Carbon Steel I-beam 1. Standard: GB&JIS 2. Grade: Q235B,SS400 3. ... : normal 10m and 12m 4.Tolerance:3-10% Carbon Steel I-beam1)Material:SS400,ST37-2,A36,S235JRG1,Q235,Q345 etc ... steel, bridge and hull used structural steel and weathering steel. I-beam steel: 10a-56c; U-channel steel: 10a-40c and ... manufacture a variety of steel the customer wanted. Carbon Steel I-beam