These tools are used to properly set the tubular style rivets that are used throughout the the Model A. 1/8" was used for attaching the crank hole cover in the radiator shell and the socket in the 30-31 cowl lamps, 9/64" was used for brake linings, hood bumpers, hood clips, and hood handles. 3/16" was used for windshield swing arm brackets, closed car door latches, floorboard irons, shift lever plate retainers, and transmission forks. U.S.A.