There are six main processing methods for seamless pipes (SMLS):
    
1. Forging method: Use a swage forging machine to stretch the end or part of the pipe to reduce the outer diameter. Commonly used swage forging machines include rotary type, connecting rod type, and roller type.

2. Stamping method: Use a tapered core on the punching machine to expand the tube end to the required size and shape.

3. Roller method: place a core in the tube, and push the outer circumference with a roller for round edge processing.
4. Rolling method: Generally, no mandrel is needed, and it is suitable for the inner round edge of thick-walled tubes.
5. Bending method: There are three commonly used methods, one method is called expansion method, the other method is called stamping method, and the third method is roller method. There are 3-4 rollers, two fixed rollers, and one adjustment roller. With a fixed roll pitch, the finished pipe is tortuous.
6. Bulging method: One is to place rubber inside the pipe, and use a punch to tighten the top to make the pipe protrude; the other method is hydraulic bulging, filling the middle of the pipe with liquid, and the liquid pressure bulges the pipe into the desired shape. Most of the shape and output of corrugated pipes are the best methods.

According to the different processing temperatures of seamless steel pipes, seamless steel pipes are divided into cold working and hot working.

Hot-rolled seamless steel pipe: heat the round tube billet to a certain temperature first, then perforate it, then go to continuous rolling or extrusion, then go to stripping and sizing, then cool down to the billet tube and straightening, and finally It is to carry out procedures such as flaw detection experiments, marking, and warehousing.

Cold-drawn seamless steel pipe: heating, piercing, heading, annealing, pickling, oiling, cold rolling, billet tube, heat treatment, straightening, flaw detection and other procedures for the round tube billet.