roof clearance lights

That is just an expandable rivet. Yes, now that you show the Teardrop style clearance light, that is how Tiffin installed them. I thought you had the older Bargman rectangular lights. That is what confused me. Doug

rgatijnet1 wrote:
It is similar to a Rivnut but I don't remember seeing a Rivnut that is split. I know there are Rivnuts with a floating nut plate.

You are quite right regarding a Rivnut. You are also right about the trifold poprivets not leaving behind a threaded nut. However the molly jack nut can be installed using a tool that looks exactly like a wellnut or rivnut tool.

It's mainly a matter of who calls each of the other blind rivits.

Here is a link for the Jack nut which is in effect a trifold rivet.link

It is similar to a Rivnut but I don't remember seeing a Rivnut that is split. I know there are Rivnuts with a floating nut plate.

to jpmihalk, et al, wellnuts do not have as large a diameter head on the outside of the skin or as large an expansion on the inside. They are really intended for use in thin metal and the head on the outside is much thicker than a Jack Nut which is really a "Molly" Jack Nut and was introduced by the makers of Molly Bolts. Link

A nutsert used to be called a blind nut and is used extensively in electronics for building enclosures.

I have a 12" toolbox from Lowes full of these different threaded fasteners.

Do you mean a "well nut" or a "nutsert?"

There is a proper name for those nuts and for the life of me I cannot remember the name. I'll go to the garage and get one out and find the name. They work on the same premise as a molly or a poprivet that is split and I cannot remember the proper name for the poprivet. The nut I'm talking about leaves a treaded piece to use screw to mount with. Back in a moment with the answer on edit.

The correct name is Jack Nut. They are used to create a mounting in thin materials, especially plastics and fiberglass.link

Here is a site with the rivets called trifold blind rivets. The trifold does not have threads remaining after the rivet is expanded. Much stronger than a plain pop rivet, which by the way were very popular in England before they were here in the US. On looking at the pictures again, I thin what you have is a Trifold poprivet. On first look at the devise that held my door lock actuators on my F150 they looked like they used a screw in the cent wut it was the shank of the poprivet.

I have used Jack Nuts to provide a screw mounting in the filon skin of my Bounder where there wasn't any stud to attach to.