Patent ID: 7832970

Claim:
A friction stir rivet nut in combination with a workpiece, the combination comprising: a workpiece and a friction stir rivet nut, the friction stir rivet nut comprising a material capable of being friction stir welded to the workpiece via a mandrel tool, the friction stir rivet nut further comprising: a body having an elongated cylindrical shank extending between a first end and a second end, the body comprising a first portion proximate the first end and a second portion proximate the second end, the first portion having a first nominal cylindrical wall thickness, the second portion having a second nominal cylindrical wall thickness that is less than the first nominal cylindrical wall thickness; a cap at the second end; and an anti-rotation feature at the cap, at an outer surface of the body, or at both, the anti-rotation feature comprising a void in material forming the friction stir rivet nut; wherein the body and cap have a blind axial hole extending from the first end to the second end, the first end being blind and the second end being open, the first end having uniform internal threads, the outer end surface of the first end having a flat surface oriented substantially perpendicular to an axis of rotation of the shank; wherein the anti-rotation feature of the friction stir rivet nut is metallurgically and mechanically bonded to the workpiece; wherein a metallurgically bonded region between the friction stir rivet nut and the workpiece comprises plasticized material of the workpiece.