Hot-rolled seamless steel pipes are generally produced under automatic rolling mills. After inspection and removal of surface defects, the solid core finishing pipe is cut into lengths, and the surface layer of the broken hole end of the finishing pipe is relieved, and then sent to the heat treatment equipment to heat up, and the holes are broken on the piercing machine. In addition to the continuous rotation and forwarding of the hole, under the action of the hot-rolled strip and the top, the interior of the finishing tube gradually forms an inner wall, which is called a capillary tube.
 
    And then sent to the automatic rolling mill for cold rolling. All the machines and equipment have the entire wall thickness, and the die opening of the sizing machine exceeds the model specification requirements. The use of tubular rolling mills to produce hot-rolled seamless steel pipes is a better method than the older generation. In order to obtain seamless steel pipes with smaller specifications and higher quality, cold rolling, cold drawing or a combination of the two methods are indispensable. Cold rolling is generally carried out in a two-roll continuous extruder.
 
    Seamless steel pipes are cold rolled in annular welded bolts consisting of variable cross-section circular holes and fixed tapered tops. Cold drawing is generally carried out in 0.5~100T polypeptide chain type or double push rod type cold drawing machine. The extrusion processing method is to put the heated finishing tube into the closed extrusion processing cylinder, and the hole breaking rod and the extrusion processing rod exercise together to make the extrusion processed part extruded from the smaller die hole. . This method can produce seamless steel pipes with smaller diameters.
 
    Seamless steel pipes are made of stainless steel castings or solid-core precision-rolled pipes through holes to make capillaries, and then hot rolled, cold rolled or cold drawn. Seamless steel pipe has an important reputation in my country's seamless steel pipe industry. According to incomplete data analysis, there are more than 240 seamless steel pipe processing and manufacturing industries in China at this stage, more than 250 sets of seamless steel pipe diesel generators, and an annual production capacity of about 4.5 million tons.