STS440C – High-Carbon 440-Series Martensitic Alloy For Maximum Wear Durability

Overview

STS440C is the high-carbon variant of the STS 440-series, delivering maximum wear resistance and hardness among 440-series grades. With 0.95-1.20% carbon and 16.00-18.00% chromium, it achieves a hardness of 58-60 HRC after heat treatment, making it ideal for applications requiring extreme wear resistance and edge retention. It contains molybdenum to enhance corrosion resistance and hardenability, and is magnetic with good machinability when annealed. Compared to STS440A and STS440B, it is more prone to brittleness and requires careful heat treatment (including deep cooling below -70°C), but offers unmatched wear durability for critical applications.

Chemical Composition (wt%)

C: 0.95-1.20, Cr: 16.00-18.00, Mo: 0.75-1.25, Mn ≤ 1.00, Si ≤ 1.00, P ≤ 0.040, S ≤ 0.030, Ni ≤ 0.75

Typical Mechanical Properties (Quenched & Tempered Condition)

Tensile Strength (Rm): ≥ 1970 MPa; Yield Strength (Rp0.2): ≥ 1900 MPa; Elongation (A): ≥ 2%; Hardness (HRC): 58-60

Core Advantages

Maximum wear resistance and hardness among 440-series variants; excellent edge retention for high-performance cutting tools; moderate corrosion resistance; magnetic; good machinability in the annealed state; high-temperature dimensional stability; suitable for extreme wear-intensive applications; highest tensile strength in the 440 series.

Applications

High-performance tactical knives, precision bearings, surgical blades, molds, valve components, pump shafts, and critical wear parts requiring extreme durability and edge retention.

Equivalent Grades

EN 1.4125, UNS S44004, GB 11Cr17, AISI 440C, SUS440C

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.