-The 402 mandrel is used primarily with cut-off wheels but is used with the following Dremel accessories: 409, 411, 412, 413, 420, 423, 425, 426, 456, 511, 512, 540 and 541 -Used primarily with Dremel polishing bits and accessories -For use in all Dremel rotary tools 1/8 In. shank (User Tips) Insert the small screw through the hole in the cut-off wheel then tighten the screw into the mandrel's threaded head.