.

Upon the relocation of Mr. Nomura to the big lumberyard in the sky, his heirs formally donated the blade to the museum where it remains to this day.

The blade has four Chinese characters engraved into its face, the meaning of which is a bit of a mystery. From top to bottom they read 神雲夢, pronounced “Shin, Un, Mu” which translates directly into English as “God, Cloud, Dream.” No doubt there is some deep poetic meaning being expressed through these three characters, but the intended meaning is far above the poor understanding of your humble illiterate servant.

Interpretations from Beloved Customers and Gentle Readers are welcome.

Definition of Fettle

While we are on the subject of literacy, I would like to clarify the meaning of a word pertaining to working on tools, and especially planes.

Gentle readers have no doubt heard the word “fettle” used in the phrase “fine fettle,” usually referring to someone being in good health or physical condition. But it has other, older meanings.

In the British dialect, it means to “set in order,” or “get ready,” from Middle English fetlen to shape, prepare; perhaps akin to Old English fetian to fetch.

Your humble servant uses fettle as a verb, mostly when truing a plane or other tool, but also for adjusting it.

Never let it be said that the Gentle Readers of the C&S Tools blog are less than exquisitely erudite and edumacated.

Blade Details

Misunderstandings abound and deep, pungent rivers of BS often burst their banks when the details of the Japanese hiraganna plane’s blade are discussed; Buckets, mops and even garbage pumps are necessary to clean up the mess. I despair: What to do, what to do?

While it appears to be a simple, crude, even haphazard component to the uninformed, the design of a well-made blade is subtle and its execution elegant. I am confident Gentle Readers willing to forego both the temptations of ridiculous rumor and magic mushrooms for a time will quickly understand. So without further ado, let’s turn on the pumps and get our mops moving.

Laminated Construction

The blade is made by forge-weld laminating a piece of hard high-carbon steel to a larger piece of softer low/no carbon steel/iron. These details are discussed in more detail in the two posts linked to below. It is important to understand these details if Beloved Customer intends to become skillful in using and maintaining Japanese planes.

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

The Ura

The blades of quality Japanese chisels and planes have a hollow-ground area on the blade. In the case of plane blades, it is located on the surface your humble servant calls the “face,” which is oriented upwards when installed in the body. An accurate understanding of this structural detail is essential to using and maintaining the Japanese handplane. We discussed this detail in a previous post linked to below. Please review this post if you haven’t done so previously.

Sharpening Part 10 – The Ura 浦

We discussed how to perform periodical maintenance on the ura in an earlier post. Oh joy!

Another plane blade by Chiyozuru Korehide engraved with many of the brands he used during his career. It has a sweet, sculptural ura.

Blade Retention

The blade of the Japanese handplane is held firmly in-place by the wedging action of the blade in the tapered grooves cut into each side of the mouth opening. This arrangement eliminates the dedicated wedges, usually made of wood, used since at least Roman times to retain the blades of Western planes. It also makes irrelevant the widgets and linkages common to modern planes such as the Bailey-pattern, considered by many to be the pinnacle of plane design in the West. Simple is best, don’t you think?

A common misunderstanding about Japanese planes is that pressure between the wooden body and the back of the blade is necessary to both lock the blade into the body and to eliminate chatter resulting from blade vibration. In response, your humble servant can only increase the speed of the garbage pump and say “poppycock!”

Except in the case of a poor quality body, or one damaged through improper setup and maintenance, the friction acting on the right and left sides of the blade generated by wedging action in the grooves must be sufficient to hold the blade in-place without any pressure on the blade’s back.

And unlike the potato chip-thin blades common to many Western planes, the quality Japanese plane blade of the sort we carry with its relatively thick, laminated construction may have a few female characteristics, such as beauty and elegance, but despite fitting into a truly tiny mouth it simply will not chatter (as you know, it’s chisels and squares that love to gossip).

While some degree of uniform contact between the wooden block and the back of the blade is desirable to steady the blade in-use, many fit their blades (or perhaps “neglect to properly fit their blades” would be a more accurate description) to develop high pressure between blade and bed, making it difficult to adjust the blade and distorting the body unnecessarily. In extreme cases, this pressure can even push out the sole, preventing the plane from working entirely, a situation that has shaken many a poor woodworker to the core! Pixie involvement cannot be dismissed.

We will discuss this subject more in future posts.

Lengthwise Taper

A casual observation reveals that the blade is tapered in thickness along its length, being thickest at the head, and thinnest at the cutting edge bevel. The purpose of this taper is simply to wedge the blade into the grooves in the body. Please note that this wedging action does tend to cause the body to deflect to some degree, something which must be taken into account when fettling the sole, a subject we will discuss in a future post in this series.

Transverse Taper

The blade is also tapered in its width, being widest at the head and narrowest at the cutting bevel.

Ideally the side edges of the blade are in intimate contact with the grooves only where they exit at the top surface of the body, but should normally have no contact in the grooves elsewhere, making it possible to adjust the blade’s projection through the mouth to a uniform distance by gently tapping its head right and left a small amount.

Curved Back

Finally, please observe that the back (vs. the ura) of a quality blade is not flat, but is slightly hollow-ground centered around the centerline of the blade’s length. The amount of this hollow should be more-or-less uniform over the blade’s length.

One purpose of this detail is to lighten the blade’s weight, but more importantly it helps keep the blade from twisting out of alignment in-use. If you have ever made a wooden plane body to fit a blade with a flat back, you may have experienced the irritating tendency of the blade to twist out of alignment under heavy planing forces. This is typically not a concern with the Japanese design because of the curved back detail, so long as the body’s bed is well-fitted to the blade.

Since each blade and its wooden block are a little different, and not yet in perfect accord when new, fitting the body to the blade is one of the first things one must do to a new plane. This fettling operation will be the subject of a future post.

A plane blade by Mr. Ogata. Notice the curved back. Notice also the trimmed and beveled “ears” at the right and left corners of the cutting edge.

Plane Philosophy

Traditionally, everywhere planes were used around the world, a craftsman would commission or purchase the metal parts for his plane and cut the wooden body himself.

In recent history in Japan professional plane body makers called “daiuchi shokunin” 台打ち職人, which translates directly to “plane-body beater” (I kid you not) have become common. These craftsmen fit blade to body making a nearly complete retail product. The end-user, however, is still expected to adjust the fit to his preferences.

Many of these ostensibly completed planes are sold in a “sugu tsukai” 直ぐ使い condition, meaning “ready-to-use.” As witness of this, such planes usually have a wood shaving resting in their mouths when sold. However, the fit between blade and body is intentionally too tight. This is where philosophy comes into play.

There are regional preferences in Japan when it comes to tools, including sickles, saws, axes, adzes, chisels and of course plane blades. In far Eastern Japan, especially the Tohoku area and Hokkaido, thicker, heavier plane blades are preferred, whereas in Tokyo and Western Japan, thinner blades are traditional.

But while discussions of these differences make the hearts of historians go pitter patter, they are irrelevant to persons living outside Japan, so we will ignore them for now.

There are two general, practical approaches to blade size and fit. Carpenters tend to like stiff, thick blades that fit very tightly into the body because they tend to retain their settings better in the rough conditions of a construction jobsite. The downside to the thick blade is that it’s heavier, it takes longer to sharpen, and it’s more difficult to make fine adjustments to.

Craftsmen that do finer, more precise work such as joiners, sashimonoshi, furniture makers and cabinet/tansu makers prefer thinner blades that are quicker to sharpen and easier to frequently adjust to make fine, precise cuts.

We have Mr. Nakano forge the blades for our planes more in the Tokyo style: thicker than some but thinner than most.

Not knowing who will purchase the plane, unless directed otherwise most daiuchi shokunin cut tight-fitting bodies more suited to the carpenter, and assume the user will adjust the blade/body fit to their preference. This is a great idea, and probably the only practical solution, but the reality is that too often the pressure on the back of the blade is so high it ends up creating problems for the user unless corrected.

Too many inexperienced users of Japanese planes, especially amateurs located overseas, learn how to use Japanese planes without knowledgeable supervisors or fellow workers near at hand to notice their mistakes, wack them upside the head, and tell them how to correct their errors (welcome to the gentle world of the Japanese craftsman), and consequently never really figure out how to setup, fettle and maintain Japanese handplanes. I think this is one reason why so many Western woodworkers who give Japanese planes a try fail to ever get satisfactory performance out of their planes and eventually become frustrated.

While your humble servant is eager to provide Beloved Customers all practical support and encouragement, the guidance he can provide is limited by distance, the written word, and the undeniable fact that he is a gentleman of great refinement and exquisite sensitivity (She Who Must Be Obeyed has been known to disagree, but what does she know?).

Therefore, upon making a significant mistake, Beloved Customers must instead call themselves rude names and slap their own heads to aid learning retention. May I suggest “Blockhead” as an appropriate self-imprecation in the case of planes? (ツ)

Conclusion

In this post we considered some of the unique design features of the Japanese hiraganna handplane’s uncompromising and bitterly sharp iron and steel blade.

We even examined a historically-important, unusual, and exceptionally beautiful blade made by a famous blacksmith for a famous craftsman with curious engraving of unfathomable meaning. You can’t make this stuff up.

In the next adventure we will turn our attention to the body of the Japanese handplane, the softer, gentler, wooden component with the mouth that directs and controls the work of cutting.

And I promise we will make some sawdust.

YMHOS

Chiyozuru Korehide (1874~1957), the blacksmith of the blade shown above.

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 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 plane blades chatter and gossip unceasingly!

Other Posts in the Japanese Handplane Series:

Sharpening Japanese Tools Part 30 : Uradashi & Uraoshi

And now at last it comes. You will give me the Ring freely! In place of the Dark Lord you will set up a Queen. And I shall not be dark, but beautiful and terrible as the Morning and the Night! Fair as the Sea and the Sun and the Snow upon the Mountain! Dreadful as the Storm and the Lightning! Stronger than the foundations of the earth. All shall love me and despair!

J. R. R. Tolkien

This article is a continuation of, and probably the conclusion to, our “Sharpening Japanese Tools” series. The last post was one year ago and gave an example of how to employ the lessons taught in the previous 28 posts. At that time, your humble servant promised to discuss the subjects of this post at a later date. It’s later.

Why the delay? Simply because I am an excessively compassionate sumbitch who wanted Beloved Customers who hadn’t already figured out plane blade sharpening on their own to become proficient at regular sharpening operations before worrying about something as bizarre as wacking hard steel blades with hard steel hammers. After all, in the words of Miss Benatar, it’s sometimes a heartbreaker.

But now with the blog teetering on the loose and crumbly edge of the rabbit hole that is the Japanese handplane, we have the choice of either gliding gracefully into its depths or clumsily tumbling down ass over tea kettle (oh my!). Alas, we can tarry no longer.

With his article we will begin our graceful swan-like journey by studying a matched set of operations Beloved Customers need to master to become proficient at maintaining Japanese woodworking blades, one called “Uradashi,” and a related operation called “Uraoshi. If you already have these skills, accept my highest praise. The target audience for this post, however, is those that don’t have experience with uradashi and uraoshi as well as those that want to review and improve the skills they already have.

So spread your wings and fly, my brave cygnets!

Definitions

Beloved Customers should already be aware of the the hollow-ground “uratsuki,” typical to Japanese chisel and plane blades. If not, please review the article at this link.

Uradashi is pronounced oo/rah/dah/she and written 浦出し in the Chinese characters as they are used in Japan. These characters translate directly to “push-out the ura.”

Uraoshi is pronounced oo/rah/oh/she and written 浦押しwhich translates directly to “press the ura.”

These two maintenance operations are performed to restore the blade’s cutting edge to useful condition when the thin land at the cutting edge is almost worn out. We will discuss the why and how below.

Long-term Strategy

Before we start pecking on steel, let’s consider our sharpening strategy.

Professional-grade blades are not only expensive, they are difficult to make, hard to find, and require an investment of time and effort from the user if they are to deliver high-performance results over many years. To minimize the required expenditure of time and effort, and to maximize the results delivered, we need more than just technique, we need a maintenance strategy.

In previous posts in this series we have discussed multiple strategies, some physical, some psychological, and even a few supernatural ones. The following is one I strongly urge Beloved Customers to adopt:

  1. Get the ura in good fettle, and then;
  2. Avoid working the ura on anything but one’s finest-grit sharpening stone thereafter, (with the exception of uraoshi following uradashi, of course).

Simple, no?

The ura is formed by hollow-grinding a lamination of extra-hard high-carbon steel (at least in the case of C&S Tool’s chisels, planes and knives). Because it is hard layer of steel is time-consuming to abrade, a wise craftsman will work to keep the ura as deep as possible, and the flat lands surrounding the hollow-ground ura as narrow as possible, as long as possible, thereby minimizing the area of hard steel that must be abraded with each sharpening.

But no matter how careful we are to preserve the ura, sharpening the bevel makes the blade incrementally shorter, so the day will come, at least in the case of plane blades, when the land at the ura immediately behind the cutting edge, called the “itoura,” (pronounced ee/toh/oo/rah, meaning “ thread ura” ) becomes as thin as a thread. Once it disappears, the blade will no longer function. This is the only drawback to the Japanese ura feature, and can only be solved by bending brittle steel.

Bending Hard Steel

The goal of uradashi is to cause the lamination of hard steel at the cutting edge to bend towards the ura so that when we subsequently abrade the bent portion of the ura the itoura land will be restored.

Now if you think about this for a second you will realize that trying to bend a thin plate of steel hardened to Rc65~66 without snapping it is a fool’s errand. In the case of Japanese blades it is possible to accomplish but only because of the thicker, cushioning layer of soft low-carbon/no-carbon iron, called the “jigane,” to which the hard steel layer is laminated.

Your humble servant struggled at first with uradashi, in part because every explanation I read about the process in both English and Japanese was written by people who either didn’t really know what they were talking about, or were too lazy to explain it well. Some years, several broken blades, and much heartbreak later I finally figured it out. Better information is available nowadays, but there is still plenty of BS out there to shovel.

The first key point to understand and always remember is that uradashi is not about using a hammer to bend the hard steel layer; Never ever ever never touch this steel with your hammer! I forbid it on pain of 20 lashes with a wet noodle.

Instead, the goal is to peck on the soft iron jigane layer of the laminated blade at the bevel, as described below, expanding it so the hard steel layer laminated to it will curve in the direction of the ura without snapping or cracking. Please read the previous three sentences again, offer a prayer of remembrance to the gods of handsaws, and click your heels three times (ruby slippers are not mandatory(ツ)).

The second key point you need to grasp around the neck with both hands and dig your Jimmy Choos deep into is that it is indeed a fool’s errand to try to bend the soft iron lamination by the power of your mighty arm, Oh Lord of Thunder. No, we must be as clever as Loki.

So, how do we cleverly do this job, and what tools should we use?

The 60mm blade used in this example forged by Mr. Uchihashi Keisuke from Swedish K-120 steel. The brand name is “Keisaburo.” An excellent blade and still functional, but the itoura is getting a little skinny.

Tools

You will need the following tools to properly perform uradashi and uraoshi on a blade:

  1. A small hammer. Great force is neither necessary nor useful, but you must be able to control this hammer very precisely, so the lighter the better. One with a pointy end like a funate or a Yamakichi or the corner of the thin end of a Warrington hammer is ideal because it focuses maximum pressure on a small area, deforming the jigane efficiently, and it is also easy to see where the hammer will impact providing better control. And control matters a lot because if you miss and strike the hard steel at the cutting edge it will be damaged and bitter tears will flow. Consider yourself duly warned, Oh Might Thor;
  2. An anvil of sorts. This can be any piece of steel with some mass and with a rounded-over corner. A piece of railroad track is great. I use the face of a small sledge-hammer clamped in my vise. A sharp corner is not good, so grind or file one and then smooth it. A piece of thin postcard material glued to this rounded corner help keeps the blade from slipping;
  3. A small square or straightedge;
  4. A marking pen or scribe to mark the “target area” on the bevel;
  5. A rough diamond plate/stone or a mild-steel kanaban plate + carborundum powder;
  6. Parking pen or Dykem for coloring the ura’s lands;
  7. Regular sharpening tools (stones, water, etc.).
A small sledge hammer used as an anvil by clamping it in a vise with another clamp as a stabilizer.

Target Area Layout

Let’s begin by laying out the target area on the soft iron jigane at the blade’s bevel with a marking pen. Or you can scratch lines into the jigane with a metal scribe. This target area will indicate the area you will peck with your little hammer producing many small dents. You must not strike outside this target area even if tempted with donuts.

The striking area marked with marking pen.

The dents you will make with your little hammer need to be limited to a band on the jigane parallel to the cutting edge and beginning 2~3mm from where the jigane lamination begins extending to the end of the jigane lamination at the blade’s back, in the case of plane blades, or the face where the brandname is engraved in the case of chisel blades. Make a line with your scribe or marking pen the full width of the bevel at this distance from and parallel to the cutting edge. Everything above this line in the direction of the blade’s back, in the case of plane blades, or the face where the brandname is engraved in the case of chisels and knives, is the primary target area. Make sure you get this right.

The dents need to extend across the full width of the jigane layer, except where the corners (ears) have been ground to a bevel at the right and left end of the blade, so the right and left limits of the target area are delineated by the ears.

Although we need to tap the full width of the blade to avoid stress concentrations, there is nothing to be gained by trying to bend the far right and left corners of the blade, so we want to focus approximately 2/3rds of our hammer impacts and the resulting dents near the center 1/3 of the blade’s width. Mark the right and left limits of this central area on your blade with a marking pen or scribe.

The Grip

If you are right handed, hold the blade in your left hand with your index finger extended and pressed against the ura parallel with the cutting edge, and about 5~10mm away from it. Press down with your thumb on the blade’s back clamping the blade between your thumb and the side of your index finger. Your other fingers should support the blade from the ura side.

This shows how to hold the blade on the anvil.

Your index finger will be the fence that keeps the blade in proper alignment during the tapping-out process.

Next, we need to figure out how to align and move the blade on the anvil, as well as where to place hammer blows in relation to the blade and anvil.

This photo shows the grip without the blade in the way. Notice how the index finger is touching the anvil. The blade is shifted right and left using the index finger as a fence to keep blade and hammer under tight control.

Manipulating the Blade on the Anvil

Place the blade’s ura on the rounded corner of your anvil. You may want to tape or glue a piece of thin cardboard, postcard, or manila file folder to the anvil’s corner not so much as a cushion but to help prevent the blade from slipping, but this is not mandatory.

Adjust the distance between your extended index finger and the cutting edge as necessary so your finger is touching the anvil stabilizing its position, and so you can slide the blade to the left and right indexing off your finger to keep the target area in proper alignment.

Next, while still in position facing your anvil and with hammer in hand, move the blade aside and tap the rounded corner of your anvil with your hammer lightly. Memorize this location and your position because every tap from now on must be aimed at this same exact spot on the anvil.

The Tap Dance

The time has come to begin the dance.

Reposition the blade on the anvil and use your little hammer to tap the soft jigane layer at the bevel (only the jigane!) in the target area you marked earlier making a row of small dents in it.

These small dents don’t need to be pretty or uniform. Be patient because you may need to make hundreds of pecks, each one quite precisely.

Here is the key point to understand: You want each little dent to cause the jigane to deform and expand in length and width a tiny bit, gradually, until a significant degree of deformation accumulates. The hard steel layer, however, will constrain the jigane layer from expanding, causing the blade to bend, and causing the hard steel layer to deflect and curve towards the ura, bending it without breaking it. It doesn’t seem possible at first, but I promise it will happen, so please be patient.

The trick then is to use the grip described above and use your forefinger to index the blade against the anvil while moving your hand, along with the blade, a tiny bit right or left with each strike, with the each point of impact firmly supported on the anvil, in-line with the hammer blow, thereby squishing the jigane between hammer and anvil. In this way, since the hammer is always aimed at the same exact point on the anvil, you don’t need to worry about realigning it with each blow, removing several difficult-to-control variables from the tap dance at once.

Remember, keep the hammer and anvil precisely aligned, and move the blade left and right, not the hammer. It helps to touch the inside of the elbow of the arm using the hammer against your side in a fixed location to help maintain a consistent hammer swing and distance. Until you have mastered consistency, speed is risky.

Another key point to understand is that, unless the point of your little hammer’s impact is not directly in-line with the point where the ura on the opposite side of the blade is touching the anvil, the force of the hammer’s impact will tend to cause the unstable blade to jump and wiggle around instead of deforming the jigane. This wastes time and energy and makes it difficult to make precise taps.

Here’s a video of Eleanor Powell tapping away with great control, and with the aid of her faithful Fido. I don’t recommend including a benchdog in your tapping-out routine other than as a deterrent to any pernicious pixies lurking in your workshop eager to cause you to miss with your hammer and chip your blade. Evil pixies!

Here’s a video of Sarah Reich tap dancing with every strike landing precisely in the target area. I need to get a pair of shiny red lycra pants like her to go with my most excellent aluminum foil hat with the curly copper wires and red fringe. Do you think they would make my butt look huge?

Remember, force is neither necessary nor useful. The goals is to make many precisely aligned tiny taps producing many small deformations in the target area, with no impacts on the hard steel layer.

Dent Removal

We talked about “dents” above. If you are using a round-faced hammer, those dents will be little crescents. If you use a hammer with a tiny striking face on one end like a Yamakichi or Funate, that tiny face will dig into the metal making ugly little peck marks instead of pretty little crescents. I have used all varieties of hammers but prefer the ones with pointy ends because they impact face is small and, it seems to me, easier to control. Six of one half-dozen of the other.

But remember that we will abrade away all those dents/craters after a few sharpening sessions, so appearance is of zero importance.

The Goldilocks Itoura

The goal, of course, is to bend the blade at the ura land just behind the cutting edge enough to create a useful, flat ura. But how wide should the itoura be when the process is complete? Among plane connoisseurs a narrow itoura is, like a willowy super model, considered a thing of beauty. By narrow I mean some where around 0.50~1.0mm.

A narrow itoura does indeed look sexy, so much so that fashion-conscious plane blade blacksmiths make a skinny ura a point of pride. And, in fact, a bulimic itoura makes it easier and quicker to sharpen the blade because the square millimeters of hard steel one must abrade/polish is minimal compared to a wider itoura.

The downside to the super-model itoura is that it wears out sooner, making it high maintenance. Now, I’m not suggesting that if your plane blade has a super-skinny itoura it will demand weekly spa visits, twice monthly trips on a G700 jet to the Vienna Opera, annual ski holidays in Verbier, and bi-annual boob jobs, but there is no doubt you will need to do the uradashi tap-dance more often. Shiny lycra pants are optional, but ooh sooo sexy.

On the other hand, a wider itoura of 3~4mm has some advantages too. It’s easier to fit the chipbreaker (uragane), and you don’t need to do uradashi/uraoshi as often. Much wider than this, however, and I find it can be difficult to get a screaming-sharp edge at times. Moderation in all things, I guess.

I don’t know how to describe when to stop tapping-out the ura to obtain a good width for your itorura because every blade is a little different, but after doing it a few times you will develop a sense of when enough is enough. However, to develop that sense you should make frequent checks on your tapping-out progress by placing your handy dandy straightedge or square right on the itoura parallel to the cutting edge and sighting between the blade and the straightedge/square with a strong light shining at the gap. You will be able to see the itoura gradually bulge upwards at the center. Even a little bit of a bulge will give you a useful itoura, so don’t get carried away.

Uraoishi

Once the tap dance is done, we need to grind down the ura to form a new itoura.

The traditional method is to use the mild steel kanaban lapping plate mentioned above, although any true lapping plate will work. One sprinkles a small amount of carborundum powder on the plate along with a little water, and works the ura side to side grinding down the bulged area to make a flat.

The problem with lapping plates and carborundum powder is that not only is it a messy process, but unless you are careful to keep the right amount of wet grit on the plate, the results tend to be a tad irregular. I recommend using diamond plates because they produce more consistent results quicker.

Whether you use a kanaban lapping plate or a diamond plate, it is important to focus pressure on the thin area where you need the itoura to develop. Pressure anywhere else is not helpful, but only wears out the itoura prematurely.

Here is wisdom: When they first attempt uraoshi most people try to stabilize the blade by applying uniform pressure across the back of the blade. This seems to makes perfect sense, but it always results in grinding a nasty little trench in the ura where it touches the extreme edge of the kanaban or diamond plate. Remember, the uraoshi process tapped out a bit of metal right at the cutting edge, and mostly at its center. This is what you need to abrade, NOT the right and left lands of the ura, and certainly no more than 3~4mm from the cutting edge. So carefully focus the pressure you apply during uraoshi only on the thin area where you need to restore the uraoshi.

Some people like to apply a thin strip of paste wax, perhaps 3~4mm wide, on the edge of their kanaban or diamond plate to prevent it from digging ugly trenches in their beautiful and delicate side lands. Others like to apply a thin strip of mylar tape at the same place for the same reason. These techniques all work, but professional sharpeners don’t use them because they know how to apply pressure correctly.

A quick touch of the blade on the diamond plate shows where the black marking pen ink has been removed, and the highest spots on the bent itoura.

After the itoura has been restored (perfection is not necessary), polish the blade using your normal sharpening routine.

The restored itoura.

The bevel after working it on the diamond plate and stones. The remaining peck marks will disappear entirely after a few sharpening sessions.

Chisel Blades Versus Plane Blades

Uraoshi and uradashi are operations typically, but not exclusively, performed on plane blades. About the only time chisels need to have uradashi performed is to restore the itoura after the blade receives major damage, like a big chip. A sad event all users of Japanese tools experience from time to time

There is a structural difference between plane blades and chisel blades one must understand when considering performing uradashi on a chisel blade.

Plane blades have a steel lamination that is more-or-less uniform in thickness because that’s all that’s necessary. Chisel blades, on the other hand, are subject to much higher bending stresses than plane blades, so to prevent yielding and failure, traditional chisels are forge-laminated with the steel lamination wrapped up the right and left sides of the blade, forming something akin to a structural steel U-channel, producing a higher moment of inertia, and therefore greater strength and rigidity,

Because of this additional strength, chisel blades are more difficult to bend at the right and left sides using uradashi techniques compared to plane blades. Indeed, they may break if you try.

Since you can only hope to safely bend the steel lamination in areas away from the more rigid sides, uradashi operations on narrow chisel blades will go as smoothly as throwing a cat through a screen door. I wouldn’t even try it on any chisel narrower than 24mm. Beloved Customers have been warned.

If you feel compelled to attempt uradashi on a chisel blade, my only advice is don’t peck within 3mm of the right and left sides.

With this article, our Sharpening Japanese Tools Series is complete (probably). I hope it has been helpful. If you’ve had the patience to read it all, and the clairvoyant ability needed to understand most of it, then you know a heck of a lot more on the subject of sharpening than I did when I started the journey. At least you have received some great ideas for sexy new additions to your simply mahvelous woodworking wardrobe!

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 Iron Pixies pass gas in my cornflakes every morning.

Links to Other Posts in the “Sharpening” Series

Japanese Handplanes – Part 1: East Vs. West

The Road goes ever on and on,
Down from the door where it began.
Now far ahead the Road has gone,
And I must follow, if I can,
Pursuing it with eager feet,
Until it joins some larger way
Where many paths and errands meet.
And whither then? I cannot say.

The Road goes ever on and on
Out from the door where it began.
Now far ahead the Road has gone,
Let others follow it who can!
Let them a journey new begin,
But I at last with weary feet
Will turn towards the lighted inn,
My evening-rest and sleep to meet.

Bilbo Baggins
C&S Tools Sukezane brand 70mm finish plane. Shirogami No.1 steel blade hand-forged by Nakano Takeo, body by Inomoto.

Your humble servant has received many inquiries over the years from Honorable Friends and Beloved Customers (may the hair on their toes never fall out!) about how to setup, maintain and use Japanese planes to which I have gladly responded when the request for information was made politely.

The Japanese hiraganna handplane is an elegant tool with a simple yet deceptively sophisticated design. It is not a difficult tool to master once one understands its unique design principles and learns a few basic techniques easily taught in person, but it can be frustrating to master using only written guidance.

But I believe the time has come to begin this journey. I pray Beloved Customers will have the courage to accompany me down this road that goes ever on and on until we reach the lighted inn. When we arrive, the first round of root beer will be on me!

Let’s begin the journey by examining some relevant terminology. Don’t forget your handkerchief!

Terminology

The Japanese Yariganna in-use. Prior to the advent of the handplane to the islands of Japan, an approximation of this tool was used for finish-planing the surfaces of wood following the adze. It creates a unique and practical surface texture.

In this and subsequent posts in this series your humble servant will not attempt to educate Gentle Readers in all the Japanese language terms for every part of the plane, nor will I use Japanese conventions for describing handplanes, since that would be about as useful as ice skates on Bambi. Instead I will use standard English language terms wherever possible. There is an illustration below that shows the various components and features along with Japanese language labels for those interested.

Indeed, since the plane is a relatively recent tool in the Japanese woodworker’s toolbox, and has a much longer archeological history in the West, it seems silly to use more Japanese words than absolutely necessary to describe something that did not originate in Japan, and can easily be described in English. I will, however, venture to describe some of the more common general terms specific to the Japanese handplane.

I am neither a lawyer nor a government employee and so see no need to make things more confusing than necessary. I humbly apologize in advance if this approach offends any purists who enjoy being confused.

The standard handplane in Japan, and the one used for creating and/or smoothing flat surfaces (versus rabbet, chamfer or molding planes) is called the “hiraganna,” pronounced hee/rah/gahn/nah, and written using the Chinese ideograms 平鉋 , without emphasis on any part of the word.

The first character 平 is pronounced, in this case, “hira” (there are at least 6 standard pronunciations for this character in Japanese) and means “flat.” makes sense, right?

The second character 鉋 , written “kanna” in the Latin alphabet and pronounced “kan/nah,” means “plane” (as in “handplane”). This character is comprised of two standalone characters combined to make a single character, a common practice in the Chinese and Japanese languages. The one on the left side, 金, means gold or metal, while the one on the right, 包 means “to wrap.” Kinda sorta makes sense. Almost hardly.

The character for kanna was not invented in Japan but is said to have been used in China since the Táng period AD618 – 907, although the tool it represented at the time was a scraper of sorts and not a handplane.

Comparison Between Western and Japanese Wooden-bodied Bench Planes

If your humble servant may be permitted a brief digression on a personal subject, I would like to clarify a point of some small relevance to this explanation of the Japanese handplane.

I have at times been called a Japanophile, and although I confess to being fond of the mountainous islands and the wonderful people of Japan, the years I have spent living in Japan, and my ability to read, write and speak the language were not born of some starry-eyed infatuation or even simple admiration of Japan, but by more practical matters of service obligations, educational pursuits and my work in the construction industry. My point is that I prefer Japanese tools and techniques when I think they are superior, and by the same token prefer Western (or at least American) tools and techniques when I believe they are superior. Consequently, I like to flatter myself that I can provide a relatively unbiased viewpoint, one which will come into clearer focus near the end of this article.

Of course, those who prefer Western tools and techniques will say I am biased towards the Japanese way, while those who prefer Japanese tools and techniques above all others will insist I am biased toward Western tools and techniques. There is no way to win such an argument, so Gentle Readers must judge for themselves. Anyway, back to the subject at hand.

A detailed treatise comparing wooden-bodied Japanese handplanes to steel-bodied Western handplanes would be an extravagant waste of Beloved Customer’s precious time, so I will resist the temptation.

But I would be remiss to not point out that Bailey-pattern steel-body handplanes do have a few serious advantages over wooden-bodied planes in general, while wooden-bodied planes in general and Japanese hiraganna planes in particular have several serious advantages over modern Bailey-pattern planes the thoughtful woodworker should understand.

Some of the advantages of modern steel-bodied Baily-pattern planes over all wooden-bodied planes include the following:

  1. The steel plane’s body is unaffected by seasonal humidity changes and therefore warps less and requires less fettling. This is a huge advantage;
  2. The steel plane’s sole is harder and wears slower than a wooden sole, and therefore requires less fettling. Also, since the sole wears slower, the mouth does not easily become wider, and seldom if ever needs to have a new mouth inlet. This is another huge advantage.

Both of these advantages can have a huge impact on the effectiveness and productivity of the tool over the years.

Some of the advantages of Japanese wooden-bodied planes over steel-bodied planes include the following:

  1. The wooden body is lighter and not as easily damaged as a traditional cast-iron steel-bodied plane’s body which will bend and/or fracture if dropped onto a hard surface (the ductile cast iron used in some high-end planes nowadays is a significant improvement in this regard). Fracturing has been the bane of steel-bodied planes since the beginning. This is a huge advantage;
  2. The plane’s Owner can make a replacement wooden body, exactly as he prefers it to be, quickly and inexpensively;
  3. The wooden sole is softer than a steel sole and therefore is not only less likely to scratch the surface being planed, but tends to burnish it instead;
  4. The wooden sole is easier to true, fettle, and even modify;
  5. The wooden body is lighter in weight and therefore both less tiring to use and easier to transport;
  6. Japanese handplanes have lower profiles so they take up less volume, and are easier to store and transport;
  7. Japanese handplanes have few if any screws or levers so adjustment is simpler, more intuitive, and entirely dispenses with the clumsy, often sloppy mechanical linkage common to Bailey-pattern steel-bodied planes;
  8. And finally, the biggest advantage of the Japanese handplane is, (drumroll please), the blade, if hand-forged from high-quality steel and properly heat-treated, will become much sharper, stay sharper longer and will be easier to sharpen than the blades of modern steel-bodied Bailey-pattern handplanes. No contest. Your humble servant believes the blade’s performance is the most important aspect of a handplane, after all, it is a cutting tool, not a paperweight (although I admit to having a pretty little LN No.1 benchplane in white bronze I use as a paperweight. My associates here in Japan can’t figure out what it is. I tell them it is for shaving kiwi fruit (ツ)).

Allow me to expound a little further on the advantages of the Japanese handplane:

Blade Performance:

A beautifully-polished kanna blade with what appears to be excellent grey jigane and a milky-silver hagane cutting edge. It takes your humble servant’s breathe away.

The Japanese planes we carry have forge-laminated handforged blades made for specialized high-carbon tool steel to meet the performance expectations of professional woodworkers in Japan. The crystalline structure of this steel once made into a blade by our blacksmiths is fine-grained and uniform. Blades are exceptionally hard at 65~66Rc, and remain sharp a long time while being easily sharpened.

There was a time in centuries past when Western blades were of near equal quality, but no longer. Sadly, the blades of most Bailey-pattern planes manufactured nowadays are made of high-alloy steels for which quality control can be easily automated, but which were never intended for handplanes. These steels are undeniably tough, won’t become very sharp initially, quickly dull, and are an “evil screaming bitch” to sharpen (pardon the excessively-technical jargon).

Blade Appearance:

While it used to be that Western wooden-bodied planes had interesting maker’s marks stamped in their blades, such is no longer the case. Japanese planes, on the other hand, make a point of having decorative engraving, stampings and surface treatments applied to their blades for a significantly more interesting presentation of the blacksmith’s art than the plain, boring sanded steel of modern Western planes.

A plane by Usui Kengo with a nekkiri yabane (cut arrow feather) ground and stunningly artful calligraphy handcut into the face.

Reliable Blade Retention:

The blade of Japanese handplanes is wedged tightly into two grooves in the side of the body preventing shifting and rotation, and providing reliable settings. Most modern Western handplanes rely on a relatively complicated and less-secure blade retention and adjustment mechanism.

Simplicity:

The standard Japanese hiraganna plane has at most 4 components: The body, blade, chipbreaker (uragane), and chipbreaker rod. Planes with adjustable mouths will have more parts, but those are not standard planes. Western planes often, but not always, have at least 21 and sometimes more components. Screwdrivers and wrenches are not necessary for adjusting or disassembly of Japanese handplanes.

And all the parts in Bailey-pattern handplanes have built-in slop which grows worse with use and often makes adjustment irritating and sometimes even unreliable.

The Japanese hiraganna does not have a separate wedge or a mechanical assembly securing the blade in-place. Instead, the blade itself is wedge-shaped, narrowing in thickness from the head to the cutting edge, and fits tightly into two grooves, one cut into each sidewall of the mouth opening, for a secure fit, an elegant, simple and utterly reliable design.

The various component parts of a Japanese Hiraganna. There are only 4.

Lower Profile and Reduced Weight:

Japanese hiraganna have thinner bodies and a lower profile than Western Bailey-pattern planes and even Western wooden-bodied planes. Accordingly, they weigh less and take up less space in the toolbox.

While there are times when your humble servant appreciates the extra momentum a heavier steel body affords when making deep cuts, those instances are limited to specific applications. The rest of the time the extra mass is like most government agencies: a pointless burden.

In all other applications, the lighter weight of the wooden-bodied Japanese hiraganna plane is a blessing.

Smoother Surface

Where wooden-bodied plans of all types excel is the superior finish they leave on the wood they are used to plane. That is not to say steel-bodied planes cannot create a perfectly smooth surface, but it is the nature of steel to develop dings and burrs in-use that can leave scratches in the wood they are planing. And while a wooden sole will burnish a wooden surface, the best steel can do is rub it.

Western Steel-bodied Handplanes: The Right Tool for the Right Job 適材適所

There is a saying in Japan I am told comes from the boat-building tradition where many types of wood are used for the various components in a quality vessel that goes like this: Tekizai tekisho 適材適所 meaning: “The right wood for the right place.”

Your humble servant is a pragmatic son of a gun, and a firm believer in using the best tool available to achieve the best results. Accordingly, it would be exceedingly foolish to insist that Japanese handplanes are always the best tool for every planing job. Indeed, I have used a combination of both Bailey-pattern steel-bodied handplanes and Japanese-style handplanes for many decades, selecting the best tool for the specific job at-hand. So what steel-bodied planes do I believe excel?

Scrub Plane

I have found the Stanley No.40 furring plane and especially its more modern equivalent the Lie-Nielson 40 1/2 scrub plane to be superior for removing material when dimensioning lumber (making it thinner and flatter).

This is an extremely simple plane with a narrow, thick blade 1.450″ x 3/16″ ground to a large curvature and a big mouth designed to hog lots of wood. The handles make it easier to leverage body weight into the cuts.

In the case of the LN Bedrock model, the blade is A2 steel, a material developed originally for dies, not plane blades, a tool steel that will never become especially sharp, and which dulls quickly, but once it has dulled to a certain point simply keeps on cutting seemingly forever. And while the blade may become dented and dinged, it will not easily chip, perfect for the rough work of dimensioning dirty and stone-infested rough-sawn lumber.

The ductile iron sole will be of course be scratched by dirt and stones hidden in the wood, but who cares? Better a steel scrub plane than the white oak of my Japanese planes. I consider Lie-Nielson 40 1/2 to be an essential plane in my toolchest.

Block Plane

The steel-bodied Western block plane is also an essential tool IMHO. There are of course Japanese planes with similar dimensions, of lighter weight and with better blades, but they all have one weak point, namely the area right in front of the mouth becomes scratched and wears too quickly. Block planes are often used to trim and clean edges which apply a high point load on the mouth. The fix used in Japan is to inlet a brass plate at the mouth. But if metal is the answer, why not make it metal from the beginning?

Also, I use my block planes for finish carpentry and installations which involves working around hidden finish nails, little pieces of steel that damage wooden bodies and hard blades, but which a steel block plane shrugs off.

I own several block planes, being fond of experimenting with tools, but have found the Lie-Nielson No. 60-1/2 rabbet block plane with nicker to be the one most useful for me.

Jointer Plane

Another Bailey-pattern steel-bodied plane I consider to be excellent is the jointer plane. I once had an old Stanley No.7 jointer plane I bought at a flea market, but it fell from the back of my 1966 VW van many moons ago and suffered the fate common to old grey cast-iron planes, breaking both the body and my heart in half. I bought the Lie-Nielson version many years later and have been pleased with it’s perfomance (my expectations were never very high).

It is a monster at 22″ long and weighing 8-1/4 lbs. I hate the heck out of the A2 steel blade. To make things worse, the sole was warped when I bought it new, so I had to spend hours flattening it on sandpaper and glass. Why do I like it? The cast ductile iron sole is tough and never warps. The extra length makes it especially stable for cuts ending or starting off the piece of wood I am planing. When I have a large surface such as a table to flatten, my No.7 may not cut like a dream or be easy to use, but it always makes the job go quicker.

Conclusion

In this post we have briefly touched on the history, terminology, advantages and disadvantages of the Japanese hiraganna plane. We have also compared it to Western planes, and concluded with several examples of Western handplanes your humble servant believes to be superior to their Japanese counterpart.

I hope you will agree that the Japanese handplane is a tool worth mastering if only because of the excellent work it can help you execute. Besides, they’re a lot of fun.

In the next post in this story of supernatural intrigue and inter-dimensional romance we will discuss how to properly adjust a Japanese hiraganna plane without hurting its feelings.

YMHOS

Look at them,’ mother Troll said. ‘Look at my sons! You won’t find more beautiful trolls on this side of the moon’ John Albert Bauer (1882–1918)

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 my jointer plane break in half and bust my toes.

Other Posts in the Japanese Handplane Series:

Clean Wood

Redwoods

Infringe upon the rights of no one. Borrow no tool but what you will return according to promise. Take no wood, nor anything else but what belongs to you – and if you find anything that is not your own, do not hide it away, but report it, that the owner may be found.

Brigham Young

In this post your humble servant will offer some advice that, if followed, will save Gentle Readers time, money, and wear and tear on their valuable woodworking tools. These are not original techniques; I stole them long ago from professional woodworkers in Japan. Wise Gentle Readers will be as bold.

Inspection & Questions

Before we go any further, Gentle Reader, do me a favor. Check the soles of your steel planes. Unless they haven’t been used much, you will probably discover scratches, some of them may even be quite deep. Do you think whatever made these scratches might also have dulled the cutting edges of your planes at the same time?

What could have possibly created these scratches? Have iron pixies been using your planes to shave bricks?

Unless you have a serious pixie infestation, it probably wasn’t anything as large as a brick, but rather tiny particles in or on the wood you have been cutting. Could these vicious, hard particles have grown naturally inside the tree the wood you are using came from? Is there anything that grows naturally inside a tree that is harder than a plane blade’s cutting edge and big enough to cause such deep scratches? Perhaps these abrasive particles were maliciously concealed inside the growing tree by compadres of the shambling horde of 6-armed, green-skinned, Fanta-guzzling aliens that follow me everywhere?

Or could the damage have been caused by nails, screws or staples left in the wood? Perhaps. Pixie toenail clippings? Happens more often than we realize. Tiny fragments of a divorce lawyer’s heart? Maybe, but they are rare and tougher than stellite. No, it’s more likely the culprit is something harder and more insidious than even Murphy’s pointy purple pecker, a substance all around us, one we often ignore.

Nitty Gritty

Logging Redwoods in Humbolt County California, 1905

Politics and journalism aside, we live in a dusty, dirty world, and although the steel in your tool blades is very hard, ordinary dust and dirt contain plenty of particles much harder. I guaran-frikin-tee you that collision with even a small particle of mineral grit embedded in the surface of a piece of wood can and will damage a blade’s cutting edge.

You may believe the damage is minimal and of little concern, but every time your blade becomes dull, you must resharpen it. Every sharpening session costs you time pushing the blade around on stones, time not spent cutting wood. And sharpening turns expensive blades and stones into mud. This is time and money wasted, lost forever.

And the abrasive action of dirt and grit embedded in wood is not hard on just chisel blades, plane blades and the soles of steel planes, but is even harder on sawteeth and wooden planes.

The damage is not limited to just your handtools either. Take a closer look at the steel tables of your stationary equipment such as your jointer or tablesaw. Unless they are new, you will find scratches. Has that pervert Murphy been smokin dope and humpin sumpin on your jointer’s bed when you weren’t looking?

Nay, Gentle Reader, supernatural causes aside, and unless you have been grinding legal beagle body parts in your workshop, these scratches are clear evidence that the wood you’ve been working is neither as clean as it looks, nor as clean as it should be. You’ve gotta do something about that.

Ruba Dub Dub

So what can you do? Strange as it may seem, the simplest and surest way to get rid of dirt and grit is to follow your mother’s instructions about the cleaning the bathtub: Simply wash it with soap, water and a scrub brush, followed by a rinse.

Bet you never thought of washing wood before have you?

The idea is to wet, scrub and quickly rinse the dirt and grit off the wood, not to make the wood soaking wet, so none of that “rinse and repeat” nonsense, and don’t get carried away with the hose. A bit of dishwashing soap or borax mixed in the water bucket will help lift out dirt and grit.

Don’t forget to pat each board down immediately afterwards with clean rags to remove surface water. Then separate each board, stand it on stickers on-end, or rest it on-edge, and allow time and circulating air to dry it out of the sun.

Remember to wet both sides of each board to minimize warping. And don’t soak a lot of water into the ends.

Disclaimer: It is not well suited for thin material or laminated wood products that might easily warp, or if you are in a hurry, or if you lack adequate space to properly air-dry the wood. 

Whether you wash the wood with water or not, be sure to do at least the following two steps on every board before you process it with your valuable tools.

Scrub Scrub Scrub

First, use a steel wire brush to dry-scrub all the board’s faces both with and across the grain. Yes, I know it makes the surface rougher. Tough pixie toenails. Scrubbing with a stiff steel brush is extremely effective at removing dust, dirt, embedded particles of grit, and even small stones from long grain. Give it a try and you will both see and smell the dirt and particles expelled. Pretty nasty stuff sometimes.

Saw Saw Saw

Second, and this is supremely important, before planing a board either by hand or using powertools, saw 2~3mm off both ends. This is why you have that circular saw with the carbide-tipped blade. If you can’t do that, at least use a steel block plane, drawknife, or other tool to chamfer all eight corners of the board’s ends to remove both surface dirt and embedded grit.

This step is critical because grit and even small stones frequently become so deeply embedded in endgrain that even a steel brush can’t dig them out. But sure as God made little green apples, Murphy will place them directly in the path of your plane blade.

If you do these things, your tools will thank you over many years with abundant chips, shiny shavings and cheerful little songs. Promise.

Yosemite Valley California, 1865

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.” We aren’t evil Google, incompetent facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may the bird of paradise fly up my nose.

Kinshiro Planes 金四郎鉋

Does the Japanese plane in the photo above look a little strange? It should. It’s a specialized plane for cutting decorative latticework used in traditional Japanese joinery and casework. There are more photos of this plane below.

We have a limited number of planes in-stock by a famous craftsman that used the brand name “Kinshiro” 金四郎 when he was active. This brand name translates to “golden fourth man.” It was once common in Japan to give male children names that reflected their order of birth.

Kinshiro is a Niigata Prefecture solo craftsman named Kuriyama Noboru 栗山昇. Born in 1932, he is the second generation in this line. The brand name came from his father’s name, “Kinshiro,” the first craftsman in the line, and reportedly a very severe master. Mr. Kuriyama retired in December 2011. 

Mr. Kuriyama specialized in making plane bodies, but made various other tools as well, including marking gauges, cutting gauges, and kudegoshi using blades provided by his distributor. Mr. Kuriyama’s dual-blade marking gauges (二丁鎌毛引き) are famous even outside Japan.

The blades were forged by a Niigata Prefecture blacksmith named Ishibashi Kenji, who has since left us for the big woodpile in the sky. Mr. Ishibashi used Aogami No.1 steel. I assume he used jigane from the same bridge in Yokohama that Niigata blacksmiths are still using today.

Small tool blades are a niche market served by specialist blacksmiths, so you may have not heard of Ishibashi Kenji-san before, but whatever you do, please do not mistake him with Ishibashi Toshichiro, a Niigata blacksmith who made standard plane blades and got in trouble for unknowingly making weapons for the Yakuza. Tsk tsk. Toshichiro’s blades were unimpressive.

Kinshiro’s products are well-known for their precision, functionality, extremely high quality and subtle style. We have been using Kinshiro products for many years with absolute satisfaction. They have always been expensive, but worth every penny. They have not decreased in value since his retirement.

Although new, and of course never used, these planes are old stock and a few of the blocks have some patina.

Most of them are extremely rare and are no longer made anywhere in Japan. When they are gone there will be no more. We wish we could hold onto them forever, but the time has come to release them into the world.

If you like rare collectable Japanese planes and appreciate exceptional craftsmanship, these will interest you. But don’t wait too long.

The Kinshiro planes we have in-stock are listed in the table below. Prices and more photos are the link below. Even if you aren’t interested in purchasing a Kinshiro plane, the photos are worth seeing. Be our guest. If you have questions please use the Questions Form below.

Link to Photos and Pricelist

ミニ組子 青海波 和風雑貨 インテリア 欄間サンプル タニハタ
ミニ組子 分銅輪つなぎ 和風雑貨 インテリア 欄間サンプル 組子欄間 タニハタ
Kinshiro PlanesWidth
Ireko moulding plane 入子面鉋27mm
Ireko moulding plane 入子面鉋36mm
Etemen Adjustable Chamfer Plane 猿面鉋 30mm 30 °/ 60°
Kiwaganna Skewed Rabbet Plane right hand36mm
Kiwaganna Skewed Rabbet Plane left hand36mm
Kiwaganna Small Skewed Rabbet Plane right hand single blade30mm
Kiwaganna Small Skewed Rabbet Plane right hand single blade15mm
Ovolo Moulding Plane 銀杏面鉋6mm
Ovolo Moulding Plane 銀杏面鉋9mm
Ovolo Moulding Plane 銀杏面鉋15mm
Flat Ovolo Moulding Plane 平銀杏面鉋5.4mm
Flat Ovolo Moulding Plane 平銀杏面鉋6mm
Flat Ovolo Moulding Plane 平銀杏面鉋12mm
Ogee Moulding Plane 瓢箪面鉋6mm
Ogee Moulding Plane 瓢箪面鉋7.5mm
Ogee Moulding Plane 瓢箪面鉋9mm
Ogee Moulding Plane 瓢箪面鉋12mm
Ogee Moulding Plane 瓢箪面鉋15mm
Ogee Moulding Plane 瓢箪面鉋18mm
Ogee Moulding Plane 瓢箪面鉋24mm
Roundover Moulding Plane 坊主面鉋4.5mm
Roundover Moulding Plane 坊主面鉋7.5mm
Roundover Moulding Plane 坊主面鉋9mm
Small Roundover Moulding Plane 豆坊主面鉋2mm
Round Moulding Plane 外丸鉋9㎜
Round Moulding Plane 外丸鉋12㎜
Round Moulding Plane 外丸鉋15㎜
Round Moulding Plane 外丸鉋18㎜
Round Moulding Plane 外丸鉋21㎜
Round Moulding Plane 外丸鉋24㎜
Round Moulding Plane 外丸鉋36㎜
Round Moulding Plane 外丸鉋42㎜
Hollow Moulding Plane 内丸鉋7.5㎜
Hollow Moulding Plane 内丸鉋9㎜
Hollow Moulding Plane 内丸鉋30㎜
45° Mitre Plane 留め鉋 (SOLD OUT)18㎜
Narrow Chamfer Plane 糸面鉋3㎜
Hanagata Kumiko Plane Square No.1 Extra-large 花形組子 角1号特大
Hanagata Kumiko Plane Round No.3 Large 花形組子 3号丸
Osaka Dado Plane 大阪作里18㎜

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.”

Japanese Planes – Mitre Plane 留鉋

道具屋の展示会で掘り出し物に出会うの巻。
#wood #woodworking #woods #金四郎 #留鉋#当時の値段#バイブス#宍戸建具店 #南相馬市#鉋
A Tomeganna Plane by Kinshiro (Kuriyama Noboru)

This is a brief post about an unusual Japanese plane made by an unusual craftsman and used in an unusual way, or at least one not seen often in the West.

The plane is called the “Tome ganna” written 留鉋 which means “mitre plane.” In this case, mitre does not necessarily mean just a standard 45 ° mitre as in a picture frame corner, but the planes pictured above are indeed intended to cut a 45 ° mitre for corner joints between two boards.

It is specialized for cutting a critical part of the secret dovetail mitre joint used for casework, and is a standard tool for cabinetmakers and sashimonoshi in Japan.

The plane rides on its beveled sides when shooting the mitre joint.
This page has illustrations of how to cut this joint the Japanese way using this plane. 

This job can be done using jigs and chisels, shoulder planes, or better yet, kiwaganna, but the tomeganna is better balanced and handier, can cut either direction more precisely and quicker, so is a must-have for advanced casework.

If you enjoy casework, the secret dovetail mitre is a challenging joint you really should give a try. The results are great fun, even if they aren’t flashy. 

The excellent Mr. David Charlesworth has even produced a video sold by Lie-Nielson about how to make this joint, although he uses a jig and a paring chisel to good effect.

This is a link to a pricelist and pictures of our limited number of planes by the famous craftsman Kinshiro. You might find the story and photographs interesting.

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.” We aren’t evil Google or incompetent facebook and so won’t sell, share, or conveniently and profitably “misplace” your information.