Light duty longspan racks are a highly versatile structural system that can be widely used to assemble lightweight racks, work benches, tool carts, suspension systems, safety nets and support frames. The length of the punched angle steel can be quickly cut according to the scale, assembled, modified and re-installed with screws, so that it can meet the needs of careful planning and emergency use. The lightweight punching shelf is a highly versatile structural system that can be widely used to assemble lightweight racks, work benches, tool carts, suspension systems, safety nets and support frames. The length of the punched angle steel can be quickly cut according to the scale, assembled, modified and re-installed with screws, so that it can meet the needs of careful planning and emergency use.