Thread: grind a oiire nomi to a usu nomi?

Originally Posted by lignator

It is hard to find any usu nomi (paring chisels) on ebay or the like. But oiire nomi (bench chisels) are all over the place.

Since a majority of the thickness in a oiire is the softer iron, is it possible to just grind back about half the thickness and replace the short ringed handles with longer native hardwoods without a ring?

I guess you'd loose the makers mark, but the original value will be shot by the modification anyway. I've heard that some people grind back a oiire to a dovetail. Has anyone here tried the dovetail mod or the mod I'm suggesting?

Thanks ye,
lignator's first post.

Hi lignator,

I can get you anykind of chisels, including usu-nomi, dovetail shaped nomi (bachi-nomi), etc. If you are interested, you can tell me what you are using it for, and your budget, and I can tell you my recommendation.

Regarding the modification, there's a chance you might end up with a warped blade chisel (it'll probably warp to the steel side). Japanese laminated chisel is balanced with the thickenss of the iron and the steel, so once the balance is broken you don't know what's gonna happen. The tension between the iron and the steel is quite different, so this balance is very important. Usu-nomi usually has a very thinly laminated steel, and the back hollow fixed after the hardening (ie not black hollow. Thus black hollow usu-nomi is rare.)

It might be okay to try this modification if your oiire is a super cheap one, but if it's a good one, I wouldn't do it. If you over do it it might not just warp but snap.

Cheers

Thanks soatoz!

Changing the balance and weakening the structure were on my mind as two potential risks. Based on your input I will likely not go down the path described in my post.

Thanks for sharing some of your knowledge on this forum. I've learned more from a few dozen posts here than I have after reading hundreds of posts on other ww and tool forums.

rick

Rick

I modified a firmer into a dovetail. This was successful - no warping. I did avoid grinding the hard steel and kept it to the backing.

Hi Soatoz

The mortice gauge arrived safely today ... plus your wonderful gift! You are very generous. Thank you.

I am interested in a couple of bachi-nomi as paring chisels, so ideally long handled ones. (12, 18, 24 mm). Please contact me on my email: [email protected]

Regards from Perth

Derek