Seamless Steel Tube

Seamless steel pipes for precision structures

GB/T 8162——Chinese standards
GB/T 3639——Chinese standards
Usage: Used for manufacturing seamless steel pipes for pipelines, containers, equipment, fittings, and mechanical structures
Main production steel pipe grades：10、20、35、45、Q345 Alloy steel, etc
Dimensional tolerance:

Steel pipe type	Outside diameter（D）		Steel pipe wall thickness（S）
Cold-drawn pipe GB/T 8162	Outer diameter of steel pipe	Allowable deviation	Steel pipe wall thickness	Allowable deviation
	(mm)	(mm)	(mm)	(mm)
	＞30～50	±0.3	≤30	±10％
	＞50～219	±0.8％	≤30	±10％
GB/T 3639 Cold rolled tube	≤32	±0.08		±10%
	32-40	±0.15		±10%
	42-50	±0.20		±10%
	50-60	±0.25		±10%
	62-670	±0.30		±10%

Mechanical：

Standard	Name of shop	Tensile strength （MPa）	Yield strength （MPa）	Elongation （％）
GB/T8162	10	≥335	≥205	≥24
	20	≥390	≥245	≥20
	35	≥510	≥305	≥17
	45	≥590	≥335	≥14
	Q345	≥490	≥325	≥21
	15CrMo	≥440	≥295	≥22
	12Cr1MoV	≥490	≥245	≥22
GB/T 3639 NBK	10	≥335	≥205	≥24
	20	≥440	≥245	≥20
	35	≥530	≥315	≥17
	45	≥600	≥335	≥14