These self centering drill bits put hinges right where they should be in the center.4 of the most often used sizes for carpenters, cabinet, furniture makers and other wood working trades.Easy e and install.Positioning accuracy, will not shift, the chips will automatic discharge from the hole on either side of the top of the drill, not stuck drill.SpecificationsMaterial: Brass + HSSColor: SilverSize:5/64inch: Hole diameter is about 2mm, Use about 2.2 - 2.8mm tapping screw7/64inch: Hole diameter is about 2.8mm, Use about 3 - 3.5mm tapping screw9/64inch: Hole diameter is about 3.5mm, Use about 4 - 4.5mm tapping screw11/64inch: Hole diameter is about 4.5mm, Use about 5 - 5.5mm tapping screwPackage Contents:1 x 4Pcs HSS Self Centering Hinge Drill Bit SetOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.