Takefu Special Steel, Japan 🇯🇵
COSP (Cobalt Special) Cobalt Special 鋼
硬度
洛氏硬度(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.
60–62
HRC
555759616365+
Takefu Special Steel 的 Cobalt Special 鋼（常稱為 Cobalt Steel）是一款高階高性能鋼材，以其卓越的保持性和硬度聞名。此鋼種含有相當比例的鈷元素，顯著提升了耐磨性與強度。透過添加鈷，以及碳、鉻、鉬等其他元素，使鋼材能在不犧牲韌性的前提下達到高硬度。Cobalt Special 鋼能長時間維持鋒利，即使在高強度使用下亦表現優異，因此極受高端廚刀與切割工具製造商的青睞。
如 Mojin 與 黑崎 等名家，均有推出極具代表性的 COSP 系列產品。
如 Mojin 與 黑崎 等名家，均有推出極具代表性的 COSP 系列產品。
成分
COSP (Cobalt Special) 元素組成
比較對象
COSP (Cobalt Special)
—
16.0%
12.0%
8.0%
4.0%
0
C
1.05%
Cr
16.0%
V
0.25%
Mo
1.5%
W
0.25%
Co
2.5%
C — 碳
Cr — 鉻
V — 釩
Mo — 鉬
W — 鎢
Co — 鈷
硬度
60–62 HRC
555759616365+
