over sized screw hole, like i was trying to say, 5200 in the holes will make the screw hold, and yes when you want them out , turning them removes the screw. 5200 will come off or out it's not that forever holding. I found it to work well to fix worn out screw hole , just put on screw, screw it in 98% of the way, wait a week then tighen it 100% . it harden up the worn out area. thats my 2 cent.