Square Steel Hollow Section (SHS): IS 4923 Manufacturer in India
If you're sourcing a square tube, square pipe, MS square pipe, or square hollow section for a structural, architectural, or fabrication project, this page covers everything you need to specify one correctly: size range, thickness options, applicable IS code, grade, tolerances, and where this shape fits best on a project. SRMB Realfabrica manufactures square hollow sections at SRMB Srijan's integrated steel plant in Durgapur, West Bengal, rolling our own hot rolled coil into finished square sections on Cold Formed ERW lines, under IS 4923.
What Is a Square Hollow Section?
A square hollow section (SHS) is a structural steel tube with a square cross section and a hollow core, used as a load bearing member in construction, architecture, and general fabrication. You'll see it referred to by several names depending on the industry and the person asking: square tube, square pipe, MS square pipe, MS square tube, SHS pipe, square hollow steel, or MS box section. All of these terms describe the same family of product that SRMB Realfabrica manufactures under IS 4923.
Because all four sides of an SHS are equal, the section resists bending and compressive load the same way regardless of which direction the force comes from. That symmetry is what makes it a straightforward choice wherever a structural member needs to carry axial or evenly distributed load, most commonly as a column, but also across framing, furniture, and fabrication work covered later on this page.
Full Specifications
| Specification | Detail |
|---|---|
| Product standard | IS 4923 (Hollow steel sections for structural use, square and rectangular) |
| Size range | 20mm x 20mm to 91.5mm x 91.5mm |
| Thickness range | 1.0mm to 4.8mm |
| Grade | YST 210, YST 240 (higher grades also manufactured on request) |
| Standard length | 6 metres to 7 metres, precision cut on request |
| Surface finish | Black, smooth finish |
| Input material | Hot rolled coil conforming to IS 10748 |
| Forming process | Cold Formed ERW (Electric Resistance Welded) |
Choosing the Right Size and Thickness
As a general rule, smaller sections in the 20x20mm to 40x40mm range suit lighter applications such as furniture frames, railings, and decorative structural elements, where load is modest but appearance and ease of fabrication matter most. Mid sized sections from 49.5x49.5mm to 72x72mm are commonly specified for machinery framework, signage supports, and general fabrication work. Larger sections from 80x80mm to 91.5x91.5mm are typically chosen for structural columns and beam framing in construction, where higher axial load needs to be carried safely. Thickness should always be selected based on the specific load calculation for your structure, in consultation with your structural engineer, rather than by size alone, since two sections of the same outer dimension can carry very different loads depending on wall thickness.
Grades & Mechanical Properties
| Grade | Yield Strength (YST), Minimum | Ultimate Tensile Strength (UTS), Minimum | Elongation, Minimum |
|---|---|---|---|
| YST 210 | 210 MPa | 330 MPa | 12% (up to 25.4mm), 20% (above 25.4mm) |
| YST 240 | 240 MPa | 410 MPa | 10% (up to 25.4mm), 15% (above 25.4mm) |
Dimensional Tolerances
| Parameter | Tolerance |
|---|---|
| Outside dimension | +/- 1% of nominal size, with a minimum of +/- 0.50mm |
| Thickness | +/- 10% |
| Squareness | 90 degrees +/- 2 degrees |
| Corner radius | 3t maximum (t = wall thickness) |
| Weight, individual lengths | +10% / -8% |
| Weight, 10 tonne lot | +/- 7.5% |
Where Square Hollow Sections Are Used
- Columns and beam structures in building construction
- Framework for machinery and equipment
- Furniture design and manufacturing
- Architectural and decorative structural elements
- Sign and billboard supports
- Guardrails and protective barriers in industrial settings
These uses span architectural, industrial, general engineering, and infrastructural projects, which is why we manufacture across such a wide range of sizes and thicknesses. Whatever the sector, the same square symmetry that makes SHS efficient as a column also makes it a versatile, easy to fabricate structural building block.
Why Square Hollow Sections Are Specified Over Other Shapes
Balanced structural performance
Equal sides mean equal resistance to bending and compression from any direction, making SHS a dependable choice for axially loaded members like columns.
Simplified connections
Flat, equal faces make it straightforward to design and fabricate bolted or welded connections without the orientation checks a rectangular or circular section can require.
Torsional resistance
The closed square profile offers strong resistance to twisting forces, which is valuable in framework and equipment subject to varying load directions.
Visual consistency
The uniform square profile reads cleanly from every viewing angle, which is why architects and furniture designers often prefer it for exposed structural elements.
Where a project instead calls for a stronger axis and a weaker axis, such as in long span beams, our rectangular hollow section range may be a better fit, and where a curved or rotationally symmetric profile is needed, our circular hollow section range covers that requirement.
Manufacturing Quality Behind Every Length
Every square hollow section we supply traces back through a single, integrated chain: iron ore and other raw materials are processed into hot metal, refined into steel, and rolled into hot rolled coil at SRMB Srijan's own steel making facilities, before that coil is formed into finished square hollow sections on our Cold Formed ERW lines in Durgapur, West Bengal. Because we control the input material ourselves rather than sourcing coil externally, we can hold tighter chemistry and dimensional control from the first stage of production through to the finished section.
Primary Steel Producer
We manufacture our own steel from raw material stage, giving full control over chemistry and quality rather than relying on externally sourced coil.
Batch level testing
Mechanical and dimensional properties are tested at the batch level, so every lot dispatched has verified conformance to specification.
IMS certification
Our manufacturing operations run under an Integrated Management System certification, covering quality, environmental, and safety standards.
On-product traceability
Sections carry markings that allow every length to be traced back to its production batch, supporting quality audits and project documentation.
Handling and Site Considerations
Weldability
YST 210 and YST 240 grade square hollow sections have low carbon content and are readily weldable using standard fabrication welding processes, without requiring preheating under normal site conditions.
Open ends
Sections are supplied with open ends as standard. Where corrosion protection of the internal surface is required, sealing or capping should be planned into the fabrication sequence.
Packaging
Sections are bundled and strapped for safe transit and site handling, with bundle labelling that identifies size, thickness, grade, and batch to support easy identification on receipt at site.
How to Order
Share your required size, thickness, grade, and quantity with our technical team, and we'll confirm availability, lead time, and a formal quotation for your project. For quick reference on sizes and weights, download our product brochure below.
Frequently Asked Questions
A square hollow section is a structural steel tube with a square cross section and hollow core, used as a load bearing member. It's also called square tube, square pipe, MS square pipe, or MS box section.
We manufacture square hollow sections from 20mm x 20mm to 91.5mm x 91.5mm, including standard sizes such as 25x25, 40x40, 60x60, and 80x80mm, under IS 4923.
Our square hollow sections are available in thicknesses from 1.0mm to 4.8mm. Not every size is available in every thickness, so please confirm your exact combination with our technical team.
SRMB Realfabrica square hollow sections conform to IS 4923, which covers hollow steel sections for structural use in square and rectangular profiles.
We manufacture square hollow sections in YST 210 and YST 240 as standard grades, with higher grades available on request for projects requiring greater yield strength.
Standard supply length is 6 metres to 7 metres. Precision cut lengths can be arranged on request for specific project requirements.
Square hollow sections are used for structural columns, machinery framework, furniture manufacturing, architectural elements, sign and billboard supports, and industrial guardrails.
Outside dimension tolerance is +/- 1% (minimum +/- 0.50mm), thickness tolerance is +/- 10%, and squareness is held to 90 degrees +/- 2 degrees, as per IS 4923.
Controlled chemistry and a smooth surface finish support good corrosion resistance. Sealing all open ends with a welded end plate further protects against internal corrosion over the section's working life.
Yes. SRMB Realfabrica square hollow sections can be welded using standard MS electrodes without any preheating required beforehand.
For weight per length and a detailed size chart for your required specification, please contact our technical team or download our product brochure for the latest data.
Square sections have equal sides and spread load evenly in all directions, suiting columns. Rectangular sections have unequal sides, giving more strength along one axis, suiting beams and trusses.
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