Aircraft inspection plates, doors, and other removable panels are secured with turnlock fasteners because they allow quick and easy removal of panels for inspection and servicing. These fasteners require positive sustained torque to unfasten and tend to correct themselves after minor disturbances. The most common manufactured
are Dzus, Camloc, and Airloc. Some of the common names used to refer to turnlock fasteners are quick opening, quick action, and stressed panel fasteners
Dzus turnlock fasteners
have a stud, grommet, and receptacle. The stud is made from steel and are cadmium plated. There are three head styles: wing, flush, and oval. Turning the stud clockwise locks the fastener and turning it counterclockwise unlocks it. This is done using a specialized tool. The force that locks the stud in place is created by the spring.
Some of the most commonly used Camloc fasteners
are the 2600, 2700, 40S51, 4002, and the stressed panel fasteners. Camloc fasteners are used on aircraft cowlings and fairings. The fastener has a stud assembly, a grommet, and a receptacle. Receptacles are sorted into two categories: rigid type and floating type. The receptacle is fastened to the aircrafts structure and the stud and grommet are installed in the removable portion while the stud and grommet are installed in a plain, dimpled, countersunk, or counterbored hole.
Anchor Panel fasteners
have a stud, a cross pin, and a stud receptacle. There are flush, oval, and wing studs. It is important to know the thickness of the material being secured, as it has to be determined in order to choose a stud of the correct length. The cross pin is made from chrome-vanadium steel that has been heat treated. They provide the greatest strength, wear, and holding power. Once a cross pin is removed from the stud, a new one must replace it.