A concealed hinge drilling jig is a type of support jig, designed for drilling 3 cm holes to fit concealed hinges into modern wardrobe doors. As many of the complementary tools used in woodworking, it uses an electric hand-drill for its operation, making a Forstner bit to turn.For most concealed hinges to work properly, a pit hole must be created on the door at the point where it faces the static part of the hinge which is screwed to the inside wall of the wardrobe. To create the pit hole, the jig must be fixed in place by means of the provided clamp, spin the Forstner bit by applying an electric hand-drill to its axle. The hole is drilled by pressing the hand-drill until a satisfactory pit hole is created.The purpose of the drilling jig is to hold a Forstner bit in place, at a 90º angle while drilling 3 cm pit hole. The angle of the tool is critical for the performance of concealed hinges, the jig allows maintaining the 90º angle over a number of drilling sessions.