... -grades steel truss system in longitudinal andlateral direction,and roof bracing system:1. The main truss node adopts welded H steel ... H steel,BS5950,50 Grade,British Standard;3. The roof bracing system adopts hot-rolled square tube and circular tube , BS5950 ... ! Straight cross-section or VariableCross-section!5) Bracing: X or V or other type bracing made from angle, round pipe, etc6) C ...