Chefknivestogo exclusive! Kohetsu HAP40 knives appeal to the performance customer that wants unmatched edge retention. HAP40 is a semi-stainless, powdered high-speed steel that takes and holds an edge better than any other steel available on our site. It's proven to be one of the best steels on the market for the production of high-quality kitchen knives. Hitachi manufactures this steel and it contains abundant amounts of hard elements like tungsten, molybdenum, vanadium, and cobalt. Heat treated at 65-66 HRC and you will find this blade will hold its edge for an amazingly long time.