Captive fasteners use the swage (flat collar Figure 1) or flared (100º or 82º countersink Figure 2) method of upsetting the sleeve to captivate the assembly to the panel.
There are three types of holes suitable for captive fastener installation:
Type one: Through-hole
This type of hole is suitable where there is a gap or gasket between the top and bottom panels or when flush mating of the panels is not required.
Type two: Counterbore hole
Counterbore holes maximize holding power and provide flush mating between the top and bottom panels.
Type three: Countersink hole
Countersink holes are suitable where panel thickness permits. They provide flush mating between the bottom and top panels.
Note: See the engineering standards for recommended hole diameters, counterbore/countersink depth and installation tools.