15/32 x 12 High Speed Long Boy . Straight shank to 1/2” 1/2” reduced shank for sizes above 1/2” M2 high speed steel Sharp cutting edge to drill in many different materials: Mild Steel Cast Iron Aluminum Wood Extra length flute with continuous cutting edges for drilling deep holes and fast chip removal Reduced shank fits all drill motors with 1/2” chucks Non-slip grip prevents the bit from spinning in the chuck