Nippon Koshuha / Japan

OU-31

Stainless Steel59–61 HRCConventional Ingot Steel Process

Composition

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

Material Overview

OU-31 is a Japanese stainless steel produced by Takefu Special Steel, designed for cutlery applications requiring balanced overall performance. It provides a fine grain structure that supports keen edges, reliable corrosion resistance, and good toughness. The steel is appreciated for its smooth sharpening characteristics and practical balance between durability and cutting performance, making it suitable for both professional and everyday knife use.

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

8.0

Toughness

8.0

Corrosion Resistance

8.0

Sharpenability

8.0

Advantages

Fine grain structure for sharp edges
Good corrosion resistance
Balanced toughness and hardness
Easy to sharpen and maintain
Reliable everyday cutting performance

Disadvantages

Edge retention lower than premium PM steels
Moderate wear resistance
Less suited for extreme hard-use applications

At A Glance

OU-31 is a balanced Japanese stainless steel offering good sharpness, corrosion resistance, toughness, and ease of sharpening, commonly used in quality kitchen and utility knives.