1.4034/AISI 420

Quick Facts

EN 1.4034 / AISI 420 (UNS S42000) is a high carbon martensitic stainless steel, it can be hardened through heat treatment to achieve hardness greater than that of grade 1.4031, due to the higher carbon content. Corrosion resistance can also be optimized by polishing the material surfaces in hardened condition. Grade 1.4034 is often used in application in moderately aggressive media which requires high hardness.

Typical Applications

  • Food industry (eg. Cutlery, knives, blades)
  • Needle valves
  • Medical and pharmaceutical industry
  • Surgical and dental instruments

Industry Specifications

  • AISI 420 / AFNOR Z44C14 / Z38C13M / BS420S45 / 4H13AMS 5630
  • ASTM A 276 / A 484
  • German Material no.: 1.4034
  • X105CrMo17

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

Chemical Analysis

Chemical Composition, %

1.4034/AISI 420


The corrosion resistance level of AISI 420 is suitable in mild domestic and industrial environments such as fresh water, atmosphere, foods, mild acids and alkalis, which can be achieved in hardened and tempered conditions and polished surface. 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: 5 (1 = poor – 10 = good)
Polishability: yes
Corrosion class: 1 (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