Seamless steel pipes have a wide range of applications. Seamless steel pipes for general use are rolled from ordinary carbon structural steel, low-alloy structural steel, or alloy structural steel, with high production and mainly used as pipelines or structural parts for transporting fluids. 2. They are supplied in three categories according to different uses: a. They are supplied according to their chemical composition and mechanical properties; b、 Supply based on mechanical performance; c、 Supply according to hydraulic pressure test. Steel pipes supplied according to categories A and B, if used to withstand liquid pressure, also need to undergo hydrostatic testing. 3. There are various types of seamless pipes for specialized purposes, including seamless pipes for boilers, seamless steel pipes for chemical and electrical industries, seamless steel pipes for geological applications, and seamless pipes for petroleum applications.