IS 2779:1991 is the Indian Standard (BIS) for galvanized steel sheets (plain and corrugated). This standard (commonly known as IS 277; the number IS 2779 is a likely typo) specifies the requirements for plain and corrugated galvanized steel sheets. It covers various material grades, zinc coating mass classes, dimensions, tolerances, and testing procedures for sheets primarily used in roofing, cladding, and paneling.
Specifies requirements for hot-dip galvanized plain and corrugated steel sheets.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Standard Coating Mass | Class 275 (min. 275 g/m² total) | Z275 (min. 275 g/m² total) | EN 10346:2015 / ISO 3575:2016 |
| Heavy Coating Mass | Class 600 (min. 600 g/m² total) | Z600 (min. 600 g/m² total) | EN 10346:2015 |
| Base Steel Grade (Forming) | Deep Drawing (DD) Grade | DX54D+Z (for extra deep drawing) | EN 10346:2015 |
| Bend Test (Forming Grade) | 180° close bend (0t mandrel) for DD grade | 180° bend, flat on itself (0t mandrel) for DX53D and higher | EN 10346:2015 |
| Sulphur Content (max, for Deep Drawing) | 0.035% | 0.025% (for DX54D) | EN 10346:2015 |
| Thickness Tolerance (for 1.0mm sheet, <1250mm wide) | ±0.08 mm | ±0.06 mm (normal tolerance) | EN 10346 (via EN 10051) |
| Coating Adhesion Test | Lock forming test specified, no peeling or flaking of coating. | Mandatory bend test (T-bend test) with specific criteria for coating adhesion. | ASTM A653 / A653M - 23 |