Abstract: A mining roof bolt structure includes an elongate bolt having a head and a threaded shank, a cylindrical sleeve made of a compressible and expandible material disposed about a substantial portion of the length of the shank, a cap nut having a diameter greater than the diameter of the sleeve when the sleeve is not compressed, for engaging the walls of a hole into which the roof bolt is inserted, with the cap nut being screwable onto the threaded shank to contact one end of the sleeve, and a holding plate disposed on the shank of the bolt between the sleeve and the bolt head so that the plane of the plate is generally perpendicular to the shank of the bolt. As the bolt is tightened on the cap nut in the hole, the sleeve is compressed longitudinally to thereby cause it to expand radially and contact the side walls of the hole. This secures the roof bolt structure in place to provide support for the roof or wall in which the hole is located.