Specifications‎:‎Four piece set includes bits for drilling pilot holes for screw sizes #6‎,‎#8‎,‎#10 and #12‎.‎Special designed steel counter sleeve countersinks or counter bores pilot hole‎.‎Adjustable counter sleeve depth with allen wrench‎.‎Standard hex shank is quick change compatible‎.‎Drill and countersink for wood screws without changing bits‎.‎Drilling length can be adjusted for various length screws simply by loosening and tightening the setscrew‎.‎Type‎:‎ Drill Bit SetColor‎:‎ BlackQuantity‎:‎ 4 PcsMaterial‎:‎ HSS Drill 4241Black Chamfer Drill Body Material‎:‎ Steel #45Usage‎:‎ for Carbon Steel‎,‎ Thin Iron Plate‎,‎ Insulating Plate‎,‎ PVC Board‎,‎ Wood6# Size‎:‎ 2.38mm/0.09‎"‎ ‎(‎Approx‎.‎‎)‎8# Size‎:‎ 2.78mm/0.11‎"‎ ‎(‎Approx‎.‎‎)‎10# Size‎:‎ 3.175mm/0.12‎"‎ ‎(‎Approx‎.‎‎)‎12# Size‎:‎ 3.56mm/0.14‎"‎ ‎(‎Approx‎.‎‎)‎Hex Shank Diameter‎:‎ 6.35mm/0.25‎"‎ ‎(‎Approx‎.‎‎)‎Notes‎:‎Due to the light and screen setting difference‎,‎ the item‎'‎s color may be slightly different from the pictures‎.‎Please allow slight dimension difference due to different manual measurement‎.‎