Seamless steel pipes or welded steel pipes with a ratio of outer diameter to wall thickness of less than 20 are called thick-walled steel pipes. It is mainly used as octg pipe, petroleum geological drilling pipe, cracking pipe for petrochemical industry, boiler pipe, bearing pipe, high-precision structural pipe for automobile, tractor and aviation, etc.

The thick-walled square tube is a hollow square cross-section light-duty thick-walled steel tube, also known as steel cold-formed profile. It is a section steel with a square cross-section shape and size made of Q235 hot-rolled or cold-rolled strip or coil as the base material, which is cold-bent and then high-frequency welded. In addition to the thickened wall thickness of the hot-rolled extra-thick-walled square tube, its corner size and edge straightness have reached or even exceeded the level of the resistance-welded cold-formed square tube.

The connection method between the seamless pipe for transporting gas, pipe joints, valves and inlet and outlet pipes on equipment. It is determined by factors such as the nature, pressure and temperature of the gas, the material, size and installation place of the pipe. There are four main methods: threaded connection, flange connection, socket connection and welding.

​​​​​​​Alloy pipe is a kind of seamless steel pipe, and its performance is much higher than that of ordinary seamless steel pipe. Because this kind of steel pipe contains more Cr, its high temperature resistance, low temperature resistance and corrosion resistance are not comparable to ordinary seamless steel pipes. Therefore, alloy tubes are widely used in petroleum, aerospace, chemical, electric power, boiler, military and other industries.

Sheet piles are steel profiles with interlocking edges. They are driven into the ground to provide excavation support. These sheet piles are used to support walls, clear land, create underground structures, and river bank or coastal protection.

The bending degree of steel pipes (seamless pipes and welded steel pipes) refers to the maximum degree of bending that the steel pipes can withstand during the bending process. This parameter is very important for the use of steel pipes, because it directly affects the service life and safety performance of steel pipes.