| 標準化壁厚允許偏差 | |||||
| 偏差等級 | 壁厚允許偏差 | ||||
| S/D | |||||
| 0.1< S/D | 0.05< S/D≤0.1 | 0.025< S/D≤0.05 | S/D≤0.025 | ||
| S1 | ±15%,最小±0.6mm | ||||
| S2 | A | ±12.5%,最小±0.4mm | |||
| B | +正偏差取決于重量要求 - 12.5% | ||||
| S3 | A | ±10%,最小±0.2mm | |||
| B | ±10% | ±12.5%,最小±0.4mm | ±15% | ||
| C | +正偏差取決于重量要求 - 10% | ||||
| S4 | A | ±7.5%,最小±0.15mm | |||
| B | ±7.5% | ±10% | ±12.5% | ±15% | |
| S5 | ±5%,最小±0.10mm | ||||
| 非標準化壁厚允許偏差 | |||||
| 偏差等級 | 壁厚允許偏差,% | ||||
| NS1 | +15 -12.5 | ||||
| NS2 | +15 -10 | ||||
| NS3 | +12.5 -10 | ||||
| NS4 | +12.5 -7.5 | ||||
| 注:S是鋼管公稱壁厚,D是鋼管公稱外徑。 | |||||
| 標準化外徑允許偏差 | |
| 偏差等級 | 外徑允許偏差 |
| D1 | ±1.5%,最小±0.75mm |
| D2 | ±1.0%,最小±0.50mm |
| D3 | ±0.75%,最小±0.30mm |
| D4 | ±0.50%,最小±0.10mm |
| 非標準化外徑允許偏差 | |
| 偏差等級 | 外徑允許偏差,% |
| ND1 | +1.25 -1.50 |
| ND2 | ±1.25 |
| ND3 | +1.25 -1.0 |
| ND4 | ±0.8 |