Carbon Steel Rectangular Tube — Factory Direct Supplier | Huaxia-Steel
Carbon steel rectangular tube (also called box section, RHS — rectangular hollow section) combines the strength of hollow structural profiles with the practical advantages of flat surfaces for connection, welding, and clamping. Huaxia-Steel supplies cold-formed and hot-finished rectangular tubes from 20×40mm to 400×200mm, in wall thicknesses 1.0-12mm, covering structural and mechanical applications.

Product Overview
Rectangular tubes are formed by cold-forming flat strip into a rectangular profile with a longitudinal ERW seam, or by hot-finishing (welded + normalized). Cold-formed tubes per ASTM A500/EN 10219 suit structural applications; hot-finished per EN 10210 provide tighter tolerances and superior mechanical uniformity.
| Specification | Range | Standard |
|---|---|---|
| Section Size (H×B) | 20×40 mm – 400×200 mm | ASTM A500, EN 10219 |
| Wall Thickness | 1.0 mm – 12 mm | Custom available |
| Length | 6 m standard; custom 3-12 m | Cut-to-length available |
| Surface | Black, galvanized, P&O | Per specification |
| Corner radius | Per standard (1.5t-3t typical) | ASTM A500 Section 8 |
Dimensions & Per-Meter Weight
| H×B (mm) | Wall (mm) | Weight (kg/m) | Section Area (cm²) | Standard |
|---|---|---|---|---|
| 20×40 | 1.5 | 1.31 | 1.66 | EN 10219 S235JR |
| 30×50 | 2.0 | 2.31 | 2.94 | EN 10219 S235JR |
| 40×60 | 2.0 | 2.93 | 3.73 | ASTM A500 Gr B |
| 50×100 | 3.0 | 6.61 | 8.42 | ASTM A500 Gr B |
| 60×120 | 3.0 | 8.01 | 10.2 | ASTM A500 Gr B |
| 80×120 | 4.0 | 12.0 | 15.2 | ASTM A500 Gr B |
| 100×150 | 4.0 | 15.0 | 19.1 | ASTM A500 Gr C |
| 100×200 | 5.0 | 22.4 | 28.5 | ASTM A500 Gr C |
| 150×250 | 6.0 | 36.5 | 46.2 | ASTM A500 Gr C |
| 200×300 | 8.0 | 60.5 | 76.7 | ASTM A500 Gr C |
| 300×400 | 10.0 | 103 | 131 | Custom / EN 10210 |

Available Grades
| Grade | Standard | Yield (MPa) | Tensile (MPa) | Typical Use |
|---|---|---|---|---|
| A500 Gr B | ASTM A500 | 315 min (rounds) | 400 min | General structural |
| A500 Gr C | ASTM A500 | 345 min | 425 min | Higher-strength structural |
| Q235B | GB/T 6728 | 235 min | 375-500 | General structural (China) |
| Q355B | GB/T 6728 | 355 min | 470-630 | Heavy structural (China) |
| S235JR | EN 10219 | 235 min | 360-510 | Structural (Europe) |
| S355J2H | EN 10219 | 355 min | 470-630 | Heavy structural (Europe) |
Manufacturing Standards
- ASTM A500: Cold-Formed Welded and Seamless Carbon Steel Structural Tubing in Rounds and Shapes — covers rectangular, square, and round shapes for structural use
- EN 10219-1/2: Cold-formed welded steel structural hollow sections — European standard with S235JR and S355J2H grades
- EN 10210-1/2: Hot-finished steel structural hollow sections — tighter dimensional tolerances, superior mechanical uniformity
- GB/T 6728: Structural hollow sections — Q235B, Q345B, Q355B for Chinese market and export
Applications
- Structural steelwork: Columns, beams, frames, trusses, bracing
- Industrial frameworks: Conveyor supports, equipment platforms, racking systems
- Architectural: Curtain wall mullions, canopy framing, signage structures
- Transport: Trailer frames, truck body structures, container reinforcement
- Agricultural: Barn frames, livestock enclosures, greenhouse structures
- Fencing & gates: Security fencing posts, gate frames, barrier systems
Quality Assurance
Every batch of rectangular tube includes:
- Mill Test Certificate (MTC) per EN 10204 3.1 — full chemical and mechanical traceability
- Dimensional inspection: Height, width, wall thickness, corner radius, straightness, length
- Weld seam integrity: Visual and ultrasonic weld inspection per client specification
- Third-party inspection: SGS, BV, TUV, or client-designated inspector available

Packaging & Shipping
Bundles of rectangular tube are strapped with steel bands at 3-4 points, interleaved with cardboard separators. Wooden dunnage at base. Standard 6m bundles in 20′ GP containers; longer lengths in 40′ HC. Surface options: black (as-formed), pickled & oiled, hot-dip galvanized. VCI wrap available for long transit.
Request a Quote
Huaxia-Steel provides factory-direct carbon steel rectangular tube with full certification, flexible surface finish options, and competitive FOB/CIF pricing. Contact our sales team with your section size, wall thickness, grade, and quantity for a quotation within 24 hours.





