Captive Panel Screws are designed to remain attached even if unscrewed when used with a captive panel retainer. Most commonly used on control panel doors to keep the door screwed shut during normal operating conditions. When access is needed, unthreading the screw allows for the door to be open, while the retainer keeps the screw attached to the door. Perfect for applications where a lost screw poses safety or cost concerns. All Lyn-Tron Captive Panel Screws come in multiple head designs, varying shank lengths and diameters, and all common thread sizes. With so many options, you are sure to find the right screw for your application.