hot and cold seamless steel pipe
PIC-(hot and cold seamless steel pipe)
| Type of steel tube | Steel tube size | Deviation | ||
| mm | Ordinary grade | Senior | ||
| Hot rolling (extrusion, expansion) tube | Outside diameterD | All | +1%（Minimum+0.50） | - |
| Wall thicknessS | All | +15%（Minimum+0.45） | - | |
| -12.5%（Minimum-0.40） | ||||
| Cold drawing (rolling) tube | Outside diameterD | 6~10 | 0.2 | 0.15 |
| >10~30 | 0.4 | 0.2 | ||
| >30~50 | 0.45 | 0.3 | ||
| >50 | 1% | 0.80% | ||
| Wall thicknessS | ≤1 | 0.15 | 0.12 | |
| >1~3 | 15% | 12.50% | ||
| -10% | -10% | |||
| >3 | 12.50% | 10% | ||
| -10% | ||||
| Note: the outer diameter is not less than 351mm of the thermal expansion tube, the wall thickness allows the deviation of +18% | ||||