5101-31 Pipe or tube: Manufacturing - iron or steel; Metal ejection molding

     Applies to establishments engaged in the manufacture of pipe or tubes from iron or steel. This classification contemplates both seamed and seamless pipe and tubing involving either a hot or cold drawing process or roll forming and machine welding processes, as well as flexible steel tubing used for products such as, but not limited to, automotive exhaust systems, water lines, and oil lines. In the drawing process, metals are melted to a molten state in furnaces, then rolled or spun in rolling machines and a pipe or tube is drawn. Tubing may be annealed (fed through a furnace then slowly cooled to strengthen and reduce brittleness). In the roll forming method flat sheets of iron or steel are bent in brake presses or other rolling or bending machinery, then the edges are welded together to form the pipe or tube. This classification also includes metal ejection molding in which raw scrap and pig iron is melted, forced into casting machines, and cast in high speed revolving flasks of various shapes depending on the product being produced. When finished, products are ejected from the molds. They may be further processed by annealing, tumbling, deburring and grinding, and cleaned in acid baths.

     This classification excludes pipe dealers which are to be reported separately in classification 2009; the installation of any product manufactured in this classification which is to be reported separately in the classification applicable to the work being performed; and foundry operations which are to be reported separately in classification 5103.