At the grocery store where I work, the walk-in freezer doors/doorframes got banged up over time, so they fixed them.... The way they did this was by taking the old door & latch off, and by putting a whole new door frame+door inside the old opening.
Recently I noticed that the new frames are all held on by plastic allthread rods. Why is this?
See pics here-
The second pic is a close-up of one of the plastic allthread rods, and the (metal) nut and washer attaching it. You can see that the plastic charred a bit from being cut with a power saw. The inside of the rod (visible inside the freezer) is done exactly the same as the outside. All the doors they fixed were done this way--with plastic bolts (w/normal zinc-steel nuts & washers) holding the door frames in, but metal bolts everywhere else.
???????
I thought maybe it was a safety-breakaway sort of thing, but these coolers are constructed VERY flimsy. I'd give it about a 50/50 chance of the nuts just pulling through. Is there some other reason, or is that all?