Stainless Steel 440C

Stainless Steel 440C is a high-carbon, high-chromium martensitic stainless steel known for its high hardness, excellent wear resistance, and good dimensional stability. After proper heat treatment, it can achieve very high hardness, making it particularly suitable for bearings, cutting tools, and precision mechanical components requiring high strength and wear resistance.

Appearance & Properties

Color: Silver-gray to bright silver

Density: Approx. 7.7–7.8 g/cm³

Hardness: Typically around 58–60 HRC after heat treatment

Corrosion Resistance: Moderate to good

Machinability: Moderate when annealed; difficult after hardening

Wear Resistance: Excellent

Weldability: Poor

Magnetism: Magnetic

Surface Finishes: Polishing, grinding, bead blasting, passivation, etc.

Typical Applications

Stainless Steel 440C is widely used in bearings, precision machinery, aerospace, medical instruments, tooling, and high-wear industrial equipment.

Typical parts include bearings and balls, precision shafts, valve components, cutting tools, wear-resistant bushings, tooling components, rollers, and high-hardness precision CNC parts.

Advantages

• High hardness after heat treatment

• Excellent wear resistance

• Good strength and dimensional stability

• Capable of achieving a high-quality polished surface

• Ideal for high-hardness and wear-resistant precision components

Limitations

• Lower toughness than some lower-carbon stainless steels

• Poor weldability

• Difficult to CNC machine after hardening

• Lower corrosion resistance than austenitic grades such as 304 and 316