Plastic Screw Grommets & Lock Nuts
These simple automotive fixings are normally used for mounting trims and parts to metal bodywork. The grommet fits into the metal bodywork and allows a part or panel to be aligned then fastened using a screw or bolt. The grommet means that the screw doesn't have to pass directly into the metal bodywork and so often more flexibilty and better protection.
Also known as expansion nuts, lokuts, lock nuts, screw grommets and captive nuts.