Shigefusa 270mm kasumi yanagiba with custom, by me, desert ironwood handle

22 Oct 2011

Honyaki Gyuto 240mm refurbishment

I got this gyuto blade a while ago. It is a 240mm honyaki blade, made from Shiro-ko #3 steel and it is oil quenched. Shiro-ko #3 is very rarely seen used in knives. It is identical to Shiro-ko #1 except it has 0.8%C instead of 1.3%C in Shiro-ko#1. It is thus a very delicate blade with exceptional capabilities regarding hardness and ability to take an ultra sharp edge. As the toughness of the steel is low, it is a blade for the finer work in the kitchen where an exceptionally sharp and a wear resistance edge is required. From the two charts below you can see the striking similarity between the Shiro-ko #3 and the Shiro-ko #1. If anything the Shiro-ko #3 appears to be an even purer steel than the #1.

Steel composition chart for Shiro-ko #1 (from

Steel composition chart for Shiro-ko #3 (from

The blade is originally an OEM blade made in Seki, Japan. Rumors has it that two previous owners/ knife makers has thinned and reshaped the blade on a belt grinder, thus removing the kanji, but both makers finally abandoned it for unknown reasons. Finally it ended up at my friend Øivind's house and as Øivind didn't seem too keen on the blade either, he traded it with me for a new handle on one of his new knives. Hopefully he won't regret that too severly when he sees the finished knife.

The blade didn't look like much when I got it, but I needed a project and anticipated there could be quite some potential in this blade, so I gladly accepted the challenge.

The grind marks were quite pronounced and I didn't like the profile of the kissaki so the first thing I did was to reshape the tip by lifting it a little bit. That balanced the blade and made the profile more to my liking.

You can see the very pronounced grind  marks. Hamon just visible.
The next thing was to polish the blade and rounding the choil and spine. That shoud prove to be a longer and more work intensive project than I first expected. I started out with some pieces of old synthetic stones. #220, #700, and #1000. Then I switched to Japanese natural finger stones. First Iyoto, then Aka pin and finally uchigumori. The steel in this blade is exceptionally wear resistant, so the process from #220 to the final polish took me around 25 hrs and wore down a lot of stones and finger tips. After this long and bloody process the finish on the blade looked like this. When I saw it I instantly forgot my sore fingers. It was a beauty of  a blade! Maybe just because it was now thoroughly baptized in my own blood.
A beautiful  wavy hamon on the polished blade. I just love my JNAT fingerstones.
So, I had this beautiful honyaki gyuto blade on my hands. Now what? It really deserved a nice handle and saya. I had just gotten in some beautiful redwood burl luthier wood and I had a couple of very nice stabilized redwood burl blocks from Burl Source in my knife shop. I didn't take any WIP pics of the handle and saya making as my camera was in another location at the time. I hope the pictures of the finished project speaks for itself.
When I got the raw blade and saw the grind marks from the belt grinder I was afraid that the heat treat might be destroyed. When grinding down the blade I realized that the heat treat was very much intact, and the first sharpening sessions on the finished knife have resulted in an exceptional edge. I now have this beautiful honyaki gyuto in my collection. Thanks to Øivind who traded me the blade and thanks to Mark at Burl Source for his exceptional handle materials. They are a joy to work with.


  1. Nice work Harald !!!
    Like always :)
    My hands shaking every time i go to Burl Source website

  2. Excellent saya, especially for the fact that burl is rather difficult to work due to its grain. Kudos.

  3. Thanks. Yes the burlwood is pretty tricky to work with. The redwood wasn't too hard but the density of the burls required very sharp chisels and baby steps all the way when working the cavities. Working the outside, however, was a breeze as it takes sanding very well.

  4. Wow--what a stunner! The part about lost fingertips was a bit cringe-inducing, but the results seem to have been worth it!

  5. Hey Darkhoek. I've been meaning to ask you but where in the world did you get the redwood burl from? I'm on the hunt for some because I'm looking to have a saya made for my 270 kono honyaki and I'm thinking that it would look really good with that kind of wood. Would have shot you off an e-mail but dont think I ever asked you for it. Wonderful job. :)

  6. Hi Aaron. Sorry for my late reply. Both the stabilized burl for the handle and the unstabilized wood for the saya I got from Mark at Burl Source.
    Regards, Harald.