IS 4923 Hollow Sections (SHS/RHS)
Structural Carbon Steel Hollow Sections for High-Strength Engineering
IS 4923 is the definitive Indian standard for hollow steel sections used in structural applications. These sections, including Square Hollow Sections (SHS) and Rectangular Hollow Sections (RHS), offer a superior strength-to-weight ratio compared to conventional steel channels or angles. Available in yield strength grades YST 210, YST 240, and YST 310, they provide excellent torsional rigidity and aesthetic appeal, making them indispensable for airport terminals, metro stations, industrial sheds, and furniture frames.
Technical Specifications
| Feature | Details |
|---|---|
| Standard | IS 4923 : 1997 (Structural Steel) |
| Grades | YST 210, YST 240, YST 310 |
| Profiles | Square (SHS) and Rectangular (RHS) |
| Size Range | SHS: 25x25mm to 300x300mm | RHS: 50x25mm to 400x200mm |
| Thickness | 2.0 mm to 16.0 mm |
| Manufacturing | Hot Rolled or Cold Formed ERW |
Mechanical Properties
| Grade | Yield Strength (Min) | Tensile Strength (Min) | Elongation (Min %) |
|---|---|---|---|
| YST 210 | 210 MPa | 310 MPa | 12% - 25% |
| YST 240 | 240 MPa | 410 MPa | 10% - 15% |
| YST 310 | 310 MPa | 450 MPa | 8% - 10% |
Chemical Composition (%)
| Element | Percentage (Max) |
|---|---|
| Carbon (C) | 0.20% max (for YST 210/240) / 0.25% (YST 310) |
| Manganese (Mn) | 1.30% max |
| Phosphorus (P) | 0.040% max |
| Sulphur (S) | 0.040% max |
Features and Benefits of IS 4923 Hollow Sections
- Superior torsional rigidity compared to open structural sections
- High strength-to-weight ratio leading to significant material savings
- Flat surfaces simplify joining, welding, and structural bolt connections
- Uniformity in wall thickness ensured through precise ERW manufacturing
- Excellent surface finish suitable for high-quality painting and powder coating
- Reduced surface area minimizes painting costs and corrosion exposure
- Versatile sub-grades (YST 210-310) to match specific load requirements
Applications & Uses
Architecture
Used in airport roofing, stadium space frames, and modern glass facades.
Industrial
Applied in conveyor systems, material handling equipment, and storage racks.
Automotive
Primary choice for bus body building, truck trailers, and heavy machinery chassis.