precision drilling:Accurately drill pilot holes in hinges, handles, drawer slides, and other hardware, to 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 are automatically discharged:Sawdust will be automatically drained from both sides of the holes, without drill blocked,you 't have to remove wood , effectively increasing your work Combinate with punch: Automatic punch is more convenient as they 't require a hammer,stop drill from wandering on plain surfaces,great for repetitive punching or riveting,adjustable for light or heavy strokes,perfect for DIY users tool kit. These Centering are great for drilling perfectly centered holes in hinges, hardware, or any time that you need accurately placed holes. The beveled edge tips keeps 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 Centering Drill+punch Description: 1. Material:HSS 2. Color: Sliver 3. They come with HSS drill that are replaceable with jobber 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. centering for consistently 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 - 5.5 mm tapping screw Note: Please appropriate adjustments according to the hardness of wood when opening, if wooden ,you can a smaller size, if hard wood, corresponding or a bigger size. Package include: 4 pcs HSS Centering Hinge Drill Set Door Cabinet 1 pcs Gold Hole Punch Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.