
| 鋼管的內(nèi)徑及其允許偏差 | 鋼管的壁厚及其允許偏差 | ||||
| 外徑/mm | 壁厚/mm | 內(nèi)徑及其允許偏差/mm | 類別 | 壁厚/mm | 允許偏差/mm | 
| 50 63.5 | 2.5 1.6 | 45±0.12 60.30±0.14 | I | 1 <3.0 | +0.20 -0.10 | 
| 63.5 68.9 | 2.5 2.3 | 58.50±0.14 64.30±0.20 | >3.0-4.0 | +0.25 -0.15 | |
| 76 89 | 2.5 2.5 | 7l±0.20 84±0.25 | >4.0 | ±0.25 | |
| 89 89 | 4.0 5.0 | 8l±0.25 79±0.30 | Ⅱ | 1.6-3.6 | ±0.12 | 
| 100 100 | 4.0 6.0 | 92±0.30 88±0.35 | Ⅲ | ||