1, according to the production method can be divided into two categories: seamless steel pipe and seamed steel pipe, seamed steel pipe referred to as straight seam steel pipe.
2, the steel pipe according to the pipe material (i.e., steel) can be divided into: carbon pipe and alloy pipe, stainless steel pipe, etc..
3, the steel pipe can be divided into according to the end of the pipe connection: light pipe (pipe end without thread) and car silk pipe (pipe end with thread).
4, according to the surface coating characteristics of steel pipe can be divided into: black pipe (not coated) and coated pipe.
5, steel pipe can be divided into: round steel pipe and shaped steel pipe according to the shape of the cross-section.
Expanded Information:
The specification requirements of spiral steel pipe shall be set out in the import and export trade contract. Generally should include the standard brand (type code), the nominal diameter of steel, nominal weight (quality), the length and tolerance values of the above indicators.
China's standard recommended nominal diameter of 8, 10, 12, 16, 20, 40mm spiral steel pipe series. The supply length is divided into two kinds of fixed feet and times the feet. China's exports of rebar sizing options range from 6 to 12m, Japanese rebar sizing options range from 3.5 to 10m.
Two, the appearance of quality
1, surface quality.
The surface quality of rebar is stipulated in the relevant standards, which requires that the end should be cut straight, the surface should not have cracks, scars and folding, and there should be no defects that are harmful to the use of rebar.
2, external dimensions deviation allowance.
The curvature of the rebar and the requirements of the geometry of the steel bar in the relevant standards. For example, China's standards provide that the curvature of straight bars is not greater than 6mm/m, and the total curvature is not greater than 0.6% of the total length of the bar.
Baidu Encyclopedia-Steel Pipe