The Stovebolt Site Forums The Parking Lot Panels 'N Burbs What is the official name of this type of fastener

Hello,

What is the official name of this type of fastener? Picture of fastener

The fastener is from a:
1954 Chevrolet panel truck drivers side rear side panel inner compartment, the fastener is for rear fender attachment.

Is the nut holder spot welded into place?
How is it held into place?

Thanks