[Double Venom]

Frank,
How to explain a heli-coil? My attempt: First, it is not a spring at all. It does appear to be a spring at first inspection but there is no gap between the coils. It is actually machined from one piece of steel. The edges could be considered, "sharp", not round as a spring would be.

A Heli-coil is used to repair stripped threads, say in a head. The stripped hole is drilled out, oversized. Then a matching tap, (for the heli-coil) is used to tap out the new over sized hole. The heli-coil is then screwed in a special tool. (Some will use just a screwdriver.)

In essence, you have oversized the original tapped hole, put new threads in (heli-coil) and brought the hole size back to what ever it was originally. Just a note, heli-coils will not "back out", when you remove the new bolt the edges of the heli-coil act like a reverse "chinese finger" gripping tighter and tighter.

A lot of heli-coils will have a "tang" on the bottom that is meant to "break off" once installed properly. It is this small piece that you may have found in your pan.

Any chance of taking a picture and posting it?

Can anybody explain this better than I did?

Still waiting for this one to be solved.

DV