5101-31 Pipe or tube: Manufacturing - Iron or steel; Metal ejection molding
Applies to:
Businesses 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.
Products that use these pipes or tubes include, but are not limited to:
• Automotive exhaust systems;
• Oil lines;
• Water lines.
Processes for pipe or tube manufacturing include, but are not limited to:
• 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).
• 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.
• Metal ejection molding - 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.
Exclusions:
• Pipe dealers are classified in 2009;
• Installing products manufactured in this classification are classified in the classification applicable to the work being performed;
• Foundry operations are classified in 5103.
[Statutory Authority: RCW 51.04.020 and 51.16.035. WSR 25-23-070, s 296-17A-5101, filed 11/18/25, effective 1/1/26. WSR 07-01-014, recodified as § 296-17A-5101, filed 12/8/06, effective 12/8/06. Statutory Authority: RCW 51.16.035. WSR 98-18-042, § 296-17-661, filed 8/28/98, effective 10/1/98; WSR 85-24-032 (Order 85-33), § 296-17-661, filed 11/27/85, effective 1/1/86; WSR 83-24-017 (Order 83-36), § 296-17-661, filed 11/30/83, effective 1/1/84; Order 73-22, § 296-17-661, filed 11/9/73, effective 1/1/74.]