Product Overview
Carbon steel rectangular tube (rectangular hollow section, RHS) is a cold-formed or welded hollow profile with a rectangular cross-section. It combines a high strength-to-weight ratio, clean lines, and easy connection, making it a staple of structural frames, machinery enclosures, and architectural systems. Huaxia-Steel supplies carbon steel rectangular tubes from 20×10 mm to 400×200 mm, wall thickness 1.0 – 16 mm, in Q235B, Q345B, SS400, S355JR, A500 Grade B/C, and equivalent grades — ERW welded or seamless, with galvanized and painted finishes.
Specifications
| Parameter | Range | Standard / Tolerance |
|---|---|---|
| Outer size | 20×10 – 400×200 mm | EN 10219 / ASTM A500; corner radius per std |
| Wall thickness | 1.0 – 16 mm | ± 10% or ± 0.3 mm typical |
| Length | 4 – 12 m (random or fixed) | ± 5 mm typical |
| Straightness | ≤ 1/1000 of length | Per EN 10219 |
| Corner radius | 1.5t – 2.5t | Per forming standard |
| Mass | Per theoretical weight table | Density 7.85 g/cm³ |
Available Grades
| Standard | Grades | Typical Use |
|---|---|---|
| EN 10219 | S235JR, S355JR | European structural hollow sections |
| ASTM A500 | Grade B, Grade C | North American structural tubing |
| GB/T 6728 | Q235B, Q345B | Domestic and export general use |
| JIS G3466 | STKR400 | Japanese general structural tubing |
Manufacturing Standards
- ERW (electric resistance welded): strip is cold-formed into a rectangular shape and seam-welded; the weld is heat-treated and tested.
- Seamless: pierced from billet for higher pressure and closer tolerance (less common for large RHS).
- Cold forming: produces tight corners and good dimensional consistency; normalized or stress-relieved on request.
- Tolerance: EN 10219 (cold formed) or ASTM A500 dimensional classes per order.
Applications
- Building and warehouse structural frames
- Machine guards, enclosures, and bases
- Trailer and truck chassis members
- Greenhouse and agricultural structures
- Handrails, balustrades, and architectural facades
- Solar mounting and racking systems
Quality Assurance
- EN 10204 3.1 mill certificate with heat traceability
- Dimension and wall thickness check at multiple points
- Flattening and bend test for welded tube
- Surface inspection for scratches, dents, and seam quality
- Optional UT of seam, coating thickness, and third-party inspection
Packaging & Shipping
- Bundled with steel strapping and wooden separators
- End caps or plastic sleeve to protect edges
- Oiled or VCI-wrapped for sea freight
- Galvanized and painted finishes protected with film
- 20ft/40ft container or break-bulk loading with tally and photos
Huaxia-Steel supplies carbon steel rectangular tube (RHS) in Q235B, Q345B, SS400, S355JR, and A500 Grade B/C, ERW and seamless, plain or galvanized. Send us your size, wall, grade, and quantity for a same-week factory-direct quotation.
