A Nutsert (or Rivnut) is a female thread (nut) used in thin sheetmetal or areas with no access behind the sheet. It is like a blind rivet and has at one end either a flange or a small countersunk/rimless flange, and a portion of plain barrel. It is the plain barrel that can be compressed behind the sheet metal, thereby forming a female threaded nut fitting fixed through the parent sheet metal.