STS420 – Medium-Carbon Martensitic Alloy For Balanced Hardness & Practical Corrosion Protection

Overview

STS420 is a medium-carbon martensitic stainless steel, offering a well-balanced combination of hardness, wear resistance, and corrosion protection. With 12.00-14.00% chromium and 0.16-0.25% carbon, it can be heat-treated (quenched and tempered) to achieve a hardness of 50-53 HRC, making it suitable for cutting tools and precision components. It is magnetic, has good machinability in the annealed state, and exhibits reliable performance in atmospheric and mild chemical environments. Unlike high-carbon martensitic grades, STS420 prioritizes toughness, making it less prone to brittleness during fabrication.

Chemical Composition (wt%)

C: 0.16-0.25, Cr: 12.00-14.00, Mn ≤ 1.00, Si ≤ 1.00, P ≤ 0.040, S ≤ 0.030, Ni ≤ 0.75

Typical Mechanical Properties (Quenched & Tempered Condition)

Tensile Strength (Rm): ≥ 850 MPa; Yield Strength (Rp0.2): ≥ 550 MPa; Elongation (A): ≥ 10%; Hardness (HRC): 50-53

Core Advantages

Heat-treatable to achieve balanced hardness and toughness; good corrosion resistance in mild environments; excellent machinability in the annealed state; magnetic; easy to polish for functional or decorative parts; cost-effective alternative to high-carbon grades; predictable heat treatment response.

Applications

Kitchen knives, scissors, surgical instruments, valve components, pump shafts, plastic molds, and general hardware requiring moderate strength, wear resistance, and corrosion protection.

Equivalent Grades

EN 1.4021, UNS S42000, GB 20Cr13, AISI 420, SUS420J1

Stainless Steel Suppliers

If you have project requirements for stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com

 

Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
Packaging: Wooden crate packaging, bubble wrap packaging, steel strapping, or packaging according to customer requirements.