What type of steel is SG2 / SG2粉末HSS / R2?

SG2 / SG2粉末HSS / R2 is a 不鏽鋼 knife steel, made by Takefu Special Steel, 日本. Powder metallurgy yields a fine, uniform carbide structure that improves edge stability and toughness compared to conventional ingot-cast steels. Carbon steels can take an exceptionally fine edge but require thorough drying after use to prevent rust and discoloration.

What is the hardness of SG2 / SG2粉末HSS / R2 steel?

SG2 / SG2粉末HSS / R2 steel is typically hardened to 62–64 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 SG2 / SG2粉末HSS / R2 steel stainless?

SG2 / SG2粉末HSS / R2 contains 14.0% 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.

PM / 粉末鋼 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. Takefu Special Steel, 日本

SG2 / SG2粉末HSS / R2 Super Gold 2 鋼

硬度

62–64 HRC

555759616365+

SG2，又稱 Super Gold 2 或 R2，是由武生特殊鋼生產的高階粉末工具鋼，以卓越的鋒利度保持性、耐磨性，以及最高可達 64 HRC 的硬度聞名。其規格與神戶製鋼所的 R2完全相同，因刃口極致鋒利且耐用度高，備受頂級刀具製造界推崇。得益於粉末冶金工藝，碳化物分佈均勻，不僅提升了韌性，更有效降低崩刃風險。對於追求切削工具頂尖性能與長久耐用的使用者而言，SG2／R2絕對是理想首選。

比較對象

SG2 / SG2粉末HSS / R2

—

14.0% 10.5% 7.0% 3.5% 0

1.25%

14.0%

1.8%

2.3%

0.4%

0.5%

0.03%

C — 碳 Cr — 鉻 V — 釩 Mo — 鉬 Mn — 錳 Si — 矽 P — 磷 S — 硫

硬度 62–64 HRC

555759616365+

鋼材

SG2 / SG2粉末HSS / R2

類別

不鏽鋼

製程

Powder Metallurgy (PM)

製造商

Takefu Special Steel, 日本

硬度

62–64 HRC

Frequently asked questions

Knives and Stones 岩刃社的SG2鋼刀具

對於想要擁有不鏽鋼刀具，卻追求碳鋼般優異性能、又不想費心保養的朋友，SG2 鋼向來是我的首選推薦。憑藉 1.25% 的含碳量與 HRC 62-64 的硬度，它不僅能磨出極致鋒利的刃口，保鋒力更是遠勝 VG-10 或 AEB-L，同時具備完全的防鏽能力。這把刀讓您魚與熊掌兼得：既無需擔心氧化變色，又能享有貨真價實的切削性能。

SG2鋼與AS鋼製作廚刀——哪種更勝一籌？

兩者並無絕對優劣，端看您更重視不鏽鋼的便利性，還是碳鋼極致鋒利的切削手感。若您希望刀具能長時間維持極致鋒利且無需費心保養，SG2鋼會是理想選擇；若您追求極致的薄刃與切割性能，且不介意每次使用後都仔細擦拭刀身，那麼 AS 便是您的首選。

SG2 鋼是來自武生的粉末不鏽鋼，硬度通常落在 62-64 HRC 之間。它兼具韌性與優異的抗腐蝕能力，因此每當處理酸性食材時，我總會優先選用這把刀。超級青鋼屬於高碳鋼，硬度通常較高，約在 64-66 HRC。它能磨出極致鋒利、足以削髮的刃口，鋒利度的維持性也略勝 SG2 鋼一籌，但若疏於保養便容易生鏽。

R2 鋼與 SG2 — 它們是一樣的嗎？

是的，R2 和 SG2 是同一種鋼材——R2 是神戶製鋼所使用的名稱，而 SG2（Super Gold 2）則是武生特殊鋼對相同粉末冶金配方的稱呼。型錄證實了這一點：SG2 / R2 是來自日本武生特殊鋼的粉末（PM）鋼，成分為 1.25% 碳、14.0% 鉻、1.8% 釩、2.3% 鉬，硬度範圍為 62–64 HRC。因此，如果您看到標示為 R2 或 SG2 的刀具，您獲得的將是完全相同的材料。

Reviewed by K&S staff · Last updated 22 July 2026

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