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 zknives.com)



Steel composition chart for Shiro-ko #3 (from zknives.com)











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.