310 stainless steel bar, also known as UNS S31000 and Grade 310, contains the following primary elements: .25% maximum carbon, 2% maximum manganese, 1.5% maximum silicon, 24% to 26% chromium, 19% to 22% nickel, traces of sulfur and phosphorus, with the balance being iron. Type 310 is superior in most environments to 304 or 309 due to its relatively high chromium and nickel content. It exhibits a combination of good strength and corrosion resistance in temperatures up to 2100° F. Cold working will cause 309 to increase in hardness and strength, and it does not respond to heat treatment.
