I have a heating element (essentially a very resistive wire) that has two threaded bolt-like connectors on each end. I want to avoid soldering any components of the heating element, so I asked a friend what would work best for this situation, as the heating element need to be connected to a power supply. He advised that I use two nuts on the bolt to hold what he called an "automotive connector" in place. He didn't know the actual name of this part, but described it as a washer with an extension off of one of the edges, where a wire can be soldered. I was hoping someone could tell me the name of this part, as I am looking for places to buy it.
If you mean this
it's called a cable lug. You usually don't solder them, but insert the cable/wire and use a crimping tool to fix it to the lug.
They also exist with screw terminals:
What you're looking for are ring terminals.
You would usually crimp the wire into these. Although if you feel it necessary, they are solderable.
If you plan to use solder on this connector, you need to be sure that the heating element will not make it hot enough to melt the solder! If that's the case, a crimp would be good enough. Make sure to buy the connector appropriately sized for the wire AWG you plan to use (not related to the size of the threaded bolt) so you get a good crimp.