1/4 Turn Fastener ComponentsThe perfect solution for mounting sheet metal and fiberglass body panels. Panel fasteners have been used in offroad racing for years due to their lightweight and durable design. Available in a variety of lengths to fit the thickness of your panels.
Originally quarter turn fasteners came from the Military Aerospace industry. When they say #5 they're referring to the diameter of the button which is 5/16". Or if they say #6 they are referring to the diameter of the button which is 3/8" (0.408" actual). The length of the button is measured from the panel surface down to the bottom edge of the spring seat. See below picture for reference.