a36 carbon steel 1.Got nine countries factory approval 2.certification:CE ISO 3.Material:Q235,Q345,A36,ss400,st37-2 a36 carbon steel / steel channel1.ISO9001 Quality System Certificate 2.Got nine countries factory approvalWe offer high quality channel steel 1.Material: Q235,Q345,SS400,Q195,SS400,ASTMA362.Specification: 5 -40# 3.Length: 6M 9M 12M4.Standard:GB,ASTM,DIN,JIS,BS 5.Thickness:4.5mm~14. ...