(1) Tube material supply, the tube materials used are hot-rolled finished or semi-finished tubes, extruded tubes and welded tubes; (2) Tube material preparation, including inspection, bundling, pickling, cleaning, rinsing, neutralizing and baking Dry, apply lubricant, etc .;
(3) Cold working (cold rolling or cold drawing);
(4) Finishing of finished products includes heat treatment, straightening, sampling, head and tail cutting, inspection (manual inspection and various flaw detection), hydrostatic testing, oiling, packaging, storage, etc. Different products have different finishing contents.