Seamless pipe is long steel with a hollow section and no joints on the periphery. According to the metallographic structure of stainless steel, it can be divided into semi-ferritic and semi-martensitic stainless steel seamless pipe, martensitic stainless steel seamless pipe, Austenitic Stainless Steel Seamless Pipe austenitic-ferritic iron-based stainless steel seamless pipe, etc.

According to the provisions of GB14975-2002 "Stainless Steel Seamless Steel Tubes", steel tubes usually have a length (indefinite length) of hot-rolled steel tubes of 1.5-10m, and hot-extruded steel tubes are equal to and greater than 1m. For cold-drawn (rolled) steel pipes with a wall thickness of 0.5-1.0mm, 1.0-7m; for those with a wall thickness greater than 1.0mm, 1.5-8m.

The thicker the wall thickness of the austenitic stainless steel seamless pipe, the more economical and practical it is, and the thinner the wall thickness, the greater the processing cost.

The performance strength of Super Austenitic Stainless Steel Seamless Pipe and Tube is stronger than that of austenitic stainless steel seamless pipe, so it is used more.