Ichimatsu Chisel

[Stanley Covington]

I would like to show you a rarely seen specialized paring chisel called the Ichimatsu Nomi (Nomi means chisel in Japanese). I hope you find it interesting.

This tool is used almost exclusively by joiners (tategushi 建具師) to precisely pare the many angled joints necessary to create smooth transitions between chamfers and other edge profiles at intersecting wooden members, such as rails and stiles, when making wooden doors, screens, dividers, windows, frame and panel interior woodwork, and coffered ceilings.

The most common cut is paring the 45 degree angle mitre where the chamfer or edge profile of a rail meets a stile. The chisel rides on a 45 degree wooden jig to pare the mitre very precisely.

To have a gap or mismatched angle at this sort of mitre is considered very embarrassing in Japan, and must be avoided. An open or poorly fitting mitre is said to be “ laughing,” in derision of the craftsman that made the joint, and is said to mock its maker for as long as it exists.

The chisel in the attached photos is mine. I had it custom made over 25 years ago in imitation of my Master’s by a renowned Tokyo blacksmith named Mr. Kosaburo Shimamura (島村幸三郎). During his lifetime, Mr. Shimamura was praised by metallurgists as the very best chisel blacksmith in Japan.

I have used this chisel a lot, so the blade is probably 2cm shorter than when it was new, and the ura, while still useful, have become considerably shallower.

While it is obviously a paring chisel, it has some unusual design features. Specifications are as follows.

Overall Length: 310mm
Blade width: 24mm
Blade Cross section: Rectangular kakuuchi style.
Ura: 3 - hollow grinds (Mitsuura)
Neck: Flat “Hiramachi” style
Steel: Hitachi Yasuki White Label No. 1 (plain high-carbon steel (1.4~1.2% carbon)
Forging: Hand forged
Finish: Scraper and file
Handle: Japanese Red Oak ( closed grain)

The kakuuchi style is old-fashioned and heavier than the more common mentori ( beveled) style. In this case, it is used for extra rigidity, and to provide a wide, flat top surface for the user to press down on as the blade rides the jig. This chisel is not typically used in tight locations, so beveled sides are not necessary.

Instead of the more common and graceful round neck, it has a flat “Hiramachi” style neck in the same plane as the blade to help it better ride angled jigs without the neck getting in the way or limiting travel.

I am not a fan of multiple ura, and find the detail silly, like putting skinny whitewall pimpmobile tires on a work truck. However, in the case of this chisel, the 3-grind mitsuura is a critical detail.

This chisel is used by holding the handle in the right hand which pushes it into the cut, while the fingers of the left hand press it tight against the jig’s face and guide the blade. If the blade had only a single ura, the pressure acting on the small bearing surface area would quickly wear out the jig.

The increased number of lands makes it possible to work the blade at an angle to, or even partially off, the jig’s face.

I hope you find unusual tools like this one interesting.

I am currently working with my blacksmith to have a reproduction made for a customer.

Stan
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[Frederick Skelly]

Thanks Stan! I enjoyed reading this!
Fred

[Stanley Covington]

Thanks Stan! I enjoyed reading this!
Fred

You are always welcome, Fred.

[Rowan Page]

Interesting, thanks for sharing Stan.

[Stanley Covington]

Interesting, thanks for sharing Stan.

Thanks, Rowan.

[ernest dubois]

Very beautiful symmetry and lines in photo #3. Are we to understand there is no grinding involved in making the chisel?

[Stanley Covington]

Very beautiful symmetry and lines in photo #3. Are we to understand there is no grinding involved in making the chisel?

Thanks. Glad you like it.

I am sure Shimamura san used a grinder to shape it after forging, although I was not there to watch.

It's nearly impossible to obtain beautiful curves, symmetrical lines, and smooth transitions in chisels without using scrapers and files. He was very skilled at this handwork, and had a great eye. And of course, his forging and heat treating skills are unsurpassed. His blades cut and hold an edge better than any I have experienced.

A lot of his tool designs were informed by those of Chiyozuru Korehide.

Plane blades get all the attention, and are relatively costly, but chisels are much more difficult to make, and are subject to more difficult conditions.

[Brian Holcombe]

Thanks for sharing Stan! This is one beautiful chisel :D

[Stanley Covington]

Thanks for sharing Stan! This is one beautiful chisel :D

A man with an discerning eye!

It is an unusual shape to be sure, but it definitely has the simplified "less is more" vibe humming. It is a pleasure to use. I just hope my blacksmith can do a decent reproduction for my customer.

[ernest dubois]

but it definitely has the simplified "less is more" vibe humming.
Yes, its the attraction for sure.

[ken hatch]

Stan,

I'll join the others in thanking you for the post. Japanese chisels are such a beautiful and usable art form and one that unlike most art is accessible to most folks. It is a shame I'm so close to retirement I can't really let my inter tool freak flag fly.

ken

[Jim Koepke]

Thanks Stan,

A little eduction with my morning coffee is always enjoyed.

jtk

[Andrew Hughes]

That's a nice looking tool.
I call that joint the Mason's miter. I cut my Mason's miters the same way.
I also take great care to prepare my space and tool for that one task.
Thanks for sharing

[Georg Zudoff]

Stanley, you wrote that chisel ride the 45 angle wooden jig. Is that jig a simple wooden triangle?

[Christopher Charles]

Stan,

Thanks as always for an interesting post. I'm curious about how this style differs in practice from a paring chisel beyond the three ura? Would a paring chisel with (or without) multiple ura largely provide similar experience?

Best,
Chris

[Stanley Covington]

Stan,
I can't really let my inter tool freak flag fly.

ken

Sounds kinky! :eek:

[Stanley Covington]

Stanley, you wrote that chisel ride the 45 angle wooden jig. Is that jig a simple wooden triangle?

George:

It is quite simple. The jig has one side open, which was facing the camera in the photo, and a long side which extends down and rests against the side of the piece being pared. In the photo, the piece being pared and that side are clamped together in my leg vise keeping them from shifting.


G

[Stanley Covington]

Stan,

Thanks as always for an interesting post. I'm curious about how this style differs in practice from a paring chisel beyond the three ura? Would a paring chisel with (or without) multiple ura largely provide similar experience?

Best,
Chris

You are welcome.

The biggest differences from a standard usunomi are its shorter length, the thick, square kakuuchi shape of the blade which provides greater rigidity, and the flat hiramachi neck which also rides the jig. A typical usunomi's neck will get in the way.

A single-ura blade would not function as well because, unless you kept it aligned on the jig, if the ura shifted off the jig the blade could tilt. The multiple ura also provide an increased bearing area. A standard usunomi will quickly wear grooves in the jig where the lands to each side of the ura touch the jig.

As I wrote above, I don't like multiple ura, but this is the one instance where they make perfect sense.

[William Fretwell]

So your chisel is half an inch from being worn out? Perhaps you need to order two?
What do the ura add? Stiffness?

[brian zawatsky]

That certainly is a beefy paring chisel. I imagine that its heft, thickness, and stability really allow you to make precise cuts cross-grain cleanly. I can see how it is intended to be registered against a jig as opposed to being used freehand. Thanks for sharing, I'm always eager to learn more about Japanese woodworking tools and techniques.

[Brian Holcombe]

So your chisel is half an inch from being worn out? Perhaps you need to order two?
What do the ura add? Stiffness?

It’s not often recommended for chisels but careful ura-dashi can be used when the edge gets very close the end of the ura(s).

In the case of a specialized chisel such as this 1/2” will last some a lifetime of careful use.

[Derek Cohen]

George:

It is quite simple. The jig has one side open, which was facing the camera in the photo, and a long side which extends down and rests against the side of the piece being pared. In the photo, the piece being pared and that side are clamped together in my leg vise keeping them from shifting.

Stan, that is one beautiful chisel. Are the maker still alive? From the way you described their availability, it did not seem so.

George, I have a picture of the jig used here. This is one of mine, used for paring mitres in frames (for frame-and-panel construction) ...

https://s19.postimg.org/xma34oar7/Framemitre1.jpg

http://www.inthewoodshop.com/Furniture/Buildtheframe_html_2a3f4655.jpg

Regards from Perth

Derek

[Stanley Covington]

Stan, that is one beautiful chisel. Are the maker still alive? From the way you described their availability, it did not seem so.

George, I have a picture of the jig used here. This is one of mine, used for paring mitres in frames (for frame-and-panel construction) ...

https://s19.postimg.org/xma34oar7/Framemitre1.jpg

http://www.inthewoodshop.com/Furniture/Buildtheframe_html_2a3f4655.jpg

Regards from Perth

Derek

Thanks for the picture, Derek. My jig is very similar.

The blacksmith has since passed away. 15 years ago?

His son carried on the the work for some years, and I was told he was very good. But he had back problems and gave up the forge for a less physically demanding career with UPS.

It was never the sort of chisel that you would see in a tool store or sales catalog. I have only seen a handful of them, and all those have been owned by professional joiners.

My blacksmith tells me he is familiar with the style, and can make them, but I am still waiting for the first sample. Late May? I doubt there is much demand, but I have had several enquiries for short usunomi with hamachi necks, so it would seem that some craftsmen still need this style of chisel. I know I could never part with mine.

[Stanley Covington]

That certainly is a beefy paring chisel. I imagine that its heft, thickness, and stability really allow you to make precise cuts cross-grain cleanly. I can see how it is intended to be registered against a jig as opposed to being used freehand. Thanks for sharing, I'm always eager to learn more about Japanese woodworking tools and techniques.

Brian

You have grasped the important points exactly.

Stan

[Stanley Covington]

So your chisel is half an inch from being worn out? Perhaps you need to order two?
What do the ura add? Stiffness?

William:

No, it is not worn out by a long shot. But the ura has become a lot shallower than ideal at this point. The multiple ura are shallower than for a standard single-ura paring chisels, even when new, and to make things worse, I have spent too much time working the ura, so they have become even shallower. I use it a lot.

I wish I had two of them, but it was not an inexpensive tool. Shimamura san's chisels were always 2X the price of lesser blacksmith's products, and they were worth it. But this was 4 or 5 times the price of an ordinary 24mm paring chisel.

Japanese craftsmen have always demanded a lot from blacksmiths, not just in terms of performance, but unique designs. In turn, Japanese blacksmiths have always been responsive to the requirements of craftsmen, and found joy in improving their products in conjunction with the end-users. I think this has been a significant factor in Japanese chisels and planes having such excellent designs.

Although they are getting old and numbers are diminishing rapidly, there are still such blacksmiths to be found in Japan, for a few more years anyway. In 15 years, it will become nearly impossible to find someone to forge this sort of chisel, with all manufacturing shifting to mass-production in the Miki style. Only over-hyped mediocre products will become available, I fear.

The blacksmith I have asked to make them for me is 70 years old, for example.

[Georg Zudoff]

Thank you, Stanley.

[Pat Barry]

Thanks. Glad you like it.

I am sure Shimamura san used a grinder to shape it after forging, although I was not there to watch.

It's nearly impossible to obtain beautiful curves, symmetrical lines, and smooth transitions in chisels without using scrapers and files. He was very skilled at this handwork, and had a great eye. And of course, his forging and heat treating skills are unsurpassed. His blades cut and hold an edge better than any I have experienced.

A lot of his tool designs were informed by those of Chiyozuru Korehide.

Plane blades get all the attention, and are relatively costly, but chisels are much more difficult to make, and are subject to more difficult conditions.

Question: why isn't the chisel blade finished to a higher degree / polish? Why the black finish? The tool is obviously hand made given the nonuniformity of the three grooves. Given the apparent fascination with perfection of miters, I'm surprised that same expectation isn't applied to the finish and grooving. I do like the overall proportions though, particularly the sizing/ shaping of the handle. Why wouldn't the steel be polished?

[Stanley Covington]

Question: why isn't the chisel blade finished to a higher degree / polish? Why the black finish? The tool is obviously hand made given the nonuniformity of the three grooves. Given the apparent fascination with perfection of miters, I'm surprised that same expectation isn't applied to the finish and grooving. I do like the overall proportions though, particularly the sizing/ shaping of the handle. Why wouldn't the steel be polished?

Pat

I understand the apparent contradiction.

There have been a few blacksmiths I am aware of that polished some of their blades. Chiyozuru Korehide was one. Such tools were intended to be literal works of art, not working blades. Of course, this requires considerable extra work to do right.

The black finish is the oxidized "skin" created during heat treating. It is somewhat rust resistant, certainly much more than a white finish. The appearance of this skin tells you something about the completeness and quality of the heat treatment, so in a working blade, it is seen as a sign of quality. All such traces are lost when polishing, and so the quality of white working blades are seen as suspect. Such is the nature of hand-forged blades.

In Japan there is a traditional appreciation for factors called "wabi™ and "sabi." This is best seen in the design and construction of teahouses, if you want to check it out.

Of course, the men and tools used to make such structures have been influenced. There is more beauty in the eyes of many in the black oxide skin than a polished steel blade.

Stan

[Stanley Covington]

Thank you, Stanley.

You are welcome, George. Do you see many Japanese woodworking tools in Dnipropetrovsk?

[Pat Barry]

Pat

I understand the apparent contradiction.

There have been a few blacksmiths I am aware of that polished some of their blades. Chiyozuru Korehide was one. Such tools were intended to be literal works of art, not working blades. Of course, this requires considerable extra work to do right.

The black finish is the oxidized "skin" created during heat treating. It is somewhat rust resistant, certainly much more than a white finish. The appearance of this skin tells you something about the completeness and quality of the heat treatment, so in a working blade, it is seen as a sign of quality. All such traces are lost when polishing, and so the quality of white working blades are seen as suspect. Such is the nature of hand-forged blades.

In Japan there is a traditional appreciation for factors called "wabi™ and "sabi." This is best seen in the design and construction of teahouses, if you want to check it out.

Of course, the men and tools used to make such structures have been influenced. There is more beauty in the eyes of many in the black oxide skin than a polished steel blade.

Stan

Thanks for the explanation Stanley!

[Brian Holcombe]

Question: why isn't the chisel blade finished to a higher degree / polish? Why the black finish? The tool is obviously hand made given the nonuniformity of the three grooves. Given the apparent fascination with perfection of miters, I'm surprised that same expectation isn't applied to the finish and grooving. I do like the overall proportions though, particularly the sizing/ shaping of the handle. Why wouldn't the steel be polished?

The black finish is a high indication of quality.

Perfection in Windsor chair making, for example, is often handmade and obviously handmade for reasons that it can be made to a higher degree of quality. A Windsor chair can be made machine perfect and yet it looses a tactile quality and cannot be made as strong.

[Matt Lau]

It's always interesting to see your finds.

[Keith Mathewson]

I’ve always used a jig similar to derek’s (Nice watch by the way). Had no idea there was a chisel purpose made for the job. Given that you are having one made for a customer is it possible to place an order?

[Stanley Covington]

I’ve always used a jig similar to derek’s (Nice watch by the way). Had no idea there was a chisel purpose made for the job. Given that you are having one made for a customer is it possible to place an order?

Keith:

Please send me a PM and I will provide my personal email address so we can discuss outside SMC.

Stan

[Bill McDermott]

Stan,

Very interesting. Thank you for sharing.

Since you have eaten up 2 cm of blade, through a lot of use over 20 years:
1) Do you notice any difference in use?
2) Take a wild guess... Not counting stropping or light touch up hones, how many times have you sharpened (wire edge)?

For those who wonder about the closed grain Red Oak, as did I; the web delivered this explanation on a website for wooden training swords. That's apparently what a "bokken" is.

The Japanese red oak wood used for Japanese Bokken, greatly differs from the Red Oak Wood referred to when speaking about North American Oak. While the North American Oak and Japanese Oak are related, the Japanese Oak tree is evergreen, due to this it does not have a conspicuous open grain like the American White and Red Oak. The open grain structure, of the American Oak wood produces soft areas which are more prone to impact damage. Japanese red oak on the other hand has a structure that is uniformly hard, has excellent dent resistance and has better impact strength than American Oaks.

[Stanley Covington]

Stan,

Very interesting. Thank you for sharing.

Since you have eaten up 2 cm of blade, through a lot of use over 20 years:
1) Do you notice any difference in use?
2) Take a wild guess... Not counting stropping or light touch up hones, how many times have you sharpened (wire edge)?

For those who wonder about the closed grain Red Oak, as did I; the web delivered this explanation on a website for wooden training swords. That's apparently what a "bokken" is.

The Japanese red oak wood used for Japanese Bokken, greatly differs from the Red Oak Wood referred to when speaking about North American Oak. While the North American Oak and Japanese Oak are related, the Japanese Oak tree is evergreen, due to this it does not have a conspicuous open grain like the American White and Red Oak. The open grain structure, of the American Oak wood produces soft areas which are more prone to impact damage. Japanese red oak on the other hand has a structure that is uniformly hard, has excellent dent resistance and has better impact strength than American Oaks.


Bill:

1. I have not noticed an difference. Hardness has been very uniform
2. I have no idea how many times I have sharpened it. A lot.

North American Red Oak is a terrible wood, IMO. American White Oak is pretty good, IMO. Neither is as dense or strong as their Japanese counterpart. I wish it were otherwise.

[Nicholas Lawrence]

Stan, I really like the chisel. I wish we had people making that sort of thing over here.

[Stanley Covington]

Stan, I really like the chisel. I wish we had people making that sort of thing over here.

Nicholas:

I have been on the telephone with my blacksmiths for several days now, and it appears as if I will have a difficult time getting it reproduced even in Japan. Sigh...

[Vincent Tai]

I really hope a reproduction is made somehow, would be a shame to see such a good tool go unreplicated. Once I get a big anvil etc I’ll be spending a lot of time trying my hand at forge welding. Maybe I’ll try and bash out one of these one day. It gets disheartening at times when I snap out of day dreams of making tools and realize whatever I’ll make will be universes away from what Shimamura san made. Please do let us know how the reproduction will go. I’ve been going through your posts and found them most intriguing and enlightful. This one did not disappoint.

Thanks,

Vincent

[Stanley Covington]

I really hope a reproduction is made somehow, would be a shame to see such a good tool go unreplicated. Once I get a big anvil etc I’ll be spending a lot of time trying my hand at forge welding. Maybe I’ll try and bash out one of these one day. It gets disheartening at times when I snap out of day dreams of making tools and realize whatever I’ll make will be universes away from what Shimamura san made. Please do let us know how the reproduction will go. I’ve been going through your posts and found them most intriguing and enlightful. This one did not disappoint.


Thanks Vincent. Nice to be appreciated. Best wishes as you polish your blacksmithing skills. The Blacksmith is the master of all crafts, since he makes everyone's tools. We need more of them.