The panel fasteners covered by this specification are for use on aircraft, where a readily operated fastener is required, such as panels, inspection doors, and quick detachable plates which do not carry primary structural stresses.

Type I flush-head fasteners are intended for use on the external surfaces of aircraft. Type II and III fasteners are intended for interior use and where the fastener stud heads are not subject to airflow.

Styles 1 and 2, Type I, fasteners are suitable for use in the more ductile materials where dimpling for Styles 1 and 2 may be accomplished without heated dimpling equipment. They are also suitable for use in the harder materials where heated dimpling equipment must be used in forming the Type I dimples.

Style 3, Type I, fasteners are suitable for installation in aluminum alloys, magnesium alloys, and CRES without the use of heated dimpling equipment in forming the dimples for Type I fasteners.