Captive Screws are a specialist fastener that is retained within a target assembly or housing, typically with an unthreaded portion below the head, called a reduced shank. The screw is captive meaning it can not be totally removed from the hole or fall out when items are disassembled.
Captive screws are unique, however, because of their ability to be fastened and unfastened without removing the screw from the pilot hole in which it was installed. With a traditional screw, unfastening will result in the screw detaching from the pilot hole.
As Captive Fasteners offer a permanent fixing that cannot be simply lost or come loose and fall out, applications can benefit from a reduced risk of issues such as machinery downtime, general maintenance and needing to frequently replace components.
Captive screws can still be removed from their installation, but only intentionally - they are very unlikely to fall out accidentally once installed because the smooth shoulder of the captive screw remains in the panel unless specifically unscrewed.
