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.