Low-Priced ASTM A53 A106 Gr.B Low-Carbon Steel Seamless Tubes from China Suppliers | Factory Direct Hot-Rolled MS Round Tubes

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

Hot-rolled carbon steel pipes include 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 (drawn) carbon steel pipes, in addition to the 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, also include carbon thin-walled steel pipes, alloy thin-walled steel pipes, stainless thin-walled steel pipes, and special-shaped steel pipes. Hot-rolled seamless pipes generally have an outer diameter greater than 32mm and a wall thickness of 2.5-75mm. Cold-rolled seamless steel pipes can have an outer diameter down to 6mm and a wall thickness down to 0.25mm. Thin-walled pipes can have an outer diameter down to 5mm and a wall thickness less than 0.25mm. Cold-rolled pipes have higher dimensional accuracy than hot-rolled pipes.

General carbon steel pipes are made from high-quality carbon structural steels such as 10, 20, 30, 35, and 45, low-alloy structural steels such as 16Mn and 5MnV, or alloy steels such as 40Cr, 30CrMnSi, 45Mn2, and 40MnB, through hot rolling or cold rolling. Seamless pipes made from low-carbon steels such as 10 and 20 are mainly used for fluid transportation pipelines. Seamless pipes made from medium-carbon steels such as 45 and 40Cr are used to manufacture mechanical parts, such as load-bearing parts for automobiles and tractors. General-purpose carbon steel pipes must guarantee strength and pass flattening tests. Hot-rolled steel pipes are delivered in hot-rolled or heat-treated condition; cold-rolled pipes are delivered in heat-treated condition.