Big Horns Countersink Counter bore Wood Drill Bit Kit pre-drills holes and countersinks even hardwood and aluminum, thereby reducing the risk of splitting the panel, and giving every screw nail or bolt a nice appearance as it appears flush with the furnitures surface, and can be covered nicely with wooden plugs.Great for hinge, Stair book case, coffee table, chair, cabinet, closet, wall, desk, bed, kitchen, bedroom, office, studio, dresser, bench. Countersink may also be used to remove burr left from a drilling/tapping operation thereby improving the finish of the project removing any hazardous sharp edges.Both the Countersink bits the collars have hex nuts for easy adjusting tightening accurate positioning. Kit comes with the Correct Allen Wrench for tightening the nuts.Features:Cuts and clears chips quicker and leaves a smooth countersink. Drill, countersink, and counter bore holes in one easy step. Ideal to use with quick change chucks. Adjustable counter sleeve depth gives you total freedom to adjust as you need based on each projectBits are made from hardened high speed steel to endure and last through any job you can throw at it. Bits have sharp tips and are able to sustain heat and pressure without breakingDrill Bits are precisely machined to get you the exact hole size in countersinking and counter boring. Each Drill bit is properly labeled and gives you the exact sizing of the hole you are creating.Applications:Works with all types of wood/lumber: Plywood, Pine, Oak, Birch, Mahogany, Maple, Cedar, Fir, Cherry, Poplar, Alder, Ash, Walnut, Hemlock.Unit of MeasureSet of 7 pcs