310 Stainless Fasteners
As in-service temperature levels have been raised over time, the importance of 310 has increased. Chromium content contributes to heat resistance. However, straight chromium grade stainless steels (400 series) are only effective up to 1250º F (700º C). Austenitic grades, particularly 347 Stainless and 316 Stainless are used in environments up to 1600º F (850º C). 310 Stainless fasteners are used where temperatures may reach 2000º F (1100º C). A .25% maximum carbon content is permissible in 310 Stainless. When carbon content is held under .08%, the material qualifies as 310S Stainless. In practice, most heat lots of 310 qualify as 310S. 309 Stainless (UNS S30908) is used in similar environments. However, it is generally less available. Navaratna stocks 310 Stainless socket head cap screws, particularly in 1/4" and 3/8" diameters. We are also accumulating inventory in 310 Stainless heavy hex bolts. Finished hex head bolts and hex nuts, both finished and heavy patterns, in 310 Stainless can generally be supplied within a short lead-time.
ASTM A240 (Plate)
ASTM A479 (Bar)
Typical Tensile Strength (at room temperature in KSI)
Typical Chemistry (% by weight)
C .02, Cr 25, Fe 52, Mn 1.5, Ni 20, P .3, S .2