“All times are good for those who know how to work and have the tools to do so.”
The shinogi usunomi is another variety of paring chisel in the tsukinomi family.
We examined the word ” shinogi” in a previous post.
It means ”ridge” as in the ridge of a mountain, or a building’s roof, or the back of some Japanese swords. Shinogi-style chisels have two wide bevels on their face that meet at the bkade’s centerline creating a ridge. Sometimes there is a narrow flat at the top of the ridge, depending on the blacksmith’s style and customer request.
If the atsunomi is the draught horse, the oiirenomis are the quarter horse, and the usunomi is the falcon of the chisel world ( the one in my slightly addled head, that is), then the shinogi usunomi is a Goshawk, severe in appearance, fierce, strong, fast, and skilled at maneuvering nimbly in tight situations.
Shinogi usunomi have these same two bevels and center ridge as the shinogi oiirenomi. The side edges tend to be thinner than standard usunomi, and with less material in the way, they are often just the ticket for paring into right corners. And because the ridge is higher than the standard usunomi is thick, they tend to be a bit more rigid.
And of course, since it is an usunomi (meaning “thin chisel”) it has a relatively longer and more slender neck and handle, and no crown.
A pox on anyone that would strike one of these beauties with a mallet or hammer.
One downside to this design is that the ridge down the face, which increases the overall thickness of this chisel, may make it difficult to pare down into skinny mortises. Another potential downside, but not one that bothers me, is that the ridge is not as comfortable to press on with your fingers when paring. I find this ridge gives my fingers a better sense of the blade’s precise location in my hand and in the cut. This is all personal preference that can only be evaluated through experience using both varieties of usunomi.
You may be able to tell from my choice of words that I am fond of shinogi usunomi. Indeed, I admit to prefering them. I like how they look. I like how they feel. I like sharpening them. I like how they cut. I like how the extra clearance on the side lets me see what I am paring. Subjective? Of course. And I admit they can’t do all jobs. The standard usunomi is probably a better general-use paring chisel.
The shinogi usunomi is a serious tool for serious work that looks good while doing it.
Please share your insights and comments with everyone in the comments section below. If you have questions or would like to learn more about our tools, please use the question form located immediately below.
For a change of pace, I would like to share this charming folktale from Kagoshima Prefecture, Japan, of a sort traditionally told to small children.
I have included photo extracts from the Kasuga Gongen Genki E (春日権現験記絵) scrolls painted in 1309 on silk using silver and gold paints, showing carpenters working on the Kasuga Temple jobsite.
My children and I enjoyed this story. Perhaps you and yours will too.
The Tale of Tengo and Tenjin
Long long ago and far far away, there was a very good carpenter. But he was sad because he lived alone.
So he went to the prettiest girl in the village and asked her to be his bride.
She did not want to marry, but to put him off without hurting his feelings, she decided to charge him with an impossible task.
“If you will build me a big house, with 60 tatami mats, in a single day, then I will marry you.” (60 tatami mats = approx 99 square meters = 1065 sqft based on the standard modern tatami mat)
The carpenter was shocked by this demand, but because he wanted her for his bride, he boldly accepted the challenge saying: “I will build you this house in one day.”
His voice rang with confidence, but he despaired in his heart knowing he could not build such a large and beautiful house in one day. He fretted to himself “ what shall I do, what shall I do?”
But never fear, Gentle Reader, because as you have probably guessed, our carpenter was no ordinary fellow to give up easily, and before long he came up with a daring plan.
He made 2,000 dolls out of straw and breathed on each one while casting a magical spell transforming them all into human carpenters.
The carpenter planned the building, and he and his 2,000 man crew went to work.
With the assistance of his 2,000 helpers, the carpenter completed building his bride-to-be’s house before the sun went down that day,
Overjoyed, the carpenter flew to the pretty girl’s house to tell her of his success. “I have finished the house you asked for. Please marry me now!”
“Truly?” she asked. She went to see and found a big, beautiful house with 60 tatami mats, just as she had conditioned. “I will marry you.” she said.
And thus the prettiest girl in the village became the carpenter’s bride.
The carpenter and his bride then moved into their happy new home.
Afterwards, the 2,000 carpenters scattered throughout Japan and for many years taught others how to build houses, temples, bridges and many beautiful things of wood.
After several happy years had passed, the bride said to her husband “I have been silent up to now, but the time has come to tell you the whole truth. I am not really a human being. I am an angel named Tenjin. I came down to earth from the kingdom of heaven. But the time has now come for me to return to heaven.”
The carpenter replied: “Ah, well, now that you mention it, I am not a human being either. I’m a carpenter god named Tengo. Let’s both return to heaven together.”
So Tengo and Tenjin rose high into heaven where they still live together happily ever after.
“A good tool improves the way you work. A great tool improves the way you think.”
The name of the Uchimaru Nomi is composed of 3 Chinese characters (kanji): 内 pronounced “uchi “which means “ inside” or “interior,” 丸 pronounced “maru” which means “round,” and 鑿 “nomi” which means chisel.
This gouge has a blade very similar in cross section to its Western counterpart, but unlike Western gouges, it is made of laminated steel, has the combined tang and ferrule construction typical of Japanese chisels, and a crown to reinforce the handle and protect it from violent hammer blows. These are strong chisels used by carpenters to carve large-scale architectural components, and sculptors.
They come in different sizes and sweeps, although not as many as the Swiss make. Some are the size of typical oiirenomi bench chisels; others are the size of the larger heavy-duty atsunomi.
As you can see, these blades are are not hollow-ground.
The relatively hard layer of steel which forms the cutting edge is often subjected to more lateral forces when carving than their straight-bladed cousins, and are sometimes damaged as a result. Professional carvers will hold the thin cutting edge over a small candle flame to reduce the hardness over a small area to reduce this tendency. I’m not recommending this practice, just conveying information.
The technique used for sharpening Japanese gouges is identical to their Western counterparts. To sharpen the outside bevel, typically one will use dedicated sharpening stones with grooves worn into them that are slightly greater than or equal to the radius of the gouge. One removes the burr and polishes the inside curve by using a short stone with a radiused edge.
A piece of leather charged with polishing compound can be used to put a final polish to the bevel. One can also bend this piece of leather to polish the gouge’s inside surface. Easy peezy.
Standard sizes are 9mm, 12mm, 15mm, 18mm, 24mm, 30mm, 36mm, and 42mm.
There are also uchimaru gouges made as paring chisels, with longer blades and handles, slimmer necks, and without crowns.
If you need a gouge that that can hog a lot of wood, will take an exceptionally sharp edge and will maintain it a long time, then this is a tool you should consider.
In the next post, we will look at a different type of gouge, one you may not have seen before.
“You can complain because roses have thorns, or you can rejoice because thorns have roses.”
This tool is a specialty mortise chisel with two blades for cutting twin mortises at the same time. It was developed specifically for cutting mortise joints in wooden stiles and rails for doors, shoji, cabinets and other joinery.
Interestingly, double or twin tenons are not called ” nihon hozo” (hozo means ” tenon”) but “ nimai hozo “ (二枚ほぞ) with “ni “ meaning 2. In this case the number is combined with the counter “mai “ used to count flat things like a sheet of paper or tenons. Japanese is almost as messy as English… I blame those pesky Buddhist priests for the complications involved in reading and writing Japanese, but I’m not sure who to blame for English.
The name is a variation of the name of the standard mortise chisel ” mukomachi nomi” in my previous post, and no, I still don’t know what it has to do with ” waiting over there.” In front of this is added ”nihon” (二本) with ” ni” meaning ”2” and ” hon” being a counter for longish things, like pencils or trees, or in this case, blades. The word is pronounced ” knee hone.”
Allow me to wander off the path a bit and talk about the Japanese language since you might find a few details interesting. If you don’t feel international today, please feel free to jump over the next few paragraphs.
The nation of Japan is called “Nihon” or “Nippon “ in the Japanese language and is written with the two characters “Ni “ 日 and ”Hon” 本 sometimes pronounced “pon.” Yes, the same pronunciation and one of the same characters used in nihon mukomachi nomi. Besides being a counter for pencils and trees and longish things, it also means ” book” and ” source. ” The word for the nation of Japan means “The source of the sun,” a jab by the Japanese at an arrogant Chinese emporer some millenia ago.
Spoken Japanese is not that difficult for English speakers to figure out, but the reading and writing are crazy difficult because of the vast quantity of Kanji, the multiple pronunciations possible for most of them, and the multiple meanings attached to many.
Elementary children are required to learn 1,006 kanji characters along with the various meanings and pronunciations. In total, a minimum of 4,272 characters are used in newspapers and magazines and must be learned before graduating middle school. Most educated people in Japan can read well over 6,000 of the over 13,000 registered kanji in Japan. Universal literacy requires a lot of study and memorization at a young age. This should give you an idea why education is so highly valued in Japan.
When I was a young missionary in Japan in the 1970’s, I spent several months stationed to Ehime prefecture in rural areas of the island of Shikoku, back when many farmhouses in that locale still had thatched roofs, no glass windows, and no electricty. Many of the older residents had spent their entire lives on their little farms and could not read or write, and had never seen a brown-haired blue-eyed foreigner before.
But the children in these mountain villages were always excited to see a foreigner and would swarm around and ask us where we were from. My standard response to this somewhat rude but innocent question was to point down at each of my legs and count them saying ”One leg, two legs. I’m a Nihonjin.” The “nihon” I was was jokingly referring to was the same as the mortise chisel which is the subject of this post, not Japanese Nationality which is pronounced identically.
Now you know a stupid pun in Japanese, so never say you didn’t get your money’s worth at this blog!
The twin-blade mortise chisel is exceptionally difficult to make, and even new ones require the owner to perform a significant amount of tuning to convince them to perform well. They have never been common, and I am not aware of anyone forging them now.
The twin tenons this chisel specializes in cutting are almost twice as strong as a larger single tenon, and are the preferred joint for high-stress wooden connections worldwide, especially joints in doors and windows. If you haven’t tried them before, you should. They look pretty cool as through tenons too.
Twin tenons have three advantages that justify the extra work. First, while they may have the same or even less cross-sectional area, they have more surface area than a single tenon in the same space, creating greater friction when assembled, if properly cut, creating a joint that is much more likely to stay assembled when stressed.
Second, this larger surface area also means a larger glue area, a big advantage with the right glue.
And finally, twin tenons are much more resistant to twisting, an huge advantage for highly stressed joints in operable doors and windows. This is their biggest advantage and is nothing to sneeze at. If you want a door to last, always use twin tenons, at least at the bottom rail.
I purchased one of these chisels many years ago. They are difficult to tune. But even after all that work, the gentleman I learned tategu work from many years ago was not impressed with my clever tool insisting that a regular mortise chisel does a better job. There is an obscure structural reason why this makes sense, which I will not delve into here, but I did not ask Mr. Honda at the time for an explanation because it would have been improper to question a master who had been a professional joiner at his level for 60 years.
I can’t get these chisels made anymore, and know of no blacksmith that makes them nowadays. The time is not far away when handmade tools will not be available except as collectors items.
“The best investment is in the tools of one’s own trade.”
The next variety of oirenomi we will look at is called the ”shinogi oiirenomi” (鎬追入鑿).
Shinogi (鎬) means ”ridge” as in the angled ridge of a rooftop or mountain. It is pronounced “she-noh-gee.” I believe the word was borrowed from the sword world where it refers to an angled ridge design on the back edge of Japanese swords (shinogizukuri 鎬造り). This detail is used not only in tatakinomi but in tsukinomi as well.
Shinogi oiirenomi are beveled like mentori oiirenomi but are different in that the bevels extend all the way to the centerline of the blade’s face creating a definite ridge. The thickness of the blade’s right and left edges is typically thinner than oiirenomi making it easier to get into tight corners.
I am very fond of this handy, lightweight style of oirenomi and keep a 10pc set mounted to the inside of my toolchest’s lid.
The downside to this design is that the chisel blade loses some stiffness compared to other styles, so they are less than ideal for heavy-duty wood hogging.
Some call these ” umeki” or ” dovetail” chisels. Indeed, some blacksmiths will grind the bevels to a very thin edge for this purpose.
My blacksmiths will not create these thin edges for three reasons: First, shinogi oirenomi are not all that rigid to being with, and thinning the sides further is inviting breakage. Second, warpage is especially difficult to control in thin cross-sections resulting in more rejects and increased costs. And third, people always cut themselves badly using chisels with sides made thin enough to actually fit dovetails. Neither my blacksmiths nor I want that responsibility.
Most umeki chisels do not have the thin sides most people expect.
If you need very thin, sharp sides, you should grind and polish the bevels yourself. Don’t forget to keep a first-aid kit close by, one you can use with just one hand. Seriously.
Shinogi oiirenomi are available in the same widths as oiirenomi.
In the next post I will introduce an old-fashioned but still useful oiirenomi called the “kakuuchi oirenomi.” Stay tuned.