The outer diameter of hot-rolled seamless pipe is generally greater than 32mm, and the wall thickness is 2.5-200mm. The outer diameter of cold-rolled seamless steel pipe can reach 6mm, and the wall thickness can reach 0.25mm. The outer diameter of thin-walled pipe can reach 5mm and the wall thickness is less than 0.25mm.

Generally used seamless steel pipe is made of 10, 20, 30, 35, 45 and other high-quality carbon bonded steel 16Mn, 5MnV and other low alloy structural steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other bonded steel hot rolled or cold rolled.10, 20 and other low carbon steel manufacturing seamless pipe is mainly used for fluid pipeline.45, 40Cr and other medium carbon steel made of seamless pipe to manufacture mechanical parts, such as cars, tractors stressed parts.The general use of seamless steel pipe to ensure the strength and flattening test.Hot rolled steel pipes are delivered in hot rolled or heat treated condition.Cold rolled delivery is heat – treated.