1. Drill bush for precise positioning, will not move.High speed steel body designed, durable and excellent for use. 2. Sawdust will be automatically discharged from the top of the holes on both sides, without drill blocked. 3. Popular sizes used for carpenters, cabinet, furniture makers and other wood working trades.Various specifications to meet the needs. 4. It is a set of professional drilling tools, applicable to the installation of the door hinge. 5. Packing list: 7*Center drill bit Type & Dimension: 5/64: Hole diameter is about 2mm, use about 2.2-2.8mm tapping screw. 7/64: Hole diameter is about 2.8mm, use about 3-3.5mm tapping screw. 9/64: Hole diameter is about 3.5mm, use about 4-4.5mm tapping screw. 11/64: Hole diameter is about 4.5mm, use about 5-5.5mm tapping screw. 5mm: Hole diameter is about 5mm, use about 5.5-6mm tapping screw. 13/64: Hole diameter is about 5.1mm, use about 5.6-6.1mm tapping screw. 1/4: Hole diameter is about 6.3mm, use about 6.8-7.3mm tapping screw. Specification: General Material Brass, Steel Package Weight One Package Weight 0.22kgs / 0.49lb One Package Size 20cm * 10cm * 5cm / 7.87inch * 3.94inch * 1.97inch Qty per Carton 40 Carton Weight 9.76kgs / 21.52lb Carton Size 52cm * 42cm * 22cm / 20.47inch * 16.54inch * 8.66inch Loading Container 20GP: 555 cartons * 40 pcs = 22200 pcs 40HQ: 1288 cartons * 40 pcs = 51520 pcs