日立特殊鋼，日本
白三鋼 / 白紙三號 White #3 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.
59–61
HRC
555759616365+
白鋼3號（White Steel No.3）雖然不像白鋼1號或2號那般常被提及，但也是日本高碳鋼家族中的一員，屬於白紙鋼系列。碳含量較低（0.8%），相比白鋼1號（1.2%）與2號（1.0%）更為軟韌，因此在使用時容錯性。這特性更容易研磨，且較不易崩口，但相對而言，鋒利度保持時間可能不如高碳含量的白鋼。白鋼3號適合追求傳統日本刀細膩刃感與純粹質感，卻又希望刀身維護較為輕鬆的。如同白紙鋼材，它極活性，需妥善保養以防止生鏽與蝕。此鋼種研磨容易與性能之間的良好平衡而備受推崇，是初學高碳日本刀或需要更耐用刃口應用的理想門選擇。
成分
白三鋼 / 白紙三號 元素組成
比較對象
白三鋼 / 白紙三號
—
0.8%
0.6%
0.4%
0.2%
0
C
0.8%
Mn
0.2%
Si
0.1%
P
0.025%
S
0.004%
C — 碳
Mn — 錳
Si — 矽
P — 磷
S — 硫
硬度
59–61 HRC
555759616365+
