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. 日立特殊鋼，日本
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. 日立特殊鋼，日本
HAP-40
Hardness
Rockwell C Hardness (HRC) measures how resistant a steel is to permanent deformation. For kitchen knives:
55–58 HRC — Soft. Easy to sharpen and forgiving of rough use, but dulls faster. Typical of most German knives.
59–61 HRC — Balanced. Good edge retention with manageable sharpening. Common in mid-range Japanese knives.
62–64 HRC — Hard. Excellent edge retention, holds a very fine edge. Requires more care and a fine stone to sharpen.
65+ HRC — Very hard. Exceptional edge longevity but more brittle — more prone to chipping if used roughly.
Higher is not always better — it depends on how you use and maintain your knife.
55–58 HRC — Soft. Easy to sharpen and forgiving of rough use, but dulls faster. Typical of most German knives.
59–61 HRC — Balanced. Good edge retention with manageable sharpening. Common in mid-range Japanese knives.
62–64 HRC — Hard. Excellent edge retention, holds a very fine edge. Requires more care and a fine stone to sharpen.
65+ HRC — Very hard. Exceptional edge longevity but more brittle — more prone to chipping if used roughly.
Higher is not always better — it depends on how you use and maintain your knife.
64–68
HRC
555759616365+
HAP-40 鋼是一種以極佳持久度和耐用性著稱的高速工具鋼，非常適合用於廚刀。其硬度最高可達 68 HRC，即使長時間使用也能維持鋒利。由碳、鉻及鎢、釩等元素組成，兼具硬度與韌性，降低缺口崩裂風險。優異的耐磨耗性確保長效表現，但因為其硬度較高，研磨 HAP-40 鋼可能需要進階工具。這種鋼材非常適合注重切割效率與低維護需求的使用者。
Composition
HAP-40 Element Composition
Compare with
HAP-40
—
8.0%
6.0%
4.0%
2.0%
0
C
1.3%
Cr
4.0%
V
3.0%
Mo
4.8%
W
6.0%
Co
8.0%
C — Carbon
Cr — Chromium
V — Vanadium
Mo — Molybdenum
W — Tungsten
Co — Cobalt
Hardness
64–68 HRC
555759616365+
