Specifications and appearance quality precision steel plant in Shandong http: //www.sdlggg.com
Seamless pressing GB / T8162-87 provisions 4.1 specification : Hot tube diameter 32 ~ 630mm wall thickness of 2.5 ~ 75mm cold-rolled ( cold drawn ) tube diameter 5 ~ 200mm wall thickness of 2.5 ~ 12mm 4.2,.... appearance quality : internal and external surfaces of the steel pipe must not have cracks, folding, rolling off, separation, hairline and scarring defects these defects should be completely removed, the outer diameter of the wall and not a negative bias after clearing more than 4.3 steel. the ends should be cut at right angles, and clear the glitch. pipe wall thickness greater than 20mm allows hot gas cutting and sawing. by agreement between or may not be truncated. 4.4, drawn or cold rolled precision seamless steel tubes ( surface quality ) reference GB3639-83.