What are the main steel grades of general use seamless steel pipe

The general use seamless steel pipe is hot-rolled or cold-rolled steel pipe made of high-quality carbon steel, low-alloy structural steel or alloy steel.

The main steel grades of high-quality carbon steel are grade 10, 20, 35, 45 (10#, 20#, 35#, 45#), AISI 1020, AISI 1045, S20C, S45C, etc. The 10# seamless steel pipe and 20# seamless steel pipe are mainly used for fluid transportation pipeline.

The main steel grades of low-alloy structural steel are Q345B, Q345D, S355JR, S355J2, A572 grade 50, SM490YA, SM490YB, etc.

The main steel grades of alloy steel are 40Cr, 30CrMnSi, 40MnB, AISI 4130, AISI 4140, 20Cr, 40Cr, 27SiMn, 20CrMo, 35CrMo, 25CrMo4, 30CrMo4, 34CrMo4, 42CrMo4, etc. The 40Cr seamless steel pipe is usually used to make mechanical parts, such as the stressed parts of automobiles and tractors.

Generally, the strength and flattening test of general use seamless steel pipe shall be ensured. Hot rolled steel pipes are delivered in hot rolled or heat treated condition; cold rolled pipes are delivered in heat treated condition.