Thick-walled seamless steel pipe: The manufacturing process can be divided into four basic methods: cold drawn, cold rolled, hot rolled, and thermally expanded. The material of the steel pipe is 10#, 20#, 35#, 45# and is called ordinary steel pipe. Divided into seamless steel pipes for structure; seamless steel pipes for transportation; seamless steel pipes for boilers; high-pressure seamless steel pipes for boilers; high-pressure seamless steel pipes for fertilizer equipment; seamless steel pipes for geological brick exploration; seamless steel pipes for petroleum brick exploration ; Seamless steel pipes for petroleum cracking; seamless steel pipes for ships; cold-drawn cold-rolled precision seamless steel pipes; various alloy pipes. Seamless steel pipes are represented by outer diameter and wall thickness. Thick-walled seamless steel pipes are mainly used for mechanical processing, coal mines, hydraulic steel and other purposes.