High quality zinc plated carbon steelM3 metric sized partPack of 100 rivet nutsFlat head with knurled round bodyRivet nuts can be installed in many different material types including steel, plastic and fiberglassA rivet nut, also known as a threaded insert or a blind rivet nut, is a mechanical fastener that, as the name suggests, is a variation of the standard rivet. This one-piece threaded counter-bored tubular rivet can be anchored entirely from one side of the material in which it's installed. Used to securely fasten metals, fiberglass or rigid plastic materials by creating permanent threads and is ideal for materials considered too thin for tapered threads