Carbon steel pipes are divided into hot rolling and cold rolling (pulling) 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.
Cold-rolled (dial) carbon steel pipe is divided into general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, petroleum cracking pipe, other steel pipes, and also includes carbon thin-walled steel pipe, alloy thin-walled steel pipe, Rust thin-walled steel pipe, special-shaped steel pipe. The outer diameter of hot-rolled seamless pipe is generally larger than 32mm, the wall thickness is 2.5-75mm, the outer diameter of cold-rolled seamless steel pipe can be up to 6mm, the wall thickness can be up to 0.25mm, the outer diameter of thin-walled pipe can be 5mm, and the wall thickness is less than 0.25mm. Cold rolling is more accurate than hot rolling.
General carbon steel pipe: It is made of low-alloy structural steel such as 16Mn, 5MnV, such as 10, 20, 30, 35, 45, etc., or alloy steel such as 40Cr, 30CrMnSi, 45Mn2, 40MnB, etc., which is hot rolled or cold rolled. Seamless pipes made of low carbon steel such as 10 and 20 are mainly used for fluid conveying pipes. 45, 40Cr and other medium carbon steel seamless pipes are used to make mechanical parts, such as the force parts of automobiles and tractors. Generally, carbon steel pipes are required to ensure strength and flattening test. The hot rolled steel pipe is delivered in a hot rolled state or a heat treated state; the cold rolling is delivered in a heat treated state.