1.4125/ AISI 440C

Quick Facts

EN 1.4125 / AISI 440C (UNS S44004) 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. Good corrosion resistance can be achieved in hardened and tempered condition. Widely used in applications where high hardness and resistance are required together with good corrosion resistance.

Typical Applications

  • Ball bearings and races
  • Cutlery and knives
  • Food industries (eg. splitting blades, shaped knives and parts for meat grinders)
  • Measuring Instrument
  • Surgical Instrument
  • Valve and pump components

Industry Specifications

  • AISI 440C / UNS S44004 / JIS SUS440C / GB 108Cr17 / GOST 95Ch18 /AFNOR Z100CD17
  • AMS 5630
  • ASTM A 276 / A 484
  • German Material no.: 1.4125
  • X105CrMo17

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

Chemical Analysis

Chemical Composition, %

1.4125/ AISI 440C


AISI 440 C 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 too 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