The production process of thick-walled seamless steel tubes can be divided intoCold Drawn、Cold Rolled、Hot-rolled、Hot ExpansionFour basic methods, steel pipes with materials of 10#, 20#, 35#, and 45# are called ordinary steel pipes, and are classified according to their applications.Structural Seamless Steel PipeSeamless steel tubes for conveyance useBoiler Seamless Steel PipeBoiler gradeHigh-pressure Seamless Steel Pipe；High-pressure seamless steel pipe for equipmentGeological drillingSeamless steel tubePetroleumSeamless steel tube for drilling；Seamless steel tubes for oil cracking；Seamless Steel Tubes for ShipbuildingCold drawn, cold rolledPrecision Seamless Steel PipeVarious alloy pipes. Seamless steel tubes are denoted by their outer diameter and wall thickness. Thick-walled seamless steel tubes are mainly used for mechanical processing, coal mining, hydraulic steel, and various other applications.