More Japanese Chisel? -mortise and parring

[Mike Holbrook]

I am about to place an order for more chisels with Stuart. I intend to make quite a few cabinets in the near future and have lots of drawers and door frames to look forward to. I see large numbers of door frames and drawer dovetails in my future. I have been following many threads on SMC and watching videos on tools and methods for this work, Kingshott (Mortise & Tenons, Dovetails), Charlesworth (Technigues for Precision Joinery), Glen Huey (Cheating at Hand-cut Dovetails, which did not turn out to be about what I thought it was). I have also followed the exploits and posts of our own Derek Cohen. I have decided to invest in a couple specialized Japanese mortise chisels and a couple Parring Chisels as well. I have been studying the Tools From Japan products in these areas and would like a little help figuring a few differences in the makers and types of tools available for this work.


Why Japanese Chisels
I was watching Jim Kingshott's video on mortising and was surprise that he used Japanese chisels for the work instead of the more traditional "pig stickers". As I understood his reasoning, he felt it was easier to make an entire mortise with these chisels due to the design of the sides of the chisel blades. The sides of the chisels Jim used were actually hollow ground with rather sharp edges on both sides. I do not know that the hollow ground sides is a big issue and I am sure there are arguments for many different designs. I have read Derek's description of the accurate work he has accomplished with Japanese chisels and a gennou. I have also seen the beautiful work Derek has done using these tools, and his fret saw. I have witnessed the very accurate work Charlesworth does with similar techniques. I also see some possible advantages in the greater variety of sizes Japanese chisels typically are offered in. Certainly there are some advantages to the Japanese steels. I am interested in selecting from the two different mortise chisel types Stu offers on his pages unless there is another alternative I should consider.


Mortise Chisel Manufacturers
The two makers I see that offer mortise chisels are Fujikawa and Koyamaichi. I am speculating that both of these makers turn out quality chisels. I believe Fujikawa built their reputation on mortise chisels and I have read at least one post by a fellow Creeker who likes these chisels. Koyamaichi is a favorite maker of chisels on these pages in regard to their Oire-Nomi, "Dovetail" and I think Parring chisels. I don't think I have found any information regarding their mortise chisels here though. Although the Fujikawa chisels are a little less expensive the difference is not enough to steer me in either direction.


The whole sizing thing
I am struggling to wrap my head around choosing metric size chisels in my imperial world. I have come to understand that particularly in regard to mortises where I will be setting a double gauge by a chisel size, it is ratios not specific sizes that counts. I am also fully aware that chisels for various reasons may not always be expected to be exact sizes. Still I have to buy "specific" sizes. I am a little frustrated when people post that they use imperial chisel sizes that I don't think are manufactured in those sizes (3/16 and 5/16" for instance). I suspect that posters are referring to metric size tools that they are rounding up or down to imperial sizes? If I leap further into the Japanese chisels I have to find some way to reconcile metric and imperial sizing? Unless Stu or someone is having Japanese makers make chisels in off imperial sizes? Even if Stu can have chisels like this made I do not really see a need for them with all the metric sizes available.


In a post on these pages Derek mentions his "favorite" mortise chisel sizes- 1/4, also 1/8 and 5/16. I am betting at least some of Dereks chisels are metric. I am not quite as ambitious as Derek so I plan to skip the 1/8. The issue is the Japanese chisels I am looking at are metric. Kingshott discusses the principal of mortises being 1/3 the size of the piece of wood. Kingshott mentions, in regard to the 1/3 rule, the principal of choosing the slightly larger rather than slightly smaller chisel. Considering that typical door frames are 3/4" and the Japanese mortise chisels come in 6mm (.23622047") and 7.5mm (.29527559") I am trying to figure out which size is better for mortises in typical 3/4" wood? Most US companies list 6mm as 1/4 when it is actually less than 1/4, less than 1/3 of 3/4". For some reason the Japanese chisels seem to skip 7mm and go to 7.5. I am wondering if a 7.5mm falls within Kingshott's realm of a little larger than 1/4", making it a better choice for mortises in 3/4" wood? Might Derek use his 5/16 (.3125") chisel for mortises in 3/4" wood? Maybe Derek's 5/16" (.3125") is actually a 7.5mm (29527559") or just a little more than 1/3 of 7/8"(.29166667")? Since I buy wood finished on both sides and one edge, usually 4/4 or 8/4 I may end up with 7/8" finished boards frequently.


Parring & other Chisels
I want a couple of the classic Japanese push or paring chisels. Stu offers Koyamaichi Usu-nomi chisels. Is there anything else I should look at? Derek mentions a Japanese chisel in his chisel steel test, used to clean up the work from the other chisels, "I used a Funmatsu-Nezumi-Haisu (from Tools from Japan). This is a PM-HSS chisel. A right royal pain in the bottom to sharpen, but it holds an edge like nothing else ..." I don't see this exact chisel on Stu's pages but I do find 'Funmatsu-Nezumi' oire-nomi, made with Hitachi PM-HSS. Are these similar chisels?

[Andrew Pitonyak]

Disclaimer: I am not an expert on anything I talk about here, but, you mentioned this:

I am wondering if a 7.5mm falls within Kingshott's realm of a little larger than 1/4", making it a better choice for mortises in 3/4" wood? Might Derek use his 5/16 (.3125") chisel for mortises in 3/4" wood? Maybe Derek's 5/16" (.3125") is actually a 7.5mm (29527559") or just a little more than 1/3 of 7/8"(.29166667")? Since I buy wood finished on both sides and one edge, usually 4/4 or 8/4 I may end up with 7/8" finished board frequently.

Given the choice, I would probably use the slightly larger chisel over a slightly smaller one. Why? A rough guess based on little, but, my thinking is as follows:

Assume that I cut a 1/4" hole for my tenon. So, I have 1/4" thickness on each side and I shove my tenon into the hole. When I glue that tenon in, I expect that the connection makes a bond that is supposedly stronger than the wood itself. I won't even guess if that is true or not, but, my point is that if I look at a 1/4" side wall, that side wall is glued to the 1/4" inner piece, which is then glued to the other 1/4" side wall. It is also glued to the front and back along the 1/4" thickness.

So, what is the weakest point in the entire joint? I assume (lots of assumptions for an uninformed ignorant person such as me) that the weakest point is that 1/4" piece sticking out of the piece of wood and sticking into the hole right along that intersection point where you may have some end-grain to end-grain glue trying to do its work. If I am looking for shear strength, I assume that the primary holding power is hoping that the 1/4" tenon does not break.

Based on that, I would probably go a little thicker rather than a little thinner. I will freely admit that an extra mm or so will not likely make a difference that matters in practice.

Anyone done any tests on this?

[Jim Matthews]

The size of the chisel determines the size of the mortise, and therefore the tenon.

The big thing is to set your marking gauge to the chisel used, not to the measurement stamped on the side.
If you transfer sizes directly, there won't be any translation errors between units of measure.

Seems to me we bounced $9B off Mars over something like that...

[Kees Heiden]

To make matters worse, what to do with your plow plane? In a typical door, the grooves in the rails and styles are the same width as the mortices. This always perplexes me a bit, especially because vintage chisels and wooden plows are not very exactly manufactured.

[Stuart Tierney]

Mike,

I'll only address the 'size' thing here, just so you and everyone else can understand why the sizes are what they are.

All (and I mean ALL) Japanese tools are sized according to a traditional set of measures based on the shaku, which in woodworking and construction is approximately 303mm. A foot is 304mm, so they're pretty close.

The difference is that the foot is divided into 12 inches, the shaku is divided into 10 sun (pronounced 's-short 'oo'-n) and further divided into 10 bu.

So chisels, as they're narrow, are usually sized in 3.03mm 'bu' intervals. Saws, much longer are in measured in 'sun' (and the tooth pitch are based on the length of the saw, and 'fine' pitch saws use short saw tooth pitch on a longer saw) and planes are measured in length in 'sun' but the blade width is measured where the blade exits the body, but the actual measure used in not known. It's suspected to be 'kujira-jaku' which is a baleen ruler traditionally used by tailors/seamstresses. Nobody knows why that measure was used, but it's the best guess we have.

The 1.5mm, 4.5mm, 7.5mm, etc. sizes are half 'bu' and about as small as can practically be made and used in terms of a chisel.

That's about it really.

Stu.


(Oh, the Funmatsu-Nezumi are only in Oire-nomi, no paring chisels. They are somewhat troublesome to sharpen without decent ceramic type stones, but they will take a very good edge as they're powder metal and keep that edge longer than anything I know of. I'll stop there, no need to slaughter any sacred cows today.)

[Gary Muto]

Mike,

Regarding the paring chisels. I see that Stu offers 2 styles of the flat (non-crank neck) paring chisels from Koyamaichi. Forgive my lack of vocabulary but one is a bevel edge section chisel while the other is the triangular section (dovetail?) chisel. The latter seems better for paring but I'm wondering what others think. I asked the same question on another thread but you seem to have done some research and I'm interested in what you think.

[Mike Holbrook]

Stu thanks for the explanation. I knew there had to be some rhyme or reason to it. The 7.5mm (.29527559)" chisel relates well to imperial sizes by virtue of it being over 1/3 of 3/4"- 1/4 (.25)" , just over 1/3 of 7/8" (.29166667) and the closest metric size to 5/16".

I knew Funmatsu-Nezumi were only listed as Oire-nomi, but of course Derek said his was a Haisu, which is what lost me. I am thinking about trying one of those chisels in Oire-nomi. I have these Sigma Select II stones someone sold me that I think are designed for harder steels. They seem to cut the powdered knife steels well.

Gary, I am hoping to get some of the guys who do understand these terms to raise a little fog for those of us trying to learn. The dovetail designation in Japanese chisels may have a different meaning than it does in regard to western chisels. I did not get into the dovetail vs regular Oire-nomi, beveled sides with flat tops, designs as I had an answer on that question from my more general post on Koyamaichi chisels. As I understand it the dovetail designation refers to the shape of the chisel looking like a birds tail, although many westerners apparently incorrectly assume it means the chisel is designed for making dovetail joints. From the previous post I found that a significant number of posters favored the flat top design vs the dovetail. The issues mentioned regarding the dovetail shape were; the triangle shape can be harder to sharpen and the ridge in the middle can be a hindrance to using fingers on top of the blade. Still quite a few people have the dovetail shaped chisels. I think the flat topped chisels are a little more sturdy and may be easier to use for those of us who may be learning.

I also notice that under the Koyamaichi Paring and detail chisel designation there are Dovetail socket 'bachi-nomi' chisels. In the West we might call these fishtail chisels, due to the V shaped tip. Although these chisels may be good for cleaning dovetail joint corners, I suspect that the Japanese again use the designation because the shape resembles a birds tail. Fish tail, bird tail lets just settle on V shaped!

[Dave Beauchesne]

Mike: I will stay out of the ' types ' of chisels you have listed - the tidbit I would like to add is that my 1/8'' bench chisel is one of my most used - as well, I have an unknown name 1.5 mm Japanese chisel that gets a lot of use. I don't size my dovetails to any specific size ( I lean towards narrower pins BTW ) I just mark them to what looks correct. When I constructed a small Tansu for our son and his Japanese wife, I used three tails on each of the small drawers - four would have looked better in my eye, but three is considered a much luckier ( preferable ) number in Japan. Good luck with your choices.

[Stuart Tierney]

When I constructed a small Tansu for our son and his Japanese wife, I used three tails on each of the small drawers - four would have looked better in my eye, but three is considered a much luckier ( preferable ) number in Japan. Good luck with your choices.

4 is shi or yon in Japanese, and shin is 'dead', so the closeness of 'shi' to 'shin' is pretty obvious.

I'm not up all of these kinds of things though, and my worst faux pas was once wearing toilet slippers out of the toilet.

(The slippers is a typical 'from out of towner' mistake, and the locals watch for it in the new arrivals. Nobody saw me make this grievous error because after 10 years, you're supposed to know better... )

Stu.

[Stanley Covington]

I am hoping to get some of the guys who do understand these terms to raise a little fog for those of us trying to learn. The dovetail designation in Japanese chisels may have a different meaning than it does in regard to western chisels. I did not get into the dovetail vs regular Oire-nomi, beveled sides with flat tops, designs as I had an answer on that question from my more general post on Koyamaichi chisels. As I understand it the dovetail designation refers to the shape of the chisel looking like a birds tail, although many westerners apparently incorrectly assume it means the chisel is designed for making dovetail joints. From the previous post I found that a significant number of posters favored the flat top design vs the dovetail. The issues mentioned regarding the dovetail shape were; the triangle shape can be harder to sharpen and the ridge in the middle can be a hindrance to using fingers on top of the blade. Still quite a few people have the dovetail shaped chisels. I think the flat topped chisels are a little more sturdy and may be easier to use for those of us who may be learning.

I also notice that under the Koyamaichi Paring and detail chisel designation there are Dovetail socket 'bachi-nomi' chisels. In the West we might call these fishtail chisels, due to the V shaped tip. Although these chisels may be good for cleaning dovetail joint corners, I suspect that the Japanese again use the designation because the shape resembles a birds tail. Fish tail, bird tail lets just settle on V shaped!

Quality Japanese chisels are worth the price due to a better design and better cutting performance. But it depends on the ability of the user to setup and sharpen them properly.

The triangular cross-section chisels sold in the US as "dovetail chisels" are called ”Umeki Nomi” (埋木鑿）meaning "Inlaid Wood Chisel, or "Shinogi Nomi"　(鎬鑿) meaning "ridged chisels" in Japan. The "ridge" term refers to the shape of the back, and this same word is used for the shape of the back of one style of Japanese sword. They are very useful chisels and can get into many tight places a standard paring chisel (usunomi (薄鑿）= thin chisel) can't. They do have one shortcoming. They can't get into really skinny mortises like a standard usunomi can because the ridge gets in the way. They are stiffer than usunomi, and easier to sharpen IMO because the deeper back helps index the angle more consistently. I had a set custom made 20 some odd years ago in Tokyo by Mr. Shimamura (Kiyotada 清忠)。They are beautiful and very sharp. I prefer the shinogi chisel to the standard paring chisel, because I find them more useful.

Shinogi are difficult to make, I am told, because the differential shrinkage during heat treatment of the unusual cross section makes then tend to crack at the front corners, especially when using White Paper Steel.

I think they are sold in the US as dovetail chisels because Americans are obsessed with dovetails.

I have never seen a bachi nomi in person, and the tool retailers I have questioned in the Tokyo area haven't either, nor are they shown in their wholesaler's catalogs.

The idea that chisel widths should be matched to imperial or SI units in handwork has limited merit. They only situation where it makes a difference is when a chisel must match a groove or slot or mortise or other cut made with a router or dado blade or other machine, or some piece of mass-produced hardware. The important thing is to have a good selection of widths so you can design your width of cut to work well with the width of the workpiece. This is a matter of structural strength and durability and interference (construction terminology), and so having a good selection of chisels is very important. The idea advocated by some scribblers that one needs only 3 or 4 chisels to do all woodworking is absolute nonsense, and is akin to a fellow telling everyone in every situation that, because his Ford pickup does everything he needs a vehicle to do, sedans, vans, and large trucks are unnecessary. I say buy the chisels that provide you the best performance, in the types and sizes you need to do the job right in every situtation, and use them a lot.

The shaku is interesting. It originated in China and was once a measurement of the length of some despot's ulna bone. And like all such measurements around the world, it changed with different despots and changing dynasties. The Chinese character is 尺, and is a pictogram of a hand with thumb and index finger extended, symbolizing a measurement being made between the tips. In my case, this is 8".

The shaku was (and still is) used in many Far East Nations, including Japan, where it changed with time and application, different trades and different locales adopting different lengths, with the shaku used by carpenters being perhaps the most stable across the many islands and fiefs and kingdoms that comprised fractured feudal Japan. Over time it tended to get longer because, some historians say, a longer shaku tended to reduce the gross taxes paid on goods assessed by length. In 1868 the Meiji Government unified the shaku at 10/33 meters (in China it is now 1/3 meters).

Stu is right about the number 4 being considered unlucky in Japan because one pronunciation is "shi" which is the same for "death" (死). 9 is also bad because one pronunciation is "ku" which is the same as "suffering" （苦）. Also, four and other even numbers are not seen much in nature, so uneven numbers are thought to be more in harmony with nature and spiritual matters (often seen as the same in Japan).

The old gentleman that taught me to make tategu once told me to avoid making shoji or other latticework with an even number of kumiko lattice pieces, because, first, such tategu is not in harmony with nature and is therefore unlucky, and second, because even-numbered latticework was reserved for tategu in entertainment houses (brothels and gambling dens) and therefore not acceptable for normal applications even if the client didn't know better. I have heard the same thing from other sources, so I must assume it was once an important distinction in the building industry in Japan generations ago. When I have any say in the matter, I ask designers on my projects to not use even numbered latticework even in stainless steel doors or balustrades. No joke.

2 drachma.

[Gary Muto]

Mike,
Thanks for the response. It gives me something to think about.

Stanley,
Thank you for posting too. You provide a lot of good insight and some entertainment.

[Mike Holbrook]

Stanley,

Thanks for the enlightening post, which clears up several areas of fog in my thinking. My largest current issue is figuring out what "slightly" larger means in metric terms. Is a 7.5mm chisel slightly larger than a 1/4" for instance? Since 7.5MM is the next size larger than 1/4", the only option I see is altering the thickness of the stock...

I get that it is hard or pointless to try and match imperial and metric tools. One of the frustrations I have had is posters seem to describe Japanese chisels in imperial sizes. I assume people do this so we imperial minded people have a better idea of what size they are discussing. I am not so much trying to match metric and imperial tools as select metric tools of a size that will cut mortises, dovetails... in appropriate sizes in the wood I have. I just bought a Steel City planer that is imperial. The wood I buy comes cut to imperial sizes. I imagine there are ways I could process this wood via the metric system but at this juncture I am having trouble wrapping my brain around thinking in metric. Unless I make changes in my measuring, processing and thinking apparatus I still have to work with wood that is an imperial size, 3/4", 1/2", 1/4" being typical for the door frames and drawer parts I will be working with. The plans I have are imperial too. I think Stanley is suggesting that the way to handle this situation is to have a greater variety of sizes to choose from, which may be a workable if costly methodology.

Maybe I worry less about matching sizes and fill in metric sizes I don't have? Even if I had all the sizes I would still have to select the appropriate one.

[Jack Curtis]

Mike, I told my first Japanese tool seller, Harrelson Stanley, that I wanted to build shoji to start with, and he said to buy 4.5 and 7.5 mortise chisels, that they are much used for shoji. This was true. Having built a few now, I can say they're very similar to building/designing cabinet door frames and cabinet fronts. And I still have and use both chisels, both by Tasai.

[Jim Koepke]

My woodworking has improved since giving up trying to meet exacting measurements.

Less wear to the ruling tools, more work for the sizing tools. (In other words, don't let a tape measure rule your work.)

Dovetail layouts are sized to my chisels. With my most recent project a 1/4" chisel is going to be doing the most paring work. There must be about a half dozen 1/4" chisels in my shop in different renditions of 1/4". Layout is done with the fattest one so all the others can be used if needed.

Switching to story sticks has many advantages; less mistakes, better accuracy and faster than using measuring tapes and rules.

In situations where one must match a plow blade and a chisel, it isn't impossible to correct one to match the other. A 5/16" plow blade shouldn't be too difficult to work down to match a 7.5mm chisel. It is only about 0.4mm to remove.

jtk

[Mike Holbrook]

I went to a cabinet making demo at Highland Woodworking which was very interesting. The guy doing the work used all hand tools and no measuring devices. He did everything by tool sizes and the size of the stock he had. I understand that way of working. I think my issue is I come from 10 years of construction projects where many things are built to fit stock materials with as little change to the materials as possible. I understand things are different when you make the materials things are built from, but it isn't always easy to think differently.

Jack thanks for that insight into mortise chisel sizes, I will get both of those sizes. Do you have anything to offer regarding the Koyamaichi mortise chisels vs the Fujikawa? You probably have a third type right?

Interestingly the orei-nomi and paring chisels come in different sizes. The 'Funmatsu-Nezumi' oire-nomi I was looking at come in still a different set of sizes.

Jim I hear you I have the same destination just trying to locate steps on the path. I am about to buy a double marking gauge with no scale, it's a start. The idea of modifying a plow plane blade had occurred to me and I think I have the sharpening/lapping tools to do it painlessly. I think when I get enough experience to picture metric sizes it will help.