The HI-LITE™ fastener is similar in design and principle to the HI-LOK™ fastener, has the controlled radius from full diameter section to the threaded area of the HI-TIGUE™ fastener, and has a shorter transition area between the shank and the first load-bearing thread. HI-LITE™ fasteners have approximately one less thread. These differences reduce the weight of the HI-LITE™ fastener without lessening the shear strength. HI-LITE™ fasteners are available in the same materials and head configurations as the HI-LOK™ system, and can also be installed in high interference like the HI-TIGUE™ fastener. HI-LITE™ collars are also different and thus are not interchangeable with HI-LOK™ collars or HI-TIGUE™ collars.

Captive fasteners are used for quick removal of engine nacelles, inspection panels, and areas where fast and easy access is important. A captive fastener can turn in the body in which it is mounted, but will not drop out when it is unscrewed from the part it is holding. Some of the most commonly used are the Dzus, Camloc, and Airloc.

Turn lock fasteners are used to secure inspection plates, doors, and other removable panels on aircraft. Turn lock fasteners are these fasteners is that they permit quick and easy removal of access panels for inspection and servicing purposes. Turn lock fasteners are manufactured and supplied by several manufacturers under various trade names.

The Dzus turn lock fastener consists of a stud, grommet, and receptacle. Figure 7-58 illustrates an installed Dzus fastener and the various parts.

The grommet is made of aluminum or aluminum alloy material. It acts as a holding device for the stud. Grommets can be fabricated from 1100 aluminum tubing, if none are available from normal sources.

The spring is made of steel, which is cadmium plated to prevent corrosion. The spring supplies the force that locks or secures the stud in place when two assemblies are joined.

The studs are fabricated from steel and are cadmium plated. They are available in three head styles: wing, flush, and oval. Body diameter, length, and head type may be identified or determined by the markings found on the head of the stud. [Figure 7-59] The diameter is always measured in sixteenths of an inch. Stud length is measured in hundredths of an inch and is the distance from the head of the stud to the bottom of the spring hole.

A quarter of a turn of the stud (clockwise) locks the fastener. The fastener may be unlocked only by turning the stud counterclockwise. A Dzus key or a specially ground screwdriver locks or unlocks the fastener.

Camloc fasteners are made in a variety of styles and designs. Included among the most commonly used are the 2600, 2700, 40S51, and 4002 series in the regular line, and the stressed panel fastener in the heavy-duty line. The latter is used in stressed panels, which carry structural loads.

The Camloc fastener is used to secure aircraft cowlings and and floating. [Figure 7-60]

The stud and grommet are installed in the removable portion; the receptacle is riveted to the structure of the aircraft. The stud and grommet are installed in either a plain, dimpled, countersunk, or counter bored hole, depending upon the location and thickness of the material involved.

A quarter turn (clockwise) of the stud locks the fastener. The fastener can be unlocked only by turning the stud counterclockwise.