Square & Rectangular Pipes (Hollow Sections)
Giriraj Impex stocks, supplies and exports square and rectangular pipes – hollow sections – in stainless steel to ASTM A554 in 304 and 316 grades, and in mild steel to IS 4923 and ASTM A500. We supply square and rectangular pipes from approved mills in standard sizes and wall thicknesses, polished, brushed or mill finish for stainless and black, galvanised or painted for mild steel, with mill test certificates.
Each square pipe and rectangular pipe is described by its outside dimensions and wall thickness. Square and rectangular pipes are used for frames, railings, gates, furniture, machine guards, architectural structures, vehicle bodies and general fabrication, where their flat faces make cutting, joining and fixing easy.
Specifications
| Item | Details |
|---|---|
| Stainless steel | ASTM A554 (welded mechanical tubing) – 304, 304L, 316, 316L; 202 on request |
| Mild steel | IS 4923 (hollow steel sections, YSt 210, 240, 310); ASTM A500 Grade B and C; EN 10219 |
| Construction | Welded, formed from strip and shaped |
| Sizes | Standard square and rectangular sizes; others on enquiry |
| Finish | Stainless: mill, 180–600 grit polished, hairline, mirror. Mild steel: black, galvanised, painted |
| Length | Standard lengths, typically 6 m, or cut to length |
| Documents | Mill test certificate (MTC); third-party inspection on request |
Size and weight chart
| Size (B × H × t), mm | Mild steel (7.85 g/cm³) | Stainless steel (7.93 g/cm³) |
|---|---|---|
| 20 × 20 × 1.5 | 0.87 | 0.88 |
| 25 × 25 × 2.0 | 1.44 | 1.46 |
| 40 × 40 × 2.0 | 2.39 | 2.41 |
| 50 × 50 × 3.0 | 4.43 | 4.47 |
| 75 × 75 × 3.0 | 6.78 | 6.85 |
| 100 × 100 × 4.0 | 12.06 | 12.18 |
| 40 × 20 × 2.0 | 1.76 | 1.78 |
| 60 × 40 × 2.0 | 3.01 | 3.05 |
| 80 × 40 × 3.0 | 5.37 | 5.42 |
| 100 × 50 × 3.0 | 6.78 | 6.85 |
| 150 × 100 × 5.0 | 18.84 | 19.03 |
Weights are calculated as (2t(B + H) − 4t²) × density; actual sections have rounded corners and weigh slightly less. Use our weight calculator for other sizes. Size availability is confirmed at the enquiry stage.
Stainless or mild steel?
Stainless steel square and rectangular pipes to ASTM A554 are used where appearance and corrosion resistance matter – railings and balustrades, architectural frames, furniture, kitchen and food equipment, and coastal structures. 304 is standard indoors and 316 for coastal and outdoor use. Mild steel hollow sections to IS 4923 or ASTM A500 are the economical choice for structures, frames and fabrication, and are galvanised or painted for protection. ASTM A554 is a mechanical tubing standard and is not used for pressure service.
Finishes for stainless sections
Stainless sections are supplied in mill finish for hidden or industrial use, or polished – typically 180, 240, 320 or 400 grit, hairline, or mirror – for visible work. Polished sections can be supplied with protective film. For outdoor and coastal use, a smoother finish improves corrosion resistance and makes cleaning easier.
Fabrication
Square and rectangular pipes are cut by saw, mitred, drilled and welded by TIG or MIG. Stainless welds are blended and repolished to match the finish, and pickled where corrosion resistance matters. Mild steel sections are welded with standard consumables and then painted or galvanised; for galvanising, vent holes are needed so molten zinc and air can flow.
Structural hollow sections
For load-bearing structures, mild steel square and rectangular hollow sections to IS 4923, ASTM A500 or EN 10219 are designed using their section properties – area, moment of inertia and section modulus – published in the standards and steel tables. Square sections are efficient as columns because they have the same stiffness in both directions, while rectangular sections are used as beams and rafters, oriented with the deeper side vertical. Galvanised hollow sections are widely used for sheds, greenhouses, solar panel structures and fencing.
Stainless sections in architecture
Stainless square and rectangular tubes give a clean, modern look in handrails, balustrades, canopies, shopfronts and furniture. For these uses, a consistent polished finish, straightness and sharp corners matter as much as strength. Grade 316 with a smooth polish of 320 grit or finer is recommended outdoors near the coast, with regular washing to prevent tea staining.
Ordering and related products
Please give the material and grade, outside dimensions and wall thickness, finish, length, quantity and any testing requirement. Related products: stainless steel welded pipes, carbon steel ERW pipes and MS pipes. All welded products are on the welded pipes and tubes page.
Frequently Asked Questions
ASTM A554 covers welded stainless steel mechanical tubing, including square and rectangular sections.
IS 4923 covers hollow steel sections for structural use.
Approximately (2t(B + H) − 4t²) × density, ignoring corner radius.
No. ASTM A554 tubing is mechanical tubing and is not intended for pressure service.
Stainless sections in mill, polished (180–600 grit), hairline or mirror finish; mild steel black, galvanised or painted.
316 stainless steel is recommended for coastal and outdoor railings.
Request a Quote for Square & Rectangular Pipes (Hollow Sections)
Tell us the product, grade, size, standard, quantity and delivery location, and our sales team will reply with a quotation.