Seamless steel pipes are perforated from a whole round steel, and
steel pipes without
welds on the surface are called seamless steel pipes. According to
the production method, seamless steel pipes can be divided into
hot-rolled seamless steel pipes, cold-rolled seamless steel pipes,
cold-drawn seamless steel pipes, extruded seamless steel pipes, and
top pipes. According to the cross-sectional shape, seamless steel
pipes are divided into two types: round and special-shaped.
Special-shaped pipes have square, oval, triangular, hexagonal,
melon seed, star, and finned pipes. The maximum diameter is 900mm
and the minimum diameter is 4mm. According to different uses, there
are thick-walled seamless steel pipes and thin-walled seamless
steel pipes. Seamless steel pipes are mainly used as petroleum
geological drilling pipes, petrochemical cracking pipes, boiler
pipes, bearing pipes, and high-precision structural steel pipes for
automobiles, tractors, and aviation.