These self centering bits are great for drilling perfectly holes in hinges, hardware, or any time that you need accurately placed holes. Unique design and for DIY person and professionalist. Great for drilling perfectly holes in hinges, hardware, or any time that you need accurately placed holes. Features - Colour: As shown. - Material: aluminum - Size: 12 x 8.5 x 1.5cm - Hinge screw size: 5/64’’, 7/64’’,9/64’’,11/64’’, 5", 13/64", 1/4" - Unique design and for DIY person and professionalist. - Positioning accuracy withnot shift. It can discharge automaticly that the chips fall from the of the drill hole and go out from either side of it. The Drill bits won’t be stucked. - Great for drilling perfectly holes in hinges, hardware, or any time that you need accurately placed holes. Specifictions - The 5/64", placed hole diameter is about 2 mm, is great suitable for 2.2-2.8 mm tapping screw - The 7/64", placed hole diameter is about 2.8 mm, is great suitable for 3-3.5mm tapping screw - The 9/64", placed hole diameter is about 3.5 mm, is great suitable for 4-4.5 mm tapping screw - The 11/64", placed hole diameter is about 4.5 mm, is great suitable for 5-5.5 mm tapping screw - The 5", placed hole diameter is about 5 mm, is great suitable for 5.5-6 mm tapping screw - The 13/64", placed hole diameter is about 5.1 mm, is great suitable for 5.6-6.1 mm tapping screw - The 1/4", placed hole diameter is about 6.3 mm, is great suitable for 6.8-7.3 mm tapping screw Package list: 7 x Hinge Drill Bit