Alloy 303 grade stainless steel (UNS S30300) can is used as plate, round bar, square bar, hex bar, and rolled flat bar. Alloy 303 is a non-magnetic, austenitic stainless steel that is not hardenable by heat treatment. It is the free machining modification of the basic 18% chromium / 8% nickel stainless steel. Alloy 303 was specially designed to exhibit improved machinability while maintaining good mechanical and corrosion resistant properties due to the presence of sulfur in the steel composition; Alloy 303 is the most readily machineable austenitic stainless steel. It is however, fairly resistant to general atmospheric corrosion, general foodstuffs, sterilizing solutions, dyestuffs, most organic chemicals, plus some inorganic chemicals. Like other austenitic grades, Alloy 303 demonstrates excellent toughness, although the sulfur does reduce this a little as well. Alloy 303 was developed as a free machining grade, and has by far the best machinability of all the 300 series austenitic stainless steels, and indeed has better machinability than most of the 400 series martensitic stainless steels with the exception of the free machining grades. Alloy 303 is not generally recommended for welding due to its high sulfur content which can cause hot cracking. However if unavoidable, the following procedures may be taken as a guide. Alloy 303 is nonmagnetic in the annealed condition, but can become mildly magnetic following heavy cold working. Annealing is required to rectify if necessary.
Applications and typical uses of alloy 303 are: Architectural Components, Food Processing Equipment, Dairy Equipment, Dying Industry, Hardware and Kitchenware manufacturing and allied industries. Commonly used to manufacture Bolts and Nuts, Bushes, Gears, Shafts, Valve Bodies and Fittings, Aircraft fittings, Gears, Screws, Electrical switchgear components, Bushings, Automatic screw machines, Conveyor systems