There are many products and specifications of seamless steel tubes, and their performance requirements are different. All of these should be distinguished by changes in user requirements or working conditions. Generally, SMLS pipe products are classified according to section shape, production method, pipe, connection, electroplating characteristics and use.


The cross-section shapes of SMLS pipes can be divided into circular steel pipes and special-shaped steel pipes.


Special-shaped steel pipe is a kind of non-circular section steel pipe. Among them: square tube, rectangular tube, elliptical tube, flat tube, semicircular tube, hexagonal tube, hexagonal inner tube, unilateral hexagonal tube, equilateral triangular tube, pentagonal flower tube, octagonal tube, convex tube, double convex tube. Double tube, multi-concave tube, melon tube, flat tube, diamond tube, star tube, parallelogram tube, ribbed tube, dropper, inner fin tube, twist tube, tube and multi-layer tube.


The longitudinal section shape of SMLS pipe can be divided into section steel and section steel pipe.


SMLS pipe refers to the length, inner and outer diameter and wall thickness of the pipe along the cross-section shape, such as the periodic or non-periodic changes of the pipe. Its main parts are: conical tube, conical tube, trapezoidal tube, trapezoidal tube, circular cross-section tube, bellows, heat dissipation pipe and double tube belt.