... ,zinc plated,acid pickling light galvanized u frame steel beams1.Strictly quality control by 100% ... hardware, crane partsMaterialcarbon steel, stainless steel, aluminum alloy, copperProcedurewelding,stamping,cutting,punching,bending,grinding,machining,threadingSurface ... press machine, CNC machinery center, CNC laser-cut machine, CNC flame-cut machine, CNC bending machine, CNC boring machine, punching ...