Type 303 Stainless Steel Round is a “18-8” chromium-nickel stainless steel modified by the addition of selenium or sulfur, as well as phosphorus, to improve machinability and non-seizing properties. It is the most readily machinable of all the chromium-nickel grades and has good corrosion resistance. It is non-magnetic in the annealed condition and cannot harden by heat treatment. It is manufactured by the electric-furnace process and meets the exacting requirements of the aircraft industry.
SPECIFICATIONS AMS 5640, ASTM A 314, ASTM A 320, ASTM A 582.
APPLICATIONS Used almost exclusively for parts requiring machining, grinding, or polishing where good corrosion resistance is also required, Its non-seizing and non-galling properties make it ideal for moving parts. Being austenitic steel, it is useful where low magnetic permeability is desired.
MACHINABILITY Type 303 has considerably better machining characteristics than the other chromium-nickel grades. It has machinability rating of approximately 78% with 1212 rated 100%. Surface cutting speed on automatic screw machines is approximately 130 feet per minute.
WELDABILITY This grade has only fair welding properties.