According to the cross-sectional shape, there are round tubes, square tubes, rectangular tubes and special-shaped tubes.
According to materials, there are carbon structural steel pipes, low alloy structural steel pipes, alloy steel pipes and composite steel pipes.
According to the purpose, there are steel pipes for transportation pipelines, industrial structures, thermal equipment, petrochemical industry, machinery manufacturing, high-voltage equipment and so on.
According to the production process, there are seamless steel pipes and welded steel pipes. Seamless steel pipes are divided into hot rolled steel pipes and cold rolled steel pipes, and welded steel pipes are divided into straight welded steel pipes and spiral welded steel pipes.
According to the connection mode of pipe ends, there are smooth pipes and turning pipes.
According to the coating on the outside of steel pipes, there are black pipes and coated steel pipes.
Stacked seamless steel pipes, as shown in the figure.