IS 196 covers weathering steel (Corten equivalent) that forms a protective rust patina, eliminating the need for painting. Used for bridges, transmission towers, and architectural features where maintenance-free steel is desired.
Specification for atmospheric corrosion resistant (weathering) steel plates, bars, and sections for structural use where painting is not required.
Key Values
Yield strengthMin 340 MPa
Tensile strength480-620 MPa
Copper content0.25-0.55%
Practical Notes
! Weathering steel must NOT be painted — the protective patina needs atmospheric exposure to form.
! Not suitable for coastal environments (>2km from sea) or industrial areas with high SO2 levels.
! Initial rusting looks like corrosion — takes 2-3 years for the stable patina to form fully.
! Keep weathering steel away from water pooling — constant wet surfaces prevent patina formation.