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+
白紙3號鋼雖然不如白紙1號或2號鋼那般廣為人知，但同樣是日本高碳鋼家族——即白紙鋼系列中的重要成員。相較於白紙1號（1.2%）與2號（1.0%），其碳含量較低（0.8%），因此硬度稍軟，在使用上也更為寬容。這項特性使其更易於研磨，且較不易崩刃，但鋒利度的維持時間可能不如其高碳含量的同級鋼材。白紙3號鋼非常適合那些嚮往傳統日式刀具極致鋒利度與純淨質感，卻又希望刀身無需過於繁瑣保養的使用者。與其他白紙鋼一樣，它的活性較高，必須妥善照護以防止生鏽與腐蝕。這款鋼材因兼顧了研磨便利性與切削性能而備受推崇，無論是對於初次接觸日本高碳鋼刀具的新手，或是需要刀刃更具耐用度的應用場景而言，都是絕佳的入門選擇。
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+
