IS 1079 specifies hot rolled carbon steel sheets, strips, and coils for commercial, drawing, and structural use. Four grades (HR1 to HR4) cover applications from general fabrication to deep drawing. This is the base material specification for HR steel traded in India.
Specification for hot rolled carbon steel sheet, strip, and coil for structural, commercial, and forming applications.
Key Values
HR1 yield strengthMax 310 MPa
HR2 yield strengthMax 280 MPa
HR3 yield strengthMax 260 MPa
Practical Notes
! HR steel is significantly cheaper than CR (IS 513) — use HR where surface finish is not critical.
! Mill scale must be removed before painting or galvanizing — specify pickling if clean surface needed.
! HR1 is the most commonly stocked grade. For structural use, prefer IS 2062 which has guaranteed mechanical properties.
! Thickness tolerance on HR coils is wider than CR — check Table 3 before designing close-tolerance parts.