I am trying to embed a load-bearing anchor in a 1-inch foam sheet. The most natural solution would be some kind of threaded plastic pair that fits together, with one end being able to have a rope attached. Something like this:
I don't know what terms to search for, however. I've found promising items searching for "plastic flanges" or "bulkhead fittings" but they either have much too small a flange (e.g. half inch wider than threads), or are only available in bulk. Threads are not required (I'm willing to use pvc cement) but ideally, it'd also be UV-resistant, as this is intended for outdoor use. Is there a more accurate name I could be searching for instead?
In case it's relevant, my specific plan is to add an additional three attachment points to a foam raft such as the following: