DEVELOPMENT OF HI-PRECISION COLD-DRAWN STEEL TUBE FOR HYDRAULIC PILLAR

Introduced in the article are the general situation of domestic development of coal mine supporting/protecting equipment and tubular products used therefor. Also described are the main aspects of manufacture of hi-precision steel tubes for coal mine-used hydraulic pillar cylinder body and piston by means of the cold-drawing process, involving the technological process, relevant equipment and performances and quality of the tubes as well. Relevant site application of the said hi-precision steel tubes has proven that they are up to all the requirements to the performances of the hydraulic pillar and that there is a big potential market for the tubes.