Abstract: A combination of a cup shaped or cylindrically shaped grinding wheel and a mounting means for such a wheel.

Abstract: A two zoned grinding wheel is disclosed having a lower section or zone composed of bonded abrasive grain and an upper zone or section made up of bonded particles of a material that is softer than the abrasive grain and therefore less abrasive. The wheel is especially suitable for being held in clamps or a chuck when being used, with the clamps or chuck contacting the wheel on the upper less abrasive section thus greatly reducing wear on said clamp or chuck.

Abstract: A grinding device is disclosed which is particularly suited for grinding railroad tracks. The device is made up of back plate attached to a grinding wheel which is in turn attached to a grinding machine by way of a spindle. The surface of the plate which makes contact with the grinding wheel contains at least two lugs and at least two bolt holes pass through the plate. The lugs on the plate mate with correspondingly shaped depressions or indentations in the side surface of the wheel which contacts the plate and threaded nuts molded in the wheel line up with the bolt holes in the plates and bolts passed therethrough keep the two parts together.