Originally Posted by The Pol
People use the 1" nut, because it is straight thread, like the element. Pipe thread is tapered... so what you are using will not work in all applications, because after a number of turns, the threads will begin to cross thread. That is the reason for the 1" STRAIGHT thread nut. In some applications a pipe thread will simply not tighten the element suffciently
The element is only attached to the inside wall of the cooler, which is pretty thin. Because of the taper, as you mentioned, I did snug the copper fitting with a wrench, but its far from being a problem. I think I could get another turn out of it.
If someone is concerned, they can test fit it first. If it won't work, take it back.