Hanger bolt style breadboard screw. This screw is used to attach a knob to the front of a door or surface without having to drill a hole ,or even to have access to the inside of the door, drawer or surface. Hence the common name "breadboard" screw-- it was used to screw a knob into the front edge of a board that slides in and out under a countertop on a Hoosier hutch or other kitchen cabinet --- a board to "knead" bread on. Simply thread the 8-32 threaded end into your favorite cabinet knob, and screw the wood screw end into anything you want a knob on(within reason, of course). Overall: 5/8" long Knob Thread: 8-32 x 1/4" Wood Screw: 3/8"