instrument and implant grade metal alloys

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Stainless Steel 431 (1.4057) Medical Alloy

Stainless Steel 431 (1.4057) is an ESR martensitic stainless steel, with enhanced corrosion resistance due to its high Chromium and Nickel contents, and low Carbon and Sulphur contents. It is best used in the quenched, tempered condition with polished and passivated surface. 431 has the best corrosion resistance of all the martensitic grades and its excellent mechanical properties make it ideal for use in numerous applications and especially medical, surgical and dental instruments.

As well as meeting the requirements of ASTM F899 for medical instruments, 431 can also be supplied in the hardened and tempered condition and certified to the aerospace specification BS S80D.

Typical Chemical Composition

C Si Mn P S Cr Mo Ni V Nb N Fe
Min 0.12 15.00 1.50
Max 0.22 1.00 1.50 0.04 0.015 17.00 2.00 Balance

Typical Mechanical Properties

Condition Tensile (Rm)
Yield (R0.2%)
A4d (%)
Softened ≤ 277
Hardened & Temp 880-1080 ≥ 690 12 270-340


JIS 431
UNS 43100
AMS 5628
BS S80


Stainless Steel 431 (1.4057) is readily available in precision ground bar and wire starting from 2.00mm diameter

Disclaimer : Every effort is made to ensure that technical specifications are accurate. However, technical specifications included herein should be used as a guideline only. All specifications are subject to change without notice.

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NOTE: Weights calculated are theoretical. Manufacturing tolerances should be allowed for and results adjusted accordingly.