Grade 420 stainless steel is a high-carbon martensitic stainless steel designed to deliver exceptional hardness, high strength, and moderate corrosion resistance. Often referred to as “surgical steel,” this alloy can be heat-treated to achieve a rockwell hardness of up to 50 HRC, making it the premier choice for cutting edges, wear surfaces, and high-stress mechanical parts.
💡 Key Characteristics & Properties
- High Wear Resistance: Thanks to its high carbon content, Grade 420 can be hardened through quenching and tempering to resist severe abrasive wear.
- Moderate Corrosion Resistance: It offers good resistance to fresh water, mild acids, alkalis, air, and food acids, but only when it is fully hardened and polished.
- Magnetic Nature: Unlike austenitic grades (like 304 or 316), Grade 420 is highly magnetic in all conditions.
- Limited Weldability: Due to its hardening characteristics, welding Grade 420 is difficult and requires extensive pre-heating and post-weld annealing to prevent cracking
🛠️ Common Applications
Grade 420 is widely used in industries requiring sharp edges, high tensile strength, and hygienic properties:
- Cutlery and Blades: Chef knives, hunting knives, and industrial shear blades that must hold a sharp edge.
- Medical Instruments: Surgical tools, dental instruments, and forceps due to their hardness and ability to withstand repeated sterilization.
- Mechanical Components: Valve parts, pump shafts, needle valves, pistons, and ball bearings subjected to continuous friction.
- Plastic Moulds: Injection moulds that require high polishability and resistance to abrasive plastics.
Our External and Internal Circlips are available in 420 Stainless, and available to order online.
