Materials and Manufacture: The piles shall be made by the seamless,Website: ,electric resistance welded,flash welded or fusion welded process, the seams of welded pipe piles shall be longitudinal ,helical-butt,or helical-lap. Process: The steel shall be made by one or more of the following processses:open-hearth,basic-oxygen or electric-furnace. Chemical Composition. The steel shall contain no more than 0.050% phosphorous.