what is cold drawn seamless tube

Cold drawn seamless pipe is a seamless steel pipe with high dimensional accuracy and good surface finish for precision mechanical structures, hydraulic equipment or reinforced sleeves.

Difference between cold drawn seamless steel pipe and hot rolled seamless steel pipe
The production process of cold-rolled seamless steel pipe is generally more complicated than hot-rolling. The tube blank must first be subjected to three-roll continuous rolling, and the sizing test should be performed after extrusion. If the surface does not respond to cracks, the round pipe will be cut by a cutter. Cut into billets of about one meter in length. Then enter the annealing process. Annealing should be acid-washed with an acidic liquid. When pickling, pay attention to whether there is a large amount of blistering on the surface. If there is a large amount of blistering, the quality of the steel pipe does not reach the corresponding standard. The appearance of cold-rolled seamless steel pipe is shorter than that of hot-rolled seamless steel pipe. The thickness of cold-rolled seamless steel pipe is generally smaller than that of hot-rolled seamless steel pipe, but the surface looks brighter than thick-walled seamless steel pipe. It's rough, and it doesn't have too much burr.

The main advantages of cold rolled steel pipes
The reduction ratio of cold-rolled steel pipe section is large, especially the wall reduction ability is strong. For carbon steel, the reduction rate of cross section in one rolling can reach 80% to 83%, and alloy steel can reach 72% to 75%. Its main disadvantage is the difficulty of changing tools. In addition to being directly used to produce a part of cold rolled tubes with high accuracy, the cold rolling method is often used in combination with the cold drawing method to open the billet for cold drawing. In this way, both the wall reduction ability of cold rolling can be brought into full play, and the advantages of easy replacement of cold drawn tools can be used cleverly, which is conducive to improving productivity, expanding the production range of products, and improving the surface quality of steel pipes.