Do Captive Panel Screws Really Not Fall Off?

There are thousands of kinds of screws, usually used hexagon cylindrical head screws, outer hexagon screws, pan head screws, flat head screws,etc.,But when these screws will be loosen, they will fall off. However some scenes are required to screw can be connected to the body, after loosening the screw, the screw will not fall down. In order to prevent the screw from falling off, solve the problem of small screw falling off is not easy to find or avoid the adverse consequences caused by falling off, then people worked out how to produce the captive panel screws!

As the name implies, the screw doesn't fall down on its own. So why don't you pull out the screw and not fall out? We will talk about what the principle is. Captive Screws by adding a section of rob without thread whose diameter is smaller than the thread diameter, rely on the small rob without thread to hang the screw on the connector (or through the sleeve, circlip spring), to prevent the screw from falling off.

The captive screw structure itself does not have the function of preventing falling off, the screw function is to be realized by the connection between the connecting parts, through some structure of the screw small rob without thread stuck in the connecting parts of the mounting hole to prevent falling off, so the captive panel screw can be loosened but not dropped.