These drill bits are made of cemented carbide,The drill head adopt arc curve design.The drill bit includes a center point which guides it throughout the cut and incidentally spoils the otherwise flat bottom of the hole.Cut the panel smoothly and not hairy holes.Sharp edge,high hardness,accurate positioning,high precision,smooth cutting,impact resistance,high toughness.Used for wood perforation,spherical door tip installation,drawer tip,plastic products,wood,plywood,etc.Trepanning more smooth,less noise.Color:silverMaterial:CarbideSize:Blade diameter 15mm 20mm 25mm 30mm 35mmPackage Contents:5pcs * Woodworking hole openerOnly 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.