Material:Q235B,SS400,Q345 I beam can be used in a variety of building structures,the bridge,the support and ... leg extends , waist thick. Secondly, I Beam is widely used in each kind of building structures, bridges, vehicles, supports, machineries ... steel market. Usage (1).used for a variety of building structures(2).used for the bridge, vehicle construction(3).used for the support, machinery and other ...