<p>A self-attaching fastener including a central pilot, an annular flange surrounding the pilot including an annular groove having bottom, inner and outer side walls, wherein the bottom wall includes a first plurality of spaced anti-rotation elements each having a radial top face inclined above the bottom wall and a second plurality of circumferentially spaced anti-rotation elements each having a radial top face oppositely inclined below the bottom wall and a method of attachment which avoids distortion of the thread cylinder of a female fastener.</p>
