In international trade, the most commonly used correspondence is:
- Q235B ≈ ASTM A53 Gr.B ≈ S235JR ≈ SS400
- Q355B ≈ ASTM A53 Gr.C ≈ S355JR ≈ STK500
| China GB/T |
USA ASTM |
EU EN |
Germany DIN |
Japan JIS |
Australia AS/NZS |
Int’l ISO |
|---|---|---|---|---|---|---|
| Q195 | Gr.A / A500 Gr.A | S195 | St33 | SS330 / STK290 | AS/NZS 1074 (Grade L) | — |
| Q215 | Gr.A / A283 C | S235 | St37-2 | SS330 | — | — |
| Q235 | Gr.B / A36 | S235JR | St42.2 | SS400 / STK400 | AS/NZS 1074 (M/H) / AS/NZS 1163 (C250) | E235B |
| Q275 | Gr.B | S275JR | St44-2 | SS490 | — | E275B |
| Q345 (Old) / Q355 (New) | Gr.C / A572 Gr.50 | S355JR | St52-3 | STK500 / SM490 | AS/NZS 1163 (C350) | — |
| Q390 | Gr.50 | S390 | — | — | — | — |
| Q420 | Gr.60 | S420 | — | — | — | — |
| Q460 | Gr.65 | S460 | — | — | AS/NZS 1163 (C450) | — |
| 10# / 20# | Gr.A / Gr.B | — | — | STPG370 / STPG410 | — | — |
Detailed Explanation of Each Standard System
American Standard (ASTM/API)
| Standard | Applicable Grade | Description |
|---|---|---|
| ASTM A53 | Gr.A, Gr.B, Gr.C | Welded/seamless pipe for fluid transmission |
| ASTM A500 | Gr.A, Gr.B, Gr.C | Round/square/rectangular structural tubes |
| ASTM A795 | — | Special pipe for fire sprinkler systems |
| API 5L | Gr.B, X42, X52, etc. | Oil & gas pipeline (sulfide corrosion resistance) |
| ASTM A36 | — | Carbon structural steel for building structures |
European Standard (EN)
| Standard | Applicable Grade | Description |
|---|---|---|
| EN 10255 | S195, S235 | Non-alloy steel pipes, suitable for threaded connection |
| EN 10219 | S235JR, S275JR, S355JR | Cold-formed welded structural hollow sections |
| EN 10025 | S235, S275, S355 | Hot-rolled structural steel products |
European standard designation meanings
- S = Structural steel
- 235/275/355 = Minimum yield strength (MPa)
- JR = Impact energy at room temperature (20°C) / J0 = 0°C / J2 = -20°C
German Standard (DIN)
| Grade | Equivalent GB Standard | Description |
|---|---|---|
| St37-2 | Q235B | Old grade, now replaced by EN standards |
| St42.2 | Q235B | Commonly used for steel pipes |
| St52-3 | Q345B/Q355B | Low alloy high strength steel |
| DIN 2440 | — | Standard for steel pipes with threaded connections |
Japanese Standard (JIS)
| Grade/Standard | Equivalent GB Standard | Description |
|---|---|---|
| SS330 / SS400 / SS490 | Q195 / Q235 / Q275 | Hot-rolled steel for general structural use |
| STK290 / STK400 / STK500 | Q195 / Q235 / Q345 | Special for steel pipe piles and structural tubes |
| STPG370 / STPG410 | 20# | Steel pipes for pressure piping applications |
| JIS G3444 | — | Standard for carbon steel pipes for general structural use |
Australia and New Zealand Standards
| AS/NZS Grade | Equivalent GB | Application |
|---|---|---|
| AS/NZS 1074 (Grade L) | Q195 | Light-duty fluid pipes, conduit pipes |
| AS/NZS 1074 (Grade M/H) | Q235B | General fluid pipes (water, gas, fire protection) |
| AS/NZS 1163 (C250) | Q235B | Building structures, guardrails, scaffolding |
| AS/NZS 1163 (C350) | Q355B | Heavy load-bearing structures, bridges |
| AS/NZS 1163 (C450) | Q420/Q460 | Ultra-high strength structures, heavy-duty machinery |
Key Notes
- AS/NZS 1074 primarily corresponds to fluid transport pipes, classified into three grades according to wall thickness: L (light), M (medium), and H (heavy).
- AS/NZS 1163 primarily corresponds to structural pipes; the numbers in the grade (e.g., C350) represent the minimum yield strength (MPa).
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