Patent ID: 8888429

Claim:
A clinch nut for attachment to a plastically deformable metal substrate, said clinch nut comprising: a body portion with a central axis and a punch portion extending from said body portion and coaxial with said central axis, said body portion including an annular-shaped surface encircling the central punch portion, said annular-shaped surface including a plurality of spaced apart lugs encircling the central punch portion, one of the lugs including at least a contact surface with a recessed portion wherein the contact surface engages said metal substrate; a first portion of the contact surface being biased in a rotational direction about the central axis upon insertion in the metal substrate to form at least one lug flare during attachment of said nut to said metal substrate; and upon insertion in the metal substrate a portion of the metal substrate being entrapped between the at least one lug flare and the body portion, wherein the recessed portion has a larger width at a location radially closer to the punch portion than at a location radially further away from the punch portion.