Stainless Steel 420

Stainless Steel 420 is a heat-treatable martensitic stainless steel offering high hardness, strength, and good wear resistance. Its mechanical properties can be adjusted through hardening and tempering. Compared with austenitic grades such as 304 and 316, 420 is better suited for precision components requiring wear resistance, cutting edges, or higher hardness.

Appearance & Properties

Color: Silver-gray to bright silver

Density: Approx. 7.7 g/cm³

Tensile Strength: Approx. 650–1,000+ MPa (depending on heat treatment)

Corrosion Resistance: Moderate

Machinability: Moderate

Wear Resistance: Good

Weldability: Poor

Magnetism: Magnetic

Heat Treatment: Can be hardened and tempered for increased hardness and strength

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

Typical Applications

Stainless Steel 420 is widely used in medical instruments, machinery, automotive components, tooling, pumps and valves, and precision industrial parts.

Typical parts include cutting tools and blades, surgical instruments, valve components, pump shafts, gears, bushings, tooling components, precision shafts, and wear-resistant CNC parts.

Advantages

• High hardness achievable through heat treatment

• Good strength and wear resistance

• Capable of achieving a high-quality polished surface

• Suitable for wear-resistant and high-hardness precision parts

• Generally more cost-effective than some high-performance stainless steels

Limitations

• Lower corrosion resistance than 304 and 316

• Poor weldability

• CNC machining becomes more difficult after hardening

• Not suitable for highly corrosive or high-chloride environments