Friction bolt is the most basic part of roadway support in contemporary coal mines, it reinforced the surrounding rock of the roadway, make the surrounding rock support itself. The bolt is not only used in mine, but also used in engineering technology. Specification: 18*2m, 16*6m (customize according to customer requirement) Material: 16Mn, 20Mnsi We can supply the friction bolt with high quality and competitive price, if you are intrested in our products plaese visit our website