Stainless Steel 303

Stainless Steel 303 is a free machining non-magnetic austenitic alloy specially designed for improved machinability while maintaining good mechanical and corrosion resistant properties. AISI 303 is cannot be hardened by heat treatment, but tensile and hardness can be increased by cold working with subsequent reduction in ductility.The sulfur addition which is responsible for the improved machining and galling characteristics of Grade 303 lowers its corrosion resistance to below that of Grade 304. However, fairly resistant to general atmospheric corrosion, general foodstuffs, sterilizing solutions, dyestuffs, most organic chemicals, but has very limited resistance to acids.

Chemical Properties:

Mechanical Properties:

Physical Properties:

Equivalent Grades and Designations:

Heat Resistance:

• Good oxidation resistance at temperatures up to 1700oF (927 oC)
• Continuous use at temperatures above 1400oF (760oC) is not usually recommended due to carbide precipitation which can lead to irregular scaling
• Does not have a low carbon content so it is also vulnerable to sensitization

Welding Characteristics:

• Not generally recommended, but may be welded with some difficulty
• May be welded with Alloy 310 electrodes
• Should be annealed after welding to re-dissolve precipitated carbides

Machinability:

• High machining rates can be obtained in the annealed condition with hardness in the range of 200 to 240 Brinell
• Will work harden; therefore, it should be machined at reduced surface feet per minute and heavier feeds to prevent glazing at the tool interface.

Applications:

• Nuts and bolts
• Aircraft fittings
• Gears
• Screws
• Shafts
• Electrical switchgear components
• Bushings