Earth nut

The present invention relates to an earth nut for use in fixing a metallic part, of which surfaces are coated with paint, to a mating member such as a vehicle body or the like in grounding condition. The present invention has been accomplished to provide an earth nut which has an excellent grounding performance, and which is free from the possibility of losing a grounding function even upon application of a high axial force and is low in cost, said earth nut comprises a flanged nut having a flange, which is formed at a lower end of a nut body to be integral with the nut body, a plurality of projections formed at a lower portion of the flange near an outer peripheral edge of the flange for cutting and peeling off a coating film on a seat surface, with which a bottom surface of the nut contacts, and a plurality of longitudinal grooves provided on screw threads of a female thread portion of the nut body to extend axially of the nut body and having edges on one sides of lines of intersection of the screw threads of the female thread portion of the nut and the longitudinal grooves to peel off a coating film adhered to screw threads of a bolt, onto which the nut are screwed.