Stainless Steel 303 - Alloy Composition

Stainless steel type 303 is part of a family of stainless steel alloys (301, 302, 303, 304, 316, 347). 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 machinable austenitic stainless steel; however, the sulfur addition does lower Alloy 303’s corrosion resistance to below that of Alloy 304. Like other austenitic grades, 303 shows excellent toughness, the lower sulfur content does reduce this slightly

 Nominal Composition in Percent:

            Ni                     9.00

            Cr                    18.00

            Fe                  Balance

            Si                    1.00

            Mn                   2.00

            C                     0.120

            P                     0.040

            S                     0.030

UNS Number:

S30300

Other Standard Specifications:

300 Series—austenitic chromium-nickel alloys

Density:

8.03 g/cm3 (0.290 lbs/in2)

 

Exceptional Properties:

Toughness, durability, corrosion resistance