when to grind the Uraoshi(back hollow grind)

[Danjmath]

I am trying to make a Yanagi-ba(sushi knife) for the first time.

I've got the blade rough-ground and heat treated, and am trying to decide if I should do the flat grind or hollow grind first.

I would guess the flat to an almost finished state, but I'm afraid when I try the hollow on the back I'm going to mess it up and have to regrind.

The all powerful search tool seems to have failed me for the first time on the "when" of this kind of grind, although I have a different methods on the "how".

Any advice would be appreciated.

 

 

[templehound]

Making single bevel knives like a Yanagi ba is really tricky because of its tendency to bend while it is heat treated , especially when its hardened.

Keeping it from bending towards the unbeveled side is more concerning than grinding the hollow on the flat side .

So if You have a blade that will bend to the "weaker" side, You should not weaken the side even more due grinding it hollow.

So it seems better to grind the hollow after HT, but I know two professional Japanese cutlery makers and they make it contrary. 

I would grind it after hardening,  ....together, reciprocally with the beveled side

It strongly depends on the parameters of the blade in length, thickness, mono steel or two layers etc, how Your blade will behave....You have to try that out and prepare to regrind or throw it in the trash can.....

this guy does a great job, look at 4:20 ,...maybe this will inspire and help

https://www.youtube.com/watch?v=wrphlV9mEa8

Cheers and good luck