When sourcing structural steel pipes for global projects, understanding local standards is critical. GB/T 8162, from China, and ASTM A500, from the United States, are two widely used standards for structural tubing.
This article compares GB/T 8162 and ASTM A500 across scope, dimensions, steel grades, mechanical properties, tolerances, and whether one can replace the other.
Overview of Each Standard
| Aspect | GB/T 8162-2018 | ASTM A500 (2021) |
|---|---|---|
| Standard Name | Seamless Steel Tubes for Structural Purposes | Cold-Formed Welded and Seamless Carbon Steel Structural Tubing |
| Region | China | United States |
| Pipe Types | Seamless only (round default) | Seamless and ERW; round, square, and rectangular |
| Applications | General structural, mechanical, OEM uses | Building structures, bridges, towers, and load-bearing members |
| Impact Test | ❌ Not required by default | ❌ Optional (only if specified) |
| Weldability Index (Pcm) | ❌ Not required | ❌ Not required |
| CE Compliance | ❌ No | ❌ Not CE-compliant; used mainly in the US and Latin America |
📌 GB/T 8162 focuses on seamless pipes, while ASTM A500 covers both welded and seamless options and emphasizes hollow structural shapes (HSS).
Dimensional Requirements Comparison
| Parameter | GB/T 8162 | ASTM A500 |
|---|---|---|
| OD Range | 10 – 720 mm | 0.5 – 508 mm (0.5–20 in.) |
| Wall Thickness (WT) | 1 – 30 mm | 0.6 – 25 mm |
| Length | 5 – 12 m (custom available) | 6 – 12 m (random or fixed) |
| Shape | Round (default) | Round, square, rectangular |
| Corner Radius | Not standardized | Controlled for square/rectangular |
📌 ASTM A500 offers more variety of shapes, while GB/T 8162 focuses primarily on seamless round tubes (square/rectangular require customization).
Material Grades Comparison
| Standard | Common Grades | Yield Strength (MPa) |
|---|---|---|
| GB/T 8162 | Q235B, Q345B/C/D, Q460C/D, Q550D, Q690D | 235–690 MPa |
| ASTM A500 | Grade A, B, C, D | 230–345 MPa |
ASTM A500 Grades:
- Grade A: Min YS 228 MPa
- Grade B (most used): Min YS 290 MPa
- Grade C: Min YS 345 MPa
- Grade D (with impact): Min YS 345 MPa, impact at -20°F
📌 GB/T 8162 offers higher strength grades (Q460–Q690), more suitable for heavy machinery or OEM use. ASTM A500 focuses on consistency for construction-grade tubing.
Mechanical Properties
| Property | GB/T 8162 (e.g. Q345D) | ASTM A500 (Grade B/C) |
|---|---|---|
| Yield Strength | ≥345 MPa | 290–345 MPa |
| Tensile Strength | 470–630 MPa | 400–525 MPa |
| Elongation | ≥21% | 23–25% |
| Impact Energy | Optional | Optional (Grade D only) |
ASTM A500 does not mandate impact testing (except for Grade D). GB/T 8162 has no impact requirement, but mechanical grades can be customized.
Tolerances & Testing Requirements
| Requirement | GB/T 8162 | ASTM A500 |
|---|---|---|
| OD Tolerance | ±1.5% typical | ±0.75% for round |
| Wall Thickness Tolerance | ±12.5% | -10%, +10% |
| Straightness | ≤0.15% of length | ≤1/8 inch per 10 ft (~1 mm/m) |
| Flattening/Flaring | Required | Required |
| NDT | Optional | Optional unless specified |
| Corner Control | Not regulated | Strict for square & rectangular |
ASTM A500 enforces stricter geometric control on square/rectangular tubes, whereas GB/T 8162 applies broader tolerances more suitable for machining or fabrication use.
Can GB/T 8162 Replace ASTM A500?
Sometimes, but not always.
✅ It can replace ASTM A500 when:
- The project is non-standard, OEM machinery, or fabrication-focused
- The buyer accepts seamless round pipes instead of welded profiles
- No strict requirement for ASTM documentation or American certification
❌ It cannot replace ASTM A500 when:
- The design references HSS or specific ASTM specs
- Pipes are square/rectangular with tolerance-critical applications
- The project is based in the US or Latin American market with building code enforcement
Conclusion
GB/T 8162 is ideal for Chinese-made seamless structural pipes, especially in equipment manufacturing and heavy-duty applications with high-strength steel.
ASTM A500 is widely used in North American construction and favors consistency, shape variety, and weldability for building structures.
At YIGE Steel, we produce:
- GB/T 8162-compliant seamless round tubes (Q345–Q690, 10–720 mm OD)
- Square/rectangular shaped tubes via cold drawing or welding
- ASTM A500-equivalent shapes on request with tight tolerance
📩 Need advice on matching standards or dimensions? Contact us at stella.yu@yige-steel.com
