Steel Tubes for Closed Hollow Structures
Steel Tubes for Closed Hollow Sections (IS:4923)
IS:4923 specifies requirements for cold-formed welded hollow steel sections intended for structural use. These sections are manufactured from hot-rolled steel coils by the Electric Resistance Welding (ERW) process and are available in Square (SHS), Rectangular (RHS), and Circular (CHS) profiles across three primary grades: YSt 210, YSt 240, and YSt 310.
Key Specifications
| Standard | IS:4923 — Hollow Steel Sections for Structural Use |
| Manufacturing Process | Cold-formed ERW (Electric Resistance Welded) |
| Grades Available | YSt 210 / YSt 240 / YSt 310 |
| Sections Available | Square (SHS) / Rectangular (RHS) / Circular (CHS) |
| Size Range — SHS | 20 mm × 20 mm to 400 mm × 400 mm |
| Size Range — RHS | 40 mm × 20 mm to 450 mm × 250 mm |
| Wall Thickness | 0.5 mm to 25 mm |
| Standard Length | 6.0 m ± 50 mm (custom lengths 3 m to 18 m available) |
| Surface Finish | Plain (mill finish) / Galvanized (as per IS:4736) |
| Testing | Flattening test, Bend test, Hydraulic test |
Grades & Mechanical Properties
| YSt 210 | Yield Strength: 210 MPa min / Tensile Strength: 330 MPa min / Elongation: 20% min |
| YSt 240 | Yield Strength: 240 MPa min / Tensile Strength: 410 MPa min / Elongation: 15% min |
| YSt 310 | Yield Strength: 310 MPa min / Tensile Strength: 450 MPa min / Elongation: 10% min |
Typical Applications
- Structural frames, trusses, and columns in buildings and industrial sheds
- Architectural facades, canopies, and support frameworks
- Gates, railings, grills, and fencing
- Conveyors, mezzanine floors, and material handling structures
- Sign boards, hoardings, and lighting pole structures
- Bridges, towers, and heavy infrastructure fabrication
- Furniture frames and modular interior structures
Supply
Available in standard lengths of 6 metres with plain square-cut ends. Custom lengths from 3 metres to 18 metres can be supplied on request. All sections conform to IS:4923 and are supplied with mill test certificates. Special grades YSt 355, YSt 420, and YSt 460 available on request for high-strength structural requirements.