Generally, seamless pipes are made of 10, 20, 30, 35, 45 high-quality carbon steel, 16Mn, 5MnV low-alloy structural steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other alloy steels, hot-rolled or cold-rolled. Seamless pipes made of low-carbon steels such as 10 and 20 are mainly used for fluid delivery pipelines. Seamless pipes made of medium-carbon steels such as 45 and 40Cr are used to manufacture mechanical parts, such as the load-bearing parts of automobiles and tractors.

Generally, seamless pipes must ensure strength and flattening tests. Hot-rolled steel pipes are delivered in hot-rolled or heat-treated states; cold-rolled steel pipes are delivered in hot-rolled or heat-treated states. Seamless pipes for low and medium pressure boilers: used to manufacture various low and medium pressure boilers, superheated steam pipes, boiling water pipes, water-cooled wall pipes, and superheated steam pipes, large smoke pipes, small smoke pipes and arch brick pipes for locomotive boilers.

Seamless pipes are hot-rolled or cold-rolled (pulled) with high-quality carbon structural steel. Mainly made of No. 10 and No. 20 steel, in addition to ensuring the chemical composition and mechanical properties, water pressure tests, curling, flaring, flattening and other tests are required. Hot rolling is delivered in hot rolled state, cold rolling (drawing) is delivered in heat treated state.

Seamless pipe theoretical calculation formula:

(outer diameter – wall thickness) × wall thickness × 0.02466 = weight of seamless pipe per meter {kg}