Every few years Sukenari works a steel nobody else has bothered with. ZDP-189, HAP40, SRS-13, YXR7, and now ZDP-247. It is not a new alloy. It comes from the same Hitachi (now Proterial) ZDP family as ZDP-189. Murray Carter was working a ZDP-247 variant back in the early 2000s, and described it as a steel made for forging rather than grinding from a blank. The steel came out of Hitachi about thirty years ago, and Sanyo Riki, the mill that laminates Sukenari's billets, says roughly a ton of it is left. What is new is a production kitchen series, which Sukenari debuted in August 2026. As far as we can tell, we are one of the first shops anywhere to sell commercially available ZDP-247 kitchen knives from a reputable maker, and possibly the first.

Now the honest part. Sanyo Riki calls ZDP-247 a development grade, and the only thing we have been told about it is one line: powder stainless, heat-treat it like SRS-13. Proterial has never published a specification at all. So we cannot give you a carbon or chromium figure, because nobody outside Proterial has one.

What we can give you is how it cuts. Sukenari takes it to 63 to 64 HRC, a touch under where they run ZDP-189. It is a hard powder steel and it holds an edge like one: a long plateau, then a clear signal that it wants the stones. The surprise came on the stones themselves. We put the 247 and the 189 on the same ones, and the 247 gives up a burr without the fight. It still rewards a good stone. It is stainless on paper. So is ZDP-189, and that still spots if you leave it wet. Wipe it, keep it dry, and do not twist it through bone.

This is the Hairline: a stainless-clad san-mai with the ZDP-247 core between softer stainless layers, brushed rather than mirrored. Same construction and finish as the ZDP-189 Hairline that so many of you own, so the feel in hand and the thin grind behind the edge will be familiar. If you own the 189 and want the next chapter, this is it. If you are new to steels this hard, start with the ZDP-189 Hairline and come back for this one.