Point anchoring rock bolt Diameter :16 18 20 22 ... or rib thread bolt,slot and wedge Point anchoring rock bolt Point anchoring rock boltis composed of screw thread ... nut ,yield tube, washer , and other accessories . According to the structure of steel bar ,the bolt has two stypes ... coal seam ,that has high stress, large deformation, difficult to support and other poor environment .Feature :(1) The bolts ...