The countersink mounted on the attachment holder efficiently drills, countersinks, and deburrs in wood in one step. When mounted on a wood twist drill, all three applications can be performed simultaneously with professional results. The countersink is suitable for both hard and soft wood, for laminated and non-laminated particle board, as well as for plywood. This multifunctional drill made of tool steel has a countersink angle of 90 degrees, five cutting edges, and can also be used as a depth stop. It includes a hex key. The wood twist drill is not included.