Sheet carrying a welded nut

Claim 1

An article comprising: a sheet having an aperture-forming wall-portion forming a through-channel, an undercut nut having a female threaded bore extending axially therethrough, the nut being welded into the through-channel, of which the undercut nut has a shaft with shaft upper and lower circumscribing side walls, has a circular top having a uniform diameter greater than an upper-end of the through-channel in which the undercut nut is mounted, and has a resulting circular overhanging-edge of said uniform diameter compacted into an upper surface of said aperture-forming wall-portion of said sheet, said overhanging edge of said uniform diameter in its compacted state having spaced-apart points thereof of greater nut-top diameter than of the nut overhanging edge before compaction thereby locking said nut against rotary movement when subjected to torque forces of large magnitude exerted on the nut, said upper surface at said spaced-apart points being indented in its compacted-state to a level below remaining other portions of said upper surface, the undercut nut having a length greater than a thickness of said sheet and having said shaft upper circumscribing side wall undercut within a thickness of said sheet at an uppershaft location, said shaft being undercut to a lesser shaft-diameter than a lower diameter of the shaft circumscribing wall, and lower portions of the wall-portion of said sheet being compacted upwardly and laterally into a welded-contact with the shaft circumscribing side wall, said lower portion being indented.