Wall thickness tolerance of seamless steel pipe

Seamless pipes are extensively applied for the nuclear device, gas, petrochemical, ship building and boiler industries. seamless pipes dominates 65% of market share in Chinese boiler industry.

Types Sizes allowed tolerance
Ordinary steel pipe
Senior steel pipe
Hot rolled
Out diameter <50 ± 0.50 mm
± 0.40 mm
≥50 ± 1 %
± 0.75 %
Wall thickness <4 ± 12.5 %
± 10 %
4-20 +15%
-12.5%

± 10 %
≥20
± 12.5 %
± 10 %
Cold drawn Out diameter
6-10 ± 0.20 mm 
± 0.10 mm
>10-30 ± 0.40 mm
± 0.20 mm
>30-50 ± 0.45 mm
± 0.25 mm
>50 ± 1 %
± 0.5 %
Wall thickness ≤1
± 0.15 mm
± 0.12 mm
1-3 + 15 %
- 10 %
± 10 %
>3 + 12.5
- 10 %
± 10 %



Seamless pipe Specification, standard and identification

Seamless pipes are extensively applied for the nuclear device, gas, petrochemical, ship building and boiler industries. Seamless pipes dominates 65% of market share in Chinese boiler industry.