Door rack bolts are an ideal way to increase security on timber doors. They are morticed into the door and operated by a spline key that throws the bolt into the frame. For optimum security it is recommended that the bolts are fitted to the top and the bottom of the door. Extra security. 60mm length. Used with spline key. Fixings included. Bolt Throw mm: 18. Material: Steel. Finish: Electro Brass.