Advanced technology workmanship and durable material - Made from tungsten steel and heat treated, the blade features high precision, smooth cutting operation, good impact resistance and good toughness . High quality - low incision resistance, improve opening speed, chip easy and no shaking. The perforation is neat, smooth, no broken edge. 16pcs include 16 different boring diameters: 15mm/16mm/17mm/18mm/19mm/20mm/21mm/22mm/23mm/24mm/25mm/26mm/ 28mm / 30mm / 32mm / 35mm. Wide range of applications - All wood and wood products, plastic, plywood and other materials that are essential for punching, suitable for industrial hinge installation, wood transformation and maintenance, model making, installation of spherical doors, drawers and more. Designed for durability and long life, creates a smooth, fine finish. Forstner Drill Bit - Providing handheld and portable woodworking drill, used for mounting ball point of door drawer, drawer; perforation on wood, plastic, wood, plywood, etc. Specifications: Material: cemented carbide Size: 15 mm (19/32 in), 16 mm (17/8 in), 17 mm (43/64 in), 18 mm (45/64 in), 19 mm (3/4 in ), 20 mm (25/32 in), 21 mm (53/64 in) , 22 mm (55/64 in), 23 mm (29/32 in), 24 mm (15/16 in), 25 mm ( 1 in), 26mm (1-1/16in), 28mm (1-1/8in), 30mm (1-3in) / 16in), 32mm (1-1/4in), 35mm (1 -3/8in)Quantity: 16pcsWeight: 750g Package Included: 16 x Drill Bits Important Note: When using this drill bit, the temperature of materials (e.g. wood, plastic products, plywood, etc.) becomes very high. Add water or coolant to prevent the material from emitting smoke.