Why do screws come loose?

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Tags

1. #force
2. #friction
3. #threads
4. #axial
5. #immediately
6. #often
7. #doesn
8. #reason
9. #loosen
10. #screw
11. #outward
12. #point
13. #pushes
14. #which
15. #screws
16. #metal
17. #proportional
18. #because