First, the thicker the wall thickness of the product, the more economical and practical it is, and the thinner the wall thickness, its processing cost will increase significantly; second, the process of the product determines its limited performance, generally The precision of seamless steel pipe is low: the wall thickness is uneven, the brightness of the inner and outer surfaces of the pipe is low, the cost of cutting to length is high, and there are pits and black spots on the inner and outer surfaces that are not easy to remove; third, its detection and shaping must be processed offline. Therefore, it embodies its superiority in terms of high pressure, high strength, and mechanical structural materials.

Seamless pipe according to GB/T8162-87

4.1. Specifications: The outer diameter of the hot-rolled tube is 32-630mm. Wall thickness 2.5 ~ 75mm. Cold-rolled (cold-drawn) tube outer diameter 5 ~ 200mm. Wall thickness 2.5 ~ 12mm.

4.2. Appearance quality: There must be no cracks, folds, rolling folds, delamination, hairlines and scarring defects on the inner and outer surfaces of steel pipes. These defects should be completely removed, and the wall thickness and outer diameter must not exceed the negative deviation after removal.

4.3. Both ends of the steel pipe should be cut at right angles, and the burrs should be removed. Steel pipes with a wall thickness greater than 20mm are allowed to be cut by gas cutting and hot sawing. It is not necessary to cut the head after the agreement between the supply and demand parties.

4.4. Refer to GB3639-83 for "Surface Quality" of cold-drawn or cold-rolled precision seamless steel pipes.