Cold drawn steel pipe is a kind of steel pipe, which is classified according to different production processes. In the process of expanding the diameter of the capillary tube or the raw material tube, it is formed by multiple passes of cold drawing, usually on a single-chain or double-chain cold drawing machine of 0.5 to 100T. Cold-rolled steel pipes are divided into general steel pipes, low-medium pressure boiler steel pipes, high-pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, mechanically processed pipes, thick-walled pipes, small-diameter pipes and internal-mold cold-drawn pipes. The outer diameter of the drawn steel pipe can be up to 6mm, the wall thickness can be up to 0.25mm, and the outer diameter of the thin-walled pipe can be up to 5mm. The wall thickness is less than 0.25mm. The accuracy and surface quality are significantly better than hot-rolled pipe expansion.