Carbon Steel Round Tube — Factory Direct Supplier | Huaxia-Steel
Carbon steel round tube (also called circular hollow section, CHS) is one of the most versatile structural steel products — used in construction frameworks, mechanical tubing, handrails, scaffolding, and fluid conveyance. Huaxia-Steel supplies cold-formed and hot-finished carbon steel round tubes in OD 10-300mm with wall thicknesses from 0.5-12mm, available in A36, Q235B, S235JR, 1020, and other common grades.

Product Overview
Our carbon steel round tubes are manufactured by cold-forming (ERW/helical seam) or hot-finishing (seamless or HF-welded + normalized), depending on the application requirements. Cold-formed tubes per ASTM A500 are ideal for structural applications; hot-finished tubes per ASTM A513/A519 offer superior dimensional accuracy and mechanical properties for mechanical and pressure applications.
| Specification | Range | Standard |
|---|---|---|
| Outside Diameter | 10 mm – 300 mm | ASTM A500, A513 |
| Wall Thickness | 0.5 mm – 12 mm | Custom available |
| Length | 6 m standard; custom 3-12 m | Cut-to-length available |
| Surface | Black, galvanized, pickled & oiled | Per specification |
| End finish | Plain end, threaded, beveled | Per order |
Dimensions & Per-Meter Weight
| OD (mm) | Wall (mm) | Weight (kg/m) | Section Area (cm²) | Standard |
|---|---|---|---|---|
| 21.3 | 2.0 | 0.95 | 1.21 | ASTM A500 Gr B |
| 26.8 | 2.0 | 1.23 | 1.56 | ASTM A500 Gr B |
| 33.5 | 2.5 | 1.94 | 2.47 | ASTM A500 Gr B |
| 42.3 | 2.5 | 2.50 | 3.18 | ASTM A500 Gr B |
| 48.3 | 3.0 | 3.33 | 4.23 | ASTM A500 Gr B |
| 60.3 | 3.0 | 4.22 | 5.37 | ASTM A500 Gr B |
| 76.1 | 3.2 | 5.75 | 7.29 | ASTM A500 Gr B |
| 88.9 | 3.2 | 6.79 | 8.62 | ASTM A500 Gr B |
| 114.3 | 3.6 | 9.54 | 12.1 | ASTM A500 Gr B |
| 168.3 | 4.0 | 16.2 | 20.5 | ASTM A500 Gr B |
| 219.1 | 5.0 | 26.6 | 33.7 | ASTM A500 Gr B |
| 273.0 | 5.0 | 33.0 | 41.9 | ASTM A500 Gr B |

Available Grades
| Grade | Standard | Yield (MPa) | Tensile (MPa) | Typical Use |
|---|---|---|---|---|
| A500 Gr B | ASTM A500 | 315 min | 400 min | Structural, general |
| A500 Gr C | ASTM A500 | 345 min | 425 min | Higher-strength structural |
| A513 Type 1 | ASTM A513 | — | 330 min | Mechanical tubing (DOM) |
| A513 Type 5 | ASTM A513 | — | 480 min | Mechanical tubing (HREW) |
| Q235B | GB/T 3094 | 235 min | 375-500 | General structural (China) |
| S235JR | EN 10210/10219 | 235 min | 360-510 | Structural (Europe) |
| 1020 | SAE J403 | — | 395 min | Mechanical tubing |
Manufacturing Standards
- ASTM A500: Standard Specification for Cold-Formed Welded and Seamless Carbon Steel Structural Tubing in Rounds and Shapes — the primary standard for structural round tube in North America
- ASTM A513: Standard Specification for Electric-Resistance-Welded Carbon and Alloy Steel Mechanical Tubing — covers DOM (drawn-over-mandrel) and HREW (hot-rolled ERW) mechanical tubing
- EN 10219: Cold-formed welded structural hollow sections (S235JR, S355J2H) — European standard for structural tubing
- EN 10210: Hot-finished structural hollow sections — European standard for higher-tolerance structural tubing
- GB/T 3094 / GB/T 6728: Chinese standards for cold-formed and hot-finished hollow sections (Q235B, Q345B, Q355B)
Applications
- Structural construction: Columns, beams, trusses, canopy supports, handrails
- Mechanical tubing: Shaft housings, bushings, cylinder sleeves, pivot points
- Scaffolding: Scaffold tubes, brace members, temporary supports
- Fluid conveyance: Low-pressure water, air, and gas distribution (non-critical service)
- Agricultural: Greenhouse frames, livestock enclosures, irrigation supports
- Furniture & consumer: Table legs, chair frames, recreational equipment
Quality Assurance
Every batch of carbon steel round tube from Huaxia-Steel includes:
- Mill Test Certificate (MTC) per EN 10204 3.1 — chemical composition, mechanical properties, dimensional verification
- Hydrostatic or ultrasonic testing per standard requirement (A500 does not require; client specification may)
- Dimensional inspection: OD, wall thickness, length, straightness per standard tolerance
- Third-party inspection available: SGS, BV, TUV, or client-designated inspector

Packaging & Shipping
Round tubes are bundled with steel strapping at 3-4 points, separated by wooden spacers to prevent surface contact. Standard bundle length: 6m. Plastic end caps available to protect tube ends. Options include P&O surface, VCI paper wrap, and galvanized finish. Container loading: 20′ GP for 6m bundles, 40′ HC for longer lengths.
Request a Quote
Huaxia-Steel supplies carbon steel round tube with full certification, flexible packaging, and competitive FOB/CIF pricing for global markets. Contact our team with your OD, wall thickness, grade, and quantity requirements for a detailed quotation.





