Thread: Katana-Kagi (swordsmith) asking for input

Hello all,
Actually this is the beginning of my first post on this forum on another tread.

Since I am new here and this is my first post let me introduce myself. I am a bladesmith in Texas working in the Japanese tradition. I concentrate on swords (Katana, Wakazashi, Tanto etc.) But I have also done extensive work making woodworking planes.

I am a complete newbie to straight razor shaving and I am certainly no expert on kamisori but I am working on making some kamisori and would like some input on what I know of crafting Japanese style blades and how kamisori may be similar or different.


Kamasori, like almost all quality Japanese plane irons, chisels and many knives have a high carbon, hardenable steel insert forge welded to a low carbon soft steel or iron body.

The argument that this saves the expensive steel for where it is needed is a good one. In times past, producing high carbon steel was time consuming and expensive proposition.

There are other considerations as well, Having a soft steel substrate allows the cutting edge to be harder. The harder the steel the more prone it is to chipping-like glass. The soft steel or iron can help absorb and dissipate the forces that may otherwise chip the blade.

After perusing many pages here and other sites I would say that a kamisori can be most likened to a plane blade. A katana is a much more romantic implement but it is meant for slicing through flesh and bone while at the same time being able to absorb the stress of combat.

A plane blade is designed for shaving wood. Much as a kamisori is designed for shaving hair.

One of the essential elements of a fine plane blade is a flat and polished back (Ura). The front (omote) side of the plane blade has a bevel. The angle of the bevel is governed by two constraints. A sharper angle allow the blade to penetrate the wood easier. A more obtuse angle makes for a stronger blade.

Once the ura has been flattened and polished very little time is spent honing it later. 80-90% of the honing takes place on the omote bevel with the rest being used on the ura to simply help remove the wire edge.

I see the same on a kamisori. Now the Ura may not look like a flat plane, but it is. The hollow is simply there as clearance and to facilitate a thinner edge. The important flat part is right at the edge.

The most important angle is the angle of the back(ura) to the wood being plane. This is determined by the angle that the blade is bedded in the plane body. Hardwood planes are usually set at around 45 degrees softwood around 40 degrees.

The bevel angle on the omote side cannot add up to 90 degrees. That is, if the blade is bedded at 45 degrees the omote bevel angle must be less than 45 degrees, usually way less or it will never cut. The bevel will ride on the wood never letting the edge dig in.

A well tuned plane with a quality blade will sever the wood cells so that they refract light. A much more appealing finish than sandpaper and coats of varnish.

So,
How much of what I said above relates to a kamisori? What may be unique to a razor that does not correlate to shaving wood?

Any input would be appreciated.

Dan O'Connor

I'd say the angle of approach to the beard does not have anything to do with thickness of the hair, but more with the direction of the hair growth.
Obviously the bevels of the Kamisori meet at much smaller angle than a plane blade bevels.

If you have made plane blades, then a razor shouldn't be too bad. All you can do is give it a whirl and see. I'm not sure if you are making your own steel, but there are many western style razors made of the tool steels like O-1 & A-2 that I'm sure would work well as a kamisori as well.

Thanks for the input guys.

I have access to Aogami or Japanese blue steel and some old wrought iron. I will forge weld these together as well as using some monosteels as well to compare.

I have zero technical knowledge or skills, but this is a super interesting read and please keep the updates comming!

Hello Dan, Welcome to SRP. I hope you'll like it here.
I am always glad to see traditional craftsmen show up. I don't have a kamisori, so unfortunately, I cannot help you.
Your explanation sounds correct, though we have some people who know kamisori in great detail. No doubt you will get detailed answers in a short while.

I know this is perhaps not going to be directly relevant to your question, but it might be interesting in some other way: some people like kamisori style razors but don't like the ura / omote design. For such people, custom makers have made kamisori style razors with a symmetrical grind.
Here you can find pictures of the one made for me by one of our members
http://straightrazorpalace.com/strai...-straight.html

Welcome to SRP Dan. I'm moving this thread from 'razors' to 'workshop' where other razor makers are more likely to see it and respond.

Welcome! I am watching for more input from you!

welcome and subscribing to this thread....

Dan, I would imagine that using a Kamisori would answer most of your questions in regards to angles and design. A kamisori made by an experienced smith, that is. Henkotsu, Tsurayuki, Iwasaki, et al.

I can tell you, the blade angle of a Kamisori is far more acute than any plane blade.

Also, in terms of Hitachi steel only Shirogami ever seems to be used by razor makers. I have it on good authority (the best, perhaps) that for razors, Swedish Assab steel is superior to White or Blue steel.

Just my two cents.