Cold-drawn precision tube The metal is elongated using a cold drawing machine without heating. The advantage is that it does not require high temperatures, but the disadvantage is that there is significant residual stress, and it cannot be drawn too long. Cold drawing can improve toughness and tensile strength, resulting in better mechanical properties. The cold-drawing process of precision tubes: round tube blank → heating → perforation → heading → annealing → acid pickling → oil coating (copper plating) → multiple cold drawing passes (cold rolling) → blank tube → heat treatment → straightening → hydrostatic test (ultrasonic testing) → marking → warehousing. Cold-drawn precision steel tube It is a high-precision steel tube produced by cold drawing or hot rolling. Because there is no oxide layer on the inner and outer walls of the steel tube, it can withstand high pressure without leakage, has high accuracy and high surface finish, does not deform during cold bending, and has no cracks when expanded or flattened. Therefore, it is mainly used to produce hydraulic or pneumatic components such as cylinders or oil cylinders, and can also be used as a seamless tube. Characteristics of cold-drawn precision steel tubes: smaller outer diameter; high accuracy for small batch production; high precision for cold-drawn finished products, good surface quality; the more complex cross-sectional area of the steel tube. The steel tube has superior performance, and the metal is denser.