Stainless Stainless Steel

"Stainless" means stain-resistant, not stain-proof. In kitchen use, the steel can still discolour or pit if exposed to acidic environments — citrus, vinegar, or salt water — for extended periods. Wash and wipe dry after every use, and avoid leaving the blade soaking in water. With basic care, a stainless knife is very low-maintenance and a great everyday choice. PM / Powder Steel Powder Metallurgy (PM)

PM stands for powder metallurgy. Fine steel powder is consolidated under heat and pressure. This can produce a fine, even carbide structure, but performance still depends on the steel and its heat treatment. The PM label alone does not guarantee a harder, tougher or more chip-resistant knife. Hitachi Special Steel, Japan 🇯🇵

ZDP-189 粉末ダイス鋼 ZDP-189

Hardness

63–66 HRC

555759616365+

ZDP-189 steel is a high-end powdered metallurgy stainless steel renowned for its exceptional hardness and edge retention capabilities. Developed by Hitachi Metals, it contains a high carbon and chromium content, allowing it to achieve hardness levels up to 67 HRC, making it one of the hardest steels used in knife making. This extraordinary hardness means that ZDP-189 can be sharpened to a very fine edge and maintain that sharpness through extensive use, far surpassing many other steel types in terms of edge retention. However, its high hardness also means that it can be more challenging to sharpen and may be more prone to chipping if used improperly. ZDP-189's significant chromium content also provides it with a degree of corrosion resistance, though care should still be taken to maintain the blade. Due to its premium qualities, ZDP-189 is often used in high-end and specialty knives, appealing to enthusiasts and professionals who prioritize cutting performance and longevity.

Compare with

ZDP-189

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20.0% 15.0% 10.0% 5.0% 0

3.0%

20.0%

0.1%

1.4%

0.6%

0.5%

0.4%

C — Carbon Cr — Chromium V — Vanadium Mo — Molybdenum W — Tungsten Mn — Manganese Si — Silicon

Hardness 63–66 HRC

555759616365+

Steel

ZDP-189

What's in ZDP-189

What each element does in your knife.

ZDP-189 element composition and spec ranges
Element	Spec range	What it does in your knife
CrChromium	20.0%	Raises corrosion resistance; at roughly 13%+ free chromium the steel qualifies as stainless. Also improves hardenability and wear.
CCarbon	3.0%	The primary hardening element. More carbon means a harder edge that holds longer — but past a point it trades away toughness and rust resistance.
MoMolybdenum	1.4%	Improves hardenability and toughness, boosts corrosion resistance, and helps the steel hold hardness under heat.
WTungsten	0.6%	Forms hard carbides for wear resistance and edge stability, and keeps the steel hard even at elevated temperatures.
MnManganese	0.5%	Aids hardenability and strength and acts as a deoxidiser in smelting. Too much can reduce toughness.
SiSilicon	0.4%	Strengthens the steel matrix and acts as a deoxidiser, improving hardness and resistance to oxidation.
VVanadium	0.1%	Forms extremely hard vanadium carbides for superior edge retention, and refines the grain for a finer, tougher edge.

Composition from zknives (K&S steel dataset) reference material. These ranges come from the K&S steel composition dataset, which is derived from zknives; maker figures are cited separately only when they are used on the page.

Frequently asked questions

ZDP-189 steel pros and cons for kitchen knives

What the research shows

ZDP-189 is a powdered-metallurgy stainless steel from Hitachi Special Steel with roughly 3% carbon and 20% chromium, routinely hardened to 63–66 HRC — among the hardest kitchen-knife steels in production. Its pros are exceptional edge retention, the ability to take an extremely fine edge, and stainless-class corrosion resistance. The cons are equally well documented: it's slow and difficult to sharpen, the extreme hardness makes edges more prone to micro-chipping under twisting or lateral loads, and the knives cost more. Market consensus treats it as a specialist steel for experienced users who prioritise long edge life over easy maintenance.

The Knives & Stones take

Honest answer: I wouldn't want to sharpen a ZDP-189 knife myself — the feedback on the stones is just weird, and with 3% carbon and 20% chromium it's slow, stubborn work. So here's my rule: unless you absolutely require the longest edge retention money can buy, look at SG2/R2 or SKD instead. Both run 62–64 HRC, hold an edge well beyond VG10, and are dramatically easier to sharpen and touch up. That said, if edge life is genuinely your top priority, ZDP-189 at 63–66 HRC is the real deal, and we carry it from two makers I rate: Sukenari and Hatsukokoro. The Hatsukokoro Hayabusa ZDP189 Migaki Gyuto 240mm ($440 AUD) is the one I'd point you to — just budget for diamond stones.