STEELEX BRAND35 MM CARBIDE TIPPED BITFOR BORING HIDDEN HINGES NOT INTENDED FOR HAND DRILL USEOVERALL LEANGTH 2.5 "CUTTER DIAMETER 35 MMSHAFT DIAMETER 3/8 "HAS FLAT GROUND ON SHAFT FOR SET SCREWS HOLDERS SHAFT LENGTH 1 3/4" OVERALLSHAFT LEANGTH GROUND TO 3/8 " DIAMETER 1 3/16"THIS IS THE BIT TO HAVE FOR BORING HIDDEN HINGE HOLES IT HAS A SHALLOW POINT SO YOU DONT BORE THRU THE FACE OF THE DOOR.THESE BITS HAVE TWO EXTRA CARBIDE TIPS FOR A CLEAN SMOOTH CUTECCELENT FOR HARDWOODS!