Material:

High quality carbon structural steel(Chinese national steel grades): 10#, 15#, 20#, 25#, 35#, 45#, 20Mn, 25Mn......

Low alloy high strength structural steel(Chinese national steel grades): Q235, Q275, Q295, Q345 (16Mn), Q390, Q420, Q460, etc..

Alloy structural steel(Chinese national steel grades): 40Mn2, 45Mn2, 27SiMn, 40MnB and 45MnB, 20Mn2B, 20Cr, 30Cr and 35Cr, 40Cr, 45Cr and 50Cr, 38SiMn, 12CrMo, 15CrMo, 20CrMo and 35CrMo steel, 42CrMo, 12CrMoV and 12Cr1MoV and 38CrMoAl, 50CrVA, 20CrMn, 20CrMnSi, 30CrMnSI, 35CrMnSiA, 20CrMnTi, 30crmnti, 12CrNi2, 12crni3, 12Cr2Ni4, 40CrNiMoA, 45CrNIMnVA.

Frequently used materials for steel pipe is 20#, 45#, Q345B (16Mn), 40cr etc

Tolerance Of Outside Diameter

Hot rolling (hot expanding, hot extrusion) steel pipe: ±1% or ±0.50, using bigger one

Cold drawn (rolling) steel pipe: ±1% or ±0.30, using bigger one

Tolerance Of Wall Thickness