Sharpening a Sujihiki

[5698k]

I just got my first sujihiki, a Konosuke HD2 300mm. It’s a beautiful knife, used, but not as sharp as I would think. Is there a different protocol for sujihikis? Or are they sharpened like any other knife as far as sharpness?

 

[lemeneid]

Go through the same motions with a suji as you would with a gyuto. They aren’t single bevels but you just need to get used to the extra length that’s all

 

[mikaelsan]

i try to put a slightly lower grit on mine, compared to what i like on a gyuto, as mine is primarily used for carving meats with crust, as it will easier bite into the crust. but usage and opinions may vary

 

[Rosco]

^
I'm going to try this with my suji (Fujiwara FKM). I do a fair bit of barbecue and had been considering buying a Tojiro ITK bread knife for slicing even though I almost never cut bread!

 

[Benuser]

Try a big jump, say 400-4k or so.
Or use finer stones than the first one only for very light stropping and deburring, and the finest for deburring only.

 

[masibu]

I keep mine a little coarser personally to deal with anything crustier but theres no harm in polish for more delicate slicing. I have a hd kono gyuto which I've been playing around with recently and around 1200-2000 is nice and aggressive for a finish on cooked product. If you want a higher polish I feel like its diminishing returns after a 4000 although I have finished it on a snow white (until it broke anyway) and other finer stones. This is generally just a micro bevel of sorts if you do take that approach. Polish wont hold up that well against anything crusty though.

 

[masibu]

^
I'm going to try this with my suji (Fujiwara FKM). I do a fair bit of barbecue and had been considering buying a Tojiro ITK bread knife for slicing even though I almost never cut bread!

The fkm appreciates a coarse edge for sure being a softer stainless blade. 600-1200 grit to finish should sort it out as long as you keep your angles low. Coarse stones don't respond as well to high angles and you will lose aggression in the cutting.

In the case of this knife theres little advantage to polishing any higher than that as you will lose that aggression pretty quickly. I've taken aus 8 to sigma 6 and a shapton 5 polish and whilst the push cutting is nicer it loses that bite it had at the lower grits. 3k finish max unless you want to keep touching it up regularly. Carbon steel and harder stainless are better reserved for higher finishes (including a 3k finish) though. Aus 8 is in it's element with a 700 grit or so finish for slicing.

 

[kkat]

Try a big jump, say 400-4k or so.
Or use finer stones than the first one only for very light stropping and deburring, and the finest for deburring only.

While my jump isn't as wide as Benuser's suggestion, a 320 to 2k progression works well for breaking down sub-primals into steaks to cutting through crusty roasts. I use this progression on my vintage Misono Swedish sujihiki (330mm, ~hrc61*) and a Masahiro VC hankotsu (150mm, ~hrc62-3*). Sometimes I'll lightly strop and/or deburr on an 8k or 12k Shapton Kuromaku.

*The hardness estimates are from testing with Tsubosan hardness files.