Precision Drilling: Precision drill pilot holes in hinges, handles, drawer slides and other hardware, to ensure screws are straight and flush for proper hardware installation. Sharp: 135 degree oblique edge the head of a bit, make the drill bit drill faster in the position of the hinge holes Wood chips are automatically discharged: The sawdust will be automatically drained from both sides of the holes, without a drill blocked, you do not have to remove wood chips, effectively increasing your work Combine with the punch: The automatic punch is more convenient because it does not require a hammer, it prevents the bits from wandering on the smooth surfaces, perfect for repetitive punches or rivets, adjustable for light or heavy hits, perfect for any DIYer. These self-centering bits are perfect for drilling perfectly centered holes in hinges, hardware or whenever you need precisely placed holes. The beveled ends of the edges keep them centered even if the hole is slightly smaller than standard door hardware. They have drill depth adjustments and recessed hex shafts for quick connectors.