SUS440A – Low-Carbon 440-Series Martensitic Alloy For Balanced Performance

Overview

SUS440A is the low-carbon variant of the JIS 440-series martensitic stainless steels, offering a balanced combination of wear resistance, corrosion resistance, and toughness. With 0.60-0.75% carbon and 16.00-18.00% chromium, it is easier to heat treat than higher-carbon 440 variants (SUS440B/SUS440C), while still providing excellent wear resistance and edge retention. It contains a small addition of molybdenum to enhance corrosion resistance, making it suitable for applications requiring a balance of performance and processability. It is magnetic, has good machinability when annealed, and achieves a hardness of 54-56 HRC after heat treatment.

Chemical Composition (wt%)

C: 0.60-0.75, 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): ≥ 1800 MPa; Yield Strength (Rp0.2): ≥ 1650 MPa; Elongation (A): ≥ 5%; Hardness (HRC): 54-56

Core Advantages

Balanced wear resistance and toughness; best corrosion resistance among 440-series variants; easier to heat treat than SUS440B/SUS440C; magnetic; good machinability in the annealed state; excellent edge retention for cutting tools; cost-effective for medium-wear applications.

Applications

Kitchen knives, scissors, surgical scissors, bearings, valve components, industrial cutting blades, and precision components requiring a balance of wear resistance, corrosion resistance, and toughness.

Equivalent Grades

EN 1.4125, UNS S44002, GB 9Cr18Mo, AISI 440A

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.