304 Stainless steel is a low carbon (0.08% max) version of basic 18-8.this grade also known as 302. Type 304 has slightly lower strength than 302 because of its lower carbon content.grade 302 contain 18% chromium and 8% nickel. ASTM A269 TP 304 Stainless Steel Seamless Tubes widely use in welding applications because without the need for post-annealing operations the low carbon allow some exposure in the carbide precipitation range of 800°F - 1500°F.