Tub overflow plate screw spins freely and won't go in or out

Question

I'm trying to screw in a new overflow plate to my tub. We recently bought this house, and it didn't have an overflow plate at the time. I tried to screw in the new plate, but about halfway though it started spinning freely without going in. It won't unscrew either: just spins freely. The white plastic part is not spinning. How can I fix this?

I've tried screwing and unscrewing it, with normal amounts of force and as much as I can apply. When unscrewing it, I tried pulling on the plate.

I looked at the plumbing behind the wall (there's an access panel) but that was unilluminating.

Here's a video of me trying to unscrew or screw in the plate.

Answer 1

The force required to cut new threads into the untapped plastic fitting overcame the strength of the existing, newly-cut threads. In other words, you stripped the threads you had cut before getting all the way through.

You'd have avoided this by keeping adequate pressure on the screw, ensuring forward movement as you turned and sparing the few threads that had been cut by the screw from undue force.

Now, you'll just have to yank out the screw and try again. Pull hard as you twist back and forth. It'll bring the stripped material out with it, which you'll need to clean from the screw. When you run the screw in again, keep some force on the screw to cut the rest of the threads, but don't push so hard that you crack it off. Don't overtighten once you do get all the way through--the threads are now minimal.