1.4122/AISI 440-B

Quick Facts

EN 1.4112 / AISI 440B (UNS S44003) is a high carbon martensitic stainless steel with high hardness, wear resistance and good edge retention, due to higher carbon content at the expense of corrosion resistance. Widely used in applications where high hardness and resistance are required together with good corrosion resistance.

Typical Applications

  • Automotive (eg. toolings, workpiece support and clamping devices)
  • Cutlery and knives
  • Food industries (eg. splitting blades, shaped knives and parts for meat grinders)
  • Mold inserts and active elements in plastic processing industry, even in chemically aggressive molding compounds
  • Surgical cutting tools

Industry Specifications

  • AISI 440 B / SAE 440B / AFNOR X89CrMoV18-1 / SUS440B / UNS S44003
  • ASTM A276
  • German Material no.: 1.4112
  • X90CrMoV18

Material may also be supplied against customer specifications, subject to enquiry.

Chemical Analysis

Chemical Composition, %

1.4122/AISI 440-B


AISI 440B has moderate corrosion resistance, which can be achieved in hardened and tempered conditions. The corrosion resistant is suitable in mild domestic and industrial environments such as fresh water, atmosphere, foods, mild acids and alkalis. In annealed condition, it can be machined well like high-speed steel due to the high carbon content, but after being heat treated, machining become extremely difficult in the hardened condition. AISI 440C is not usually welded because it can easily air hardened due to its high hardness characteristic.

Weldability: very poor
Machinability: 4 (1 = poor – 10 = good)
Polishability: yes
Corrosion class: 2 (0 = poor – 5 = good)

Stock Range

We supply a range of flat bars and round bars, on both stock and indent basis.
Primarily manufactured in: Europe, US