What type of steel is ZDP-189?

ZDP-189 is a stainless knife steel, made by Hitachi Special Steel, Japan. Powder metallurgy yields a fine, uniform carbide structure that improves edge stability and toughness compared to conventional ingot-cast steels. Stainless steels resist rust and require less day-to-day care than carbon steels, but typically trade off some edge retention.

What is the hardness of ZDP-189 steel?

ZDP-189 steel is typically hardened to 63–66 HRC on the Rockwell C scale. Within this range, higher hardness supports finer edges and longer edge retention, while slightly lower hardness gains toughness and ease of sharpening — most premium Japanese kitchen knives target the 60–63 HRC range to balance these properties.

Is ZDP-189 steel stainless?

ZDP-189 contains 20.0% chromium. The conventional threshold for stainless classification is around 13% chromium; steels below that level will discolor or rust under typical kitchen acid/moisture exposure and are classified as carbon or semi-stainless.

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)

A modern steel-making process where the alloy is atomised into a fine powder and then compressed under high pressure before sintering. This creates an exceptionally uniform carbide distribution — far finer and more even than conventionally cast steel. The result is a blade that achieves higher hardness without sacrificing toughness, holds a keener edge for longer, and is more resistant to chipping. PM steels are generally considered a step up in performance, though they can be harder to sharpen on coarse stones. Hitachi Special Steel, Japan 🇯🇵

ZDP-189 粉末ダイス鋼 ZDP-189

Hardness

63–66 HRC

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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

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Steel

ZDP-189

Frequently asked questions

ZDP-189 steel pros and cons for kitchen knives

ZDP-189 is a high-carbon, high-chromium powder metallurgy steel that achieves 63–66 HRC hardness for extreme edge retention, though this same hardness makes the edge more brittle and difficult to sharpen than softer steels.

In the K&S catalog, this steel is used by makers like Hatsukokoro and Sukenari across Gyuto, Petty, and Sujihiki profiles, with prices ranging from $300 to $930 AUD. A concrete example is the Hatsukokoro Hayabusa ZDP189 Migaki Gyuto 240mm, listed at $440 AUD. You should choose this steel if you prioritize holding a razor edge through heavy use and have the skill to maintain a 63+ HRC edge without chipping; if you need a knife that is forgiving of lateral stress or easy to sharpen in the field, the high carbon content and extreme hardness present a trade-off you may want to avoid.

Reviewed by K&S staff · Last updated 7 July 2026

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