Carbon steel pipes are divided into two categories: Hot-rolled and cold-rolled (drawn) steel pipes.

Hot-rolled carbon steel pipes are divided into general steel pipes, low and medium pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, geological steel pipes and other steel pipes.

In addition to general steel pipes, low and medium pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, and other steel pipes, cold-rolled (pulled) carbon steel pipes also include carbon thin-walled steel pipes, alloy thin-walled steel pipes, non-ferrous steel pipes, etc. Rust thin-walled steel pipe, special-shaped steel pipe. The outer diameter of hot-rolled seamless pipes is generally greater than 32mm, and the wall thickness is 2.5-75mm. The outer diameter of cold-rolled seamless pipes can reach 6mm and the wall thickness can reach 0.25mm. The outer diameter of thin-walled pipes can reach 5mm and the wall thickness is less than 0.25mm. Cold rolling has higher dimensional accuracy than hot rolling.

General carbon steel pipe: It is made of 10, 20, 30, 35, 45 and other high-quality carbon steel 16Mn, 5MnV and other low-alloy structural steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other alloy steel hot-rolled or cold-rolled. Seamless pipes made of low carbon steel such as 10 and 20 are mainly used for fluid transportation pipelines. 45, 40Cr and other medium carbon steel seamless pipes are used to manufacture mechanical parts, such as the stressed parts of automobiles and tractors. Generally, carbon steel pipes are used to ensure the strength and flattening test. Hot-rolled steel pipes are delivered in hot-rolled or heat-treated state; Cold-rolled steel pipes are delivered in heat-treated state.