Captive screws are designed to remain attached to a specific component (even when fully loosened) so they don’t get lost during assembly or maintenance. Also called captive panel screws, these specialized fasteners are commonly used in electrical panels, maintenance panels and other enclosures and covers - especially in applications where foreign object debris must be prevented, such as aerospace.
Like shoulder screws, captive screws have an unthreaded section below the head, but captive screws will stay in the pilot hole (even when unfastened) when used with a retaining washer.
Precision stainless steel captive screws from Berg are available with a knurled, slotted or hex socket head in thread sizes #4-40, 6-32, 8-32 and 10-32 (M3 x .5, M4 x .7 and M5 x .8 mm). Special sizes, materials or finishes available on request.