SUS440C Stainless Steel: High-Hardness Cutlery Grade Guide

Key Characteristics

High Hardness: Can reach 58-62 HRC (Rockwell C), providing excellent edge stability and wear resistance for sharp, long-lasting blades.

Composition: High carbon (0.95-1.20%) for hardness, plus chromium (16-18%) for corrosion resistance.

Corrosion Resistance: Good in normal environments but less than 440A/B; optimum resistance achieved with proper heat treatment (avoiding overheating).

Toughness: Offers a good balance of hardness and toughness, allowing for functional blades.

Machinability: More difficult to machine than softer steels but grinds and polishes well; requires careful heat treatment to avoid softening.

Cutlery Applications

Ideal For: High-performance kitchen knives, pocket knives, tactical knives, and industrial blades.

Benefits: Holds a sharp edge well, resists abrasion, and is generally easy to sharpen and maintain.

Heat Treatment (General Guide)

Preheat: To ~1200°F (650°C) to prevent thermal shock.

Austenitize (Harden): Heat to 1700-1950°F (925-1065°C), ideally around 1900°F (1038°C).

Quench: In warm oil or air.

Temper: Below 800°F (427°C) for best corrosion resistance; tempering above this can reduce hardness and corrosion properties.

Comparison to Other Steels

vs. 420: 440C is significantly harder and stronger but more expensive and less tough than 420 stainless.

vs. 440A/B: 440C offers the highest hardness, while 440A/B provide slightly better corrosion resistance and slightly lower hardness.