Alloy 303 (UNS S30300) is an austenitic stainless steel developed for applications requiring extensive machining operations. The alloy has a sulfur addition which assists in breaking up turnings while reducing drag on the cutting tool when compared to the machining characteristics of the conventional 18-8 stainless steels. 303 SS is a free-machining, austenitic stainless steel that is used primarily for parts requiring machining, grinding or polishing. The additional sulfur present in 303 assists in breaking up turnings which reduce drag on the cutting tool. This alloy offers good corrosion resistance in mild environments and good forming properties. It is non-magnetic in the annealed condition, is not hardenable by heat treatment, and can only be hardened by cold working. It is also difficult to weld, and may require filler rods and annealing. The improved machinability of 303 stainless (UNS S30300) makes it ideal for screw machine applications, aircraft fittings, and fasteners. The additional sulfur that allows this product to be readily machinable also lowers its corrosion resistance compared to a grade like 304. Overall toughness is lower but still good despite the inclusion of sulfur, and is comparable to other austenitic grades of stainless steel. We offer 303 stainless in plate from 0.1875” to 4.000” thicknesses.