#40 Pilot x 3/8" 100 Deg HSS 1/4-28 Threaded Shank Stop Countersink 3660220 which means it can be

which means it can be converted to internal balance

including 6 extra-deep pockets for long screwdrivers

2-3/4" (75mm)

This is for for 1 x 13A0765 Mitsuba Fan Belt

Tooline 40mm Chuck Guard

#40 Pilot x 3/8" 100 Deg HSS 1/4-28 Threaded Shank Stop Countersink 3660220 which means it can beCountersink cutters may be used in all popular adjustable or micro stop countersinking units utilizing a threaded shank drive. Made from the finest high speed tool steel. Precision ground to exacting tolerances and form relieved to insure concentricity of countersink angle Pilot diameter; #40 Body diameter: 3 8" Shank thread: 1 4 28 Included angle: 100 degrees