IS 6603 covers stainless steel bars and flats in austenitic (304, 316), martensitic (410, 420), and ferritic grades. 304 and 316 are the most commonly used grades in India for corrosion-resistant applications in food, chemical, pharmaceutical, and marine industries.
Specification for stainless steel bars and flats (round, square, hexagonal, flat) covering grades, dimensions, mechanical properties, and testing.
Key Values
304 (04Cr18Ni10) yieldMin 205 MPa
304 tensileMin 520 MPa
316 (04Cr18Ni10Mo2) yieldMin 205 MPa
Practical Notes
! 304 is the standard grade for general corrosion resistance. 316 for marine/chemical (has molybdenum).
! Always specify the exact grade — '304' and '316' have very different prices and corrosion resistance.
! Intergranular corrosion (IGC) test is critical for welded austenitic SS — sensitization during welding can cause failure.
! Indian SS designation system differs from AISI: IS 04Cr18Ni10 = AISI 304 = EN 1.4301.