Blind threaded insert
Nutserts (a la Nut-Insert) or Rivnuts (Rivet-Nut) are just what they sound like – threaded insert for installation into sheet metal.
I discovered them about 4 years ago when building my campervan, where I used them to affix plywood to the floor of the van and also the wall paneling.
This is one of those things that you wish you knew about years earlier. Once you have used them, you find many applications where you would have previously used an inferior technique.
Nutserts are superior to tek screws or pop rivets for fastening into sheet metal. They are slower to install but cannot be beat where strength is important or where you want to later remove the item you are fixing down and don’t have access to the rear side of the sheet where you might otherwise just use a nut and bolt.
Strength comes from spreading the load out, similar to the idea of putting washers behind a pop rivet or normal nut and bolt.
They come in various thread sizes and material strengths (eg high tensile) also with different head styles such as flange or flush (counter sunk).
They can be installed without the special mandrel tool, (using a long bolt and washer) but it is a pain and if you want to install more than a couple, I would highly recommend the proper tool.
I have installed probably over 100 nutserts of various sizes and it’s still going well.
Some unexpected places I have seen nutserts used is for fixings of sub frames into the chassis rails on many cars. Also the water bottle mounts on aluminum framed bikes, which uses a special style of nutsert flange that conforms to the rounded surface of the tube.06/1/16