The material of the nail pile is steel #25
#25 The surface of the steel should be clean, stained with oil, dirt, and floating rust. Before use, it should be combined with the cold drawing process to remove rust and clean.
It is #25 steel straightening, it can be straightened by mechanical or manual. After straightening, it is used for tipping and eye-catching.
It is an auxiliary support for the underlying steel reinforcement at the bottom of the building.