Expansion grommets are types of PCB (printed circuit board) spacers used to secure PCBs or panels.
Expansion grommets are used to securely fasten and space panels or components in many industries. They are found in domestic appliances, motor vehicles and electrical circuit boards.
There are several types of expansion grommets suitable for various applications. Front mounted standard screw grommets, for example, provide increased bearing area and added thread engagement. The non-conductive parts fully cover up the metal screws, providing electrical insulation, as well as protection against moisture, temperature transfer and exposed screw points.
Round hole screw grommets are used in applications with a punched or drilled hole. A pin in the grommet expands the grommet's prongs as it's driven into the hole. This provides friction between the inside of the hole and the grommet, locking it securely in place and preventing the screw from rotating in the hole.