15 16 x 12 High Speed Long Boy (1 2" Shank) Phillips Wafer Cement Board Screws 3 32 x 12 High Speed 3 32 x 12 High Speed Aircraft Bit Cobalt Precision ground for high degree of concentricity between shank and body diameter 15 16 x 12 High Speed Long Boy (1 2" Shank) 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