Seamless tubes are commonly made from carbon structural steels like 10, 20, 30, 35, 45, low-alloy steels such as 16Mn and 5MnV, or alloy steels like 40Cr, 30CrMnSi, 45Mn2, and 40MnB, through hot rolling or cold rolling processes. Seamless tubes made from low-carbon steels like 10 and 20 are primarily used for fluid conveyance pipelines. Seamless tubes made from medium-carbon steels such as 45 and 40Cr are used to manufacture mechanical parts, such as load-bearing components for cars and tractors.

General seamless tubes require strength and flattening tests. Hot-rolled steel tubes are delivered in a hot-rolled or heat-treated condition; cold-rolled in a heat-treated state. Seamless tubes for low and medium pressure boilers: Used for manufacturing various low and medium pressure boilers, superheated steam pipes, water tubes, water-cooled wall tubes, and superheated steam pipes for locomotive boilers, large flue pipes, small flue pipes, and arch brick tubes, etc.

Structural pipes, this standard applies to seamless steel pipes used in general and mechanical structures, while the fluid seamless steel pipe standard applies to general seamless steel pipes used for conveying fluids. The main difference between it and structural seamless steel pipes is that fluid seamless steel pipes undergo liquid pressure testing or ultrasonic, eddy current, and magnetic particle inspection individually. Therefore, it is not advisable to use fluid seamless steel pipes for pressure pipeline steel pipe standards. Seamless steel pipes are indicated by their outer diameter and wall thickness. Thick-walled seamless steel pipes are mainly used for mechanical processing, coal mining, hydraulic steel, and various other applications. The materials of thick-walled seamless steel pipes are divided into 10#, 20#, 35#, 45#, 16Mn, 27SiMn, 12Cr1MoV, 10CrMo910, 15CrMo, 35CrMo, etc. Thick-walled seamless steel pipes are categorized into hot-rolled, cold-rolled, cold drawn, extruded, and jacking pipes. Structural stainless steel seamless steel pipes (GB/T14975-1994) are hot-rolled (extruded, expanded) and cold-drawn (rolled) seamless steel pipes made of stainless steel, widely used in corrosion-resistant pipelines and structural components and parts in industries such as chemicals, petrochemicals, light industry, food, and machinery.