Stainless Steel 303 is a non-magnetic austenitic steel type. Alloy 303 Pipes cannot be hardened through heat treatment. It is a basic 18-8 chromium-nickel steel type with free machining. Grade 303 pipes are well-known for its retention of good mechanical abilities with machinability and good corrosion resistance properties. But 303 has lower carbon content, which results in its susceptibility towards sensitization.
Alloy steel 303 is readily machine able due to the presence of sulphur in its composition. Unlike 304 the corrosion resistance of 303 Pipes is lowered due to the presence of added sulphur. Grade 303 is also known for its demonstration of toughness. Sulphur addition also results in poor weldability and formability for the grade. Mildly corrosive environments are not a problem for Grade 303 seamless pipes, but the resistance is significantly lesser when compared to 304. Resistance to marine corrosion is minimal in 303 hence, it is advised to not be used in Marine applicatio