Diamond Countersink 3/8" X 1/4"-28; 100 deg., .1405" (#28) integrated pilot; 40/50-diamond

Diamond Countersink 3/8" X 1/4"-28; 100 degree with .1405" (#28) integrated pilot; 40/50 grit diamond. Ideal for use on carbon fiber, fiberglass, fiber reinforced plastics and other abrasive type materials