Carbon steel tee classification

10# 20# A3 Q235A 20g 20G 16Mn ASTM A234 ASTM A105 ASTM A403 etc

Seamless tee DN15 to DN800 domestic general implementation of GB/T12459-2005 standards.

The larger one belongs to the seam welded tee, and the implementation standard is GB/T13401-2005.