1.1, hot rolled seamless tubes in automatic rolling unit production. Check for and remove solid billet surface defects, cut into desired lengths, centering on the perforated tube end to end, and then sent to the furnace heat, perforated in the punch. Piercing while continuing to rotate and move forward, in rolls and head under the formed cavity within the tube, capillary. Then sent to the automatic mill continued to roll on. Finally the whole wall thickness, warp sizing machine sizing, meet the specification requirements. Production hot-rolled seamless steel tube continuous rolling method is more advanced.
1.2, if you desire to get better quality and smaller size of seamless pipe, cold rolling, cold-drawing must be used or a combination of methods. Cold rolling is usually conducted in two-roller rolling mill, steel tapered round slot and fixed cone composed of the head of the ring groove rolling. Cold drawn usually in 0.5~100T single-chain-or double-stranded in the cold-drawing machine.
1.3, is heated by extrusion extrusion of tube placed in a closed cylinder, perforated bar movement with the extruded rod, extruded parts extruded from a smaller die. This method can produce a smaller diameter pipe. Seamless steel tubes use: mainly used as transmission fluid pipe or structural parts.
Pipe joints using steel plate (steel) two welded together, so cheap, widely used.
Seamless steel tubes for mechanical industries, steel for the construction industry. But deals with pressure pipe seamless steel tubes.