Gihei 150mm Petty. ZDP189 stainless powder steel blade. Keyaki (Zelkova) wood octagon handle with buffalo horn ferrule. HRC 65.
Gihei knives are forged and hand ground in Tsubame Sanjo, Niigata at their small family business. Gihei works with some old style steels like shirogami and aogami and also works with new alloys such as ZDP-189.
ZDP-189 is a tungsten powder steel made by Hitachi with a very high carbon content 3% (!) and a high chromium content; 20%. It can be made very very hard without becoming brittle but Gihei brings this steel to around 65 HRC (it can be hardened to 67...) which leaves their knives with a both good hardness and good sharpen-ability. It holds an edge very nicely and cuts well as it dulls, we were very impressed with this series during our trials.
Handle is Japanese keyaki / zelkova wood, a beautiful densely grained wood often used for fine woodworking. It has a great grip wet and wears nicely.