303S31 / 1.4305 - ACTON BRIGHT STEEL TECHNICAL GUIDE
303S31 / 1.4305 is a popular free cutting stainless steel and is the most machinable of all the austenitic grades. This is due to the presence of sulphur and manganese which, when combined to form manganese sulphide inclusions, results in improved & consistent machinability, good tool life and surface finish. This does however, have the effect of decreasing the corrosion resistance and a slight lowering of toughness. 303S31 / 1.4305 is typically used for nuts & bolts, gears, bushes, spindles & shafts.