How is ayasugi hada made?

[piryohae3]

In the book "The Craft of the Japanese Sword" by Leon and Hiroko Kapp and Yoshindo Yoshihara, page 75 states that it's not produced by hammering but by selectively filing away sections at the edge of a masame pattern steel block when the blank for the sword is being formed. 

 

However, http://meiboku.info/guide/form/hada/index.htm says that it is indeed made by varying the strength of hammer blows. These 2 sources contradict each other. Which is correct?

[Ken-Hawaii]

My vote is that ayasugi is simply masame hada that has been distorted.

[Lance]

If I remember it right, it's formed in a similar manner to others types, but at a certain point late in the folding process the smith takes a chisel and punches/dimples the block to embed that warped pattern and continues forging the billet, and when drawing out the length of the blade it's from a different side. (something like top and bottom of block becomes the sides and side becomes top and bottom. As Ken mentions similar to how masame is formed)  

 

Hopefully if I'm too far off someone will step in to correct me. 

 

 

Regards,

Lance

[Jacques]

From Hawley's lamination techniques in Japanese swords  

 

Sunobe also can be twisted and hammered flat.

[16k]

Weird... I remember seeing a different technique in a book but I just can’t reme,ber which book at the moment...

[Ken-Hawaii]

Thanks for that chart, Jacques. I couldn't find it in my references.

[ROKUJURO]

James,

Kapp/YOSHINDO are correct: 'It's ......produced by selectively filing away sections at the edge of a MASAME pattern steel block when the blank for the sword is being formed'. It cannot be produced by making indentations which you hammer flat again, that will not produce a pattern. This method works only if you file the billet after making the indentations.

The whole process is more understandable if you imagine the steel billet as a piece of puff pastry. If you cut this at an angle, you will see the layers. It is no witchwork but mainly experience.