Machi

Hi all. I wanted to ask if someone can help me understand the machi?

 

On traditional Japanese knives, the tang is burnt into the handle, not glued or epoxied, as the handle is meant to be removed to allow the blade to be polished. Each time the handle is reinstalled, the tang is driven in a little more. The machi is simply the amount of tang remaining that can be driven into the handle before a new handle must be used.

If the tang is glued or epoxied into the handle, there is no reason to leave a machi, unless you are trying to mimic the traditional appearance of a burnt in handle.

Note that uneducated Western sensibilities tend to regard any knife with a machi as poorly finished.

 

Thanks Rick. Very good info.
I waver on the machi as a traditional feature which is why I ask. It has a practical purpose and that's what I wanted to understand.

 

Technically, the machi is just the step in width from neck to tang. Even with no visible gap present, a machi still exists on many blades (particularly single bevels and some regional double-bevel styles like in Sakai).

I believe the original question and Rick's answer were both speaking to the idea of gap rather than step, but I thought it would be good to clarify a bit on the word itself.

 

Hmm. Gator (zknives.com) Defines the machi as "Narrow section of metal between the notch at the end of the neck of the blade - L on the Diagram, emoto(K on the Diagram) and the handle, approximately 5mm long."

Does that not mean that if the handle is flush to the end of the emoto, there is no machi?

 

I'll tell you what I was wondering about regarding the machi.
I've worked primarily in AEBL until recently, and now do mostly 52100 carbon.
My concern was whether there might be a danger of rust or corrosion if the shoulder meets directly with the handle.
If this were true the machi would make sense in eliminating the issue. I have a lot of respect for the traditional ways of Japanese makers.
There are usually traditions for good reason. Sometimes the reason can change over time.
In this case, resin epoxy probably mitigates the concern.

But I had to ask....

 

The zknives definition has come up before, and it is not how most Japanese craftsmen use the term. I brought the same thing up on the other forum when JKI announced the machi series in the Kochi line.

 

Thanks for the clarification. Was I at least correct on the purpose?

 

I'm not an expert on kitchen knife construction but as far as I know, your explanation of function was correct. It also allows some adjustment if the handle loosens slightly from compression in the tang slot or expands from environmental conditions. It also seems to inform other knife design styles that do not use machi (i.e. a fluid tang-neck transition), in addition to the relative simplicity of forging.

As a rust point, it seems reasonable but I haven't heard or read anyone providing that rationale in Japanese. Of course as I said, I can't claim expertise.

 

My understanding of the Machi is the same as Robert's, it's the step from the emoto to the tang. When you have a traditional install and a gap is left between the emoto and handle, for the reasons Rick pointed out, then you have an "exposed Machi". If the handle is fit tight to the emoto you have a "hidden Machi". Just another explanation for what you guys already said. I've also heard an exposed Machi or traditional install referred to as "Tokyo style".