These spindles allow you to convert your bench grinder into a polishing machine by bringing the mop out away from the machine and providing a taper thread for you to attach a mop. Fits virtually all 8" bench grinders (fits 5/8" shaft). Fixes via a grub screw (we do not use threaded spindles because you rely on the accuracy of the thread on the grinder which often leads to a wobbly non centred shaft). Total length of spindle 6"