Seamless steel pipe size tolerance
Seamless steel pipe size tolerance
Seamless steel pipe outside diameter tolerance
1. Allowable deviation of outer diameter
Standardized outside diameter allowable deviation
Standardized outside diameter allowable deviation
| Deviation level | Standardized outside diameter allows partial |
| D1 | ±1.5%.min±0.75 mm |
| D2 | ±1.0%. min±0.50 mm |
| D3 | ±0.75%.min±0.30 mm |
| D4 | ±0.50%.min±0.10 mm |
Non-normalized outside diameter allowable deviation
| Deviation level | Non-normalized outside diameter allowable deviation |
| ND1 |
+1.25 -1.50 |
| ND2 | ±1.25 |
| ND3 |
+1.25 -1.O |
| ND4 | ±0.8 |
2．Special use of steel and cold-rolled (pull) steel pipe diameter deviation can be used absolute deviation.
2.1 Wall thickness allows deviation
Wall thickness tolerance is divided into both standardized and non-standardized. Priority should be given to the choice of standardized wall thickness
| Deviation level | Wall thickness allows deviation | ||||||
| S/D | |||||||
| 0.1< S／D | O．05<S／D≤0.1 | 0.025<S／D≤0.05 | S/D≤0.025 | ||||
| S1 | ±15%,min±0.6 mm | ||||||
| S2 | A | ±12.5%，min±0.4 mm | |||||
| B | + The positive deviation depends on the weight requirement -12.5 | ||||||
| S3 | A | ±10%,min±0.2mm | |||||
| B | ±10% | ±12.5% | ±15% | ||||
| min±0.4mm | |||||||
| C | + The positive deviation depends on the weight requirement -10% | ||||||
| S4 | A | ±7.5%, min±0.15 mm | |||||
| B | 士7.5% | 士10% | ±12.5% | ±15% | |||
| min士0.2 mm | |||||||
| S5 | ±5%，min士0.10 mm | ||||||
| Note: S is the nominal wall thickness of steel pipe, D is the nominal diameter of steel pipe. | |||||||
2.2 Recommended non-standardized wall thickness allows deviation
| Deviation level | Non-standardized wall thickness allows deviation% |
| NSl |
+15 -12.5 |
| NS2 |
+15 -10 |
| NS3 |
+12.5 -10 |
| NS4 |
-12.5 -7.5 |
2.3 Special use of steel and cold-rolled (pull) steel pipe wall thickness tolerance can be used absolute deviation.
