Captive Screws

Captive screws lock into position and allow for easy assembly. The main feature of captive screws is that they remain attached to a panel or parent surface, even after removal of the attached piece. They cold-form with the parent material and part into a single entity. They are sometimes used with split washers that clip on once the captive screw is inserted into a panel. Threaded panel holes can also be used. Captive screws are not interchangeable with each other but come in a vast range of sizes and material types. Captive screws also have a wide number of head types. Some, such as binding, button and fillister heads, have rounded or convex tops, but most types of captive screws have flat bearing surfaces. Some captive screws, such as a five-sided head, require special wrenches to tighten or loosen them and are designed for specialized applications. Square and hexagonal head captive screws also require a wrench. Captive screws have a wide number of applications. High-volume production lines, from furniture to computer casing, are some examples. Captive screws are also seen in domestic items, such as flat pack furniture. Specialized applications for captive screws include fire hydrants.