ITEM NAME:4pcs Self Centering Hinge Drill Bits Set,1/4inch Hex Shank, screw sizes 5/6 B5Q8 4pcs Self Centering Hinge Drill Bits Set,1/4inch Hex Shank, screw sizes 5/6 B5Q8 precision drilling:Accurately drill pilot holes in hinges, handles, drawer slides, and other hardware, to ensure the screws are straight and flush for proper hardware installation. Sharp: 135 degree oblique edge the head of a bit,make the drill more rapid drilled into the position of hinge holes Wood chips are automatically discharged:Sawdust will be automatically drained from both sides of the holes, without drill blocked,you don't have to remove wood chips , effectively increasing your work Combinate with punch: Automatic center punch is more convenient as they don't require a hammer,stop drill bits from wandering on plain surfaces,great for repetitive punching or riveting,adjustable for light or heavy strokes,perfect for every DIY users tool kit. These Self Centering Bits are great for drilling perfectly centered holes in hinges, hardware, or any time that you need accurately placed holes. The beveled edge tips keeps them centered even if the hole is slightly smaller than standard home door hardware. They have drill bit depth adjustments and recessed hex shafts for quick connectors. Pattern Name:4pcs Self Centering Drill+punch Description: 1. Material:HSS 2. Color: Sliver 3. They come with HSS drill bits that are replaceable with jobber bits if ever needed. 4. They come in the hinge screw sizes 5/64, 7/64, 9/64, 11/64 inch 5. Spring loaded outer guide keeps the high-speed drill centered 6. Fit for drilling pilot holes in cabinet and door hinges and door butts 7. Self centering for consistently accurate pilot holes Size: 5/64 inch: Hole diameter is about 2 mm,Use about 2.2 - 2.8 mm tapping screw 7/64 inch: Hole diameter is about 2.8 mm,Use about 3 - 3.5 mm tapping screw 9/64 inch: Hole diameter is about 3.5mm,Use about 4 - 4.5 mm tapping screw 11/64inch: Hole diameter is about 4.5mm,Use about 5