Utsuri

[Kanenaga]

Can anyone recommend a book (or website) about utsuri? Ideal would be a discussion about the different types, with examples, and something about the metallurgy.

 

Bizen style utsuri. Osafune Kagemitsu tachi.

Photo by Darcy Brockbank. Copyright Darcy Brockbank estate.

[SteveM]

Here's something about the metallurgy.

https://markussesko....-thoughts-on-utsuri/

[Mark S.]

From Usagiya.  Some good info.

 

http://www.ksky.ne.jp/~sumie99/utsuri.html

[Franco]

Yamanaka's Newsletters revised talks about and describes various forms of utsuri. 

 

 

[Apercus]

I don’t disagree with any of the posts here.  All seem to be good ideas and well thought out. I haven’t seen a thorough analysis of the metallurgy of utsuri. It would have to be comprehensive because not everything we call utsuri is the same micro structure or at least that’s my opinion. Banite formation is one of the results that we call utsuri. It forms at a different temperature than martensite and can be produced without clay. The heat is introduced at the edge of the blade and is not allowed to spread across the full width before quench. Imagine holding a blade edge against a heated block of steel to transfer heat to the blade. Quench before the heat travels uniformly across the width. The band of banite will appear seperated from the martensite.  
I have found that not all steels will produce this effect. Low allow and mid to low carbon content works best for me. I haven’t done anything comprehensive in testing many allows so I’m speaking from limited first hand experience. Think about the effect you see on a blade damaged in a fire and then reheat treated. The whitish band between the nakago and the blade which is an indicator of reheat treatment is the same thing as some of the effects we call utsuri. 
if you want to test this yourselves take a bar of low allow medium to low carbon steel (something like 1045 steel) and heat the tip of one end. Quench and then polish it. 

 

[Kanenaga]

Thanks Mark and Franco. 

Shannon, I seem to recall some discussion(s) about the metallurgical aspects in the remote past, but not sure how to track them down. 

[The Blacksmith]

A book that I can highly recommend is Cutting Edge, by Victor Harris.  The Book deals with 99 blades from the collection of the British Museum, from the Kamakura period to the Meiji era. Apart from giving details of some absolutely beautiful blades, Victor was regarded as a leading authority on the Japanese sword, and in addition, he was also an engineer, so has a very easy way of describing the various techniques, features and traits of the blade. Not as indepth as the Connoisseur's book of Japanese Swords, but easy to read and extremely interesting and informative.

Highly recommended.

 

 

 

Cutting Edge

[Toryu2020]

Check The Craft of the Japanese Sword page 91.