Grade SUS440C Stainless Steel

Description

Grade SUS440C is the highest carbon variant in the SUS440 series, with a carbon content of 0.95-1.20%, making it the hardest and most wear-resistant grade among the three SUS440 sub-types. It contains 16.0-18.0% chromium and 0.75-1.25% molybdenum, providing good corrosion resistance in mild environments and enhanced pitting resistance compared to SUS440A and SUS440B. As a martensitic stainless steel, SUS440C is magnetic and requires heat treatment (quenching and tempering) to achieve its full mechanical potential, including extreme hardness (up to 60 HRC) and superior wear resistance. While it offers the best wear performance in the SUS440 series, it has limited formability and weldability due to its high carbon content, and is typically machined in the annealed state. SUS440C is ideal for high-performance applications where wear resistance is the primary requirement, even if processability is secondary.

Chemical Composition (wt%)

C: 0.95-1.20, Cr: 16.00-18.00, Mn ≤ 1.00, Si ≤ 1.00, P ≤ 0.045, S ≤ 0.030, Mo: 0.75-1.25, Ni ≤ 0.75

Mechanical Properties

Tensile Strength ≥ 960 MPa, Yield Strength ≥ 700 MPa, Elongation ≥ 6%, Hardness ≤ 302 HB (annealed); Tensile Strength ≥ 1380 MPa, Yield Strength ≥ 1100 MPa, Elongation ≥ 5%, Hardness 58-62 HRC (heat-treated)

Advantages

Exceptional hardness and wear resistance (highest in the SUS440 series); good corrosion resistance in mild environments; enhanced pitting resistance due to molybdenum; magnetic; heat-treatable to extreme hardness; ideal for high-wear applications.

Applications

High-precision bearings, cutting tools, surgical instruments, industrial blades, valves, gears, and high-performance components requiring superior wear resistance.

Equivalent Grades

AISI 440C, UNS S44004, EN 1.4122, GB 9Cr18

 

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.