Kobelco / Japan

R2

Powder Metallurgy Stainless Steel59–62 HRCPowder Metallurgy (PM)

Composition

Core alloying elements define the baseline trade-off between wear resistance, corrosion behavior, and toughness.

Material Overview

PM Steel, also known as SG2 steel. Apparently Kobelco supplies R2 to Takefu steel, which sells it under SG2 name. Hence the listings of the same knives as R2 or SG2 on different markets. Makers who work with R2 steel in custom knives forge it and different HT process compared with stamped SG2 blades, as such those knives should perform better. Working hardness up to 64HRC.

Performance Radar

Use four core metrics to understand the usable operating envelope of this steel at a glance.

Edge Retention

Toughness

Corrosion Resistance

Sharpenability

Edge Retention

9.0

Toughness

7.0

Corrosion Resistance

9.0

Sharpenability

6.0

Advantages

Excellent edge retention
Very fine grain structure for razor-sharp edges
Good corrosion resistance
High hardness capability
Smooth cutting performance

Disadvantages

Moderate toughness compared to newer PM steels
More difficult to sharpen than basic stainless steels
Higher cost due to premium manufacturing process
Not ideal for heavy impact use

At A Glance

R2 is a high-end Japanese powder metallurgy stainless steel known for excellent edge retention, fine grain structure, and strong cutting performance in premium kitchen and EDC knives.