General hardware screws. #2, #4, #6 Second from bottom is an Atlas track screw. Weaver trucks used a #2 machine screw, though often the screws, 3/4" to 1" in length were too short. Slightly longer 1 1/4" were too long, would push through the bottom of a coal hopper. #6 Screws top, #4 screws middle, #2 screws bottom