The process of thickening the spiral welded pipe is: pipe end heating (in slot furnace or induction heater) → thickening (with horizontal forging machine or hydraulic forging machine) → cooling → inspection. According to the size of the thickened tube, the thickening form and the thickening compression amount, the heating times and thickening passes are also different. There is one heating for one thickening, or one heating for two thickening. In order to eliminate the uneven performance of the thickened end and the pipe body caused by thickening, the spiral welded pipe usually needs to be heat treated as a whole after thickening. The failure of the drill pipe during use mainly occurs in the transition area between the thickened end and the pipe body. Therefore, the size of the transition area is very important.

Pipe end strengthening heat treatment, that is, through heat treatment, the strength of the wire part of the pipe end is one level higher than the strength of the pipe body. The tube end strengthening heat treatment process includes tube end heating, quenching (the medium is compressed air, water mist, etc.) and tempering.

Pipe end chamfering is used for pipelines conveying minerals, gas, oil, water and other media, and is usually welded one by one by spiral welded pipes. In order to facilitate the welding between pipes, the outer corner of the pipe end needs to be chamfered. According to the different uses of the spiral welded pipe, the size of the α angle and the value of the blunt edge ζ are also different, generally α=3. In order to ensure the accurate dimensions of α and ζ after the pipe end is chamfered, the out‑of‑roundness and uneven wall thickness of the spiral welded pipe are required to be as small as possible. When the spiral welded pipe factory is processing the pipe end, the chamfering of the pipe end and the cutting of the spiral welded pipe are carried out on the same machine tool. The most advanced pipe cutting machines in the world all have the function of chamfering. The processing of oil pipe couplings is completed on a special machine tool, and other processes are similar to pipe end processing except for the cutting to length of the coupling material.