FRACTIONAL, SELF-STARTING TYPE; HIGH SPEED STEEL MATERIAL; 3/16 INCH MIN. DRILL SIZE; 7/8 INCH MAX. DRILL SIZE; HEX SHANK TYPE; 3/8 INCH SHANK SIZE; 12 SIZE(S); 1/16 INCH STEP INCREMENT; NOMINAL SIZE #4; MAXIMUM MATERIAL THICKNESS 1/8 INCH