Handle bar rotates on its own. Can’t screw the screw all the way down I have a second hand Peugeot road bike. I noticed the handlebar was rotating on its own, unscrewed the screw, straightened the handlebar and found out it won’t screw back.  Later I found out the screw is a bit deformed which is probably the reason it won’t screw back.

.

Went to my local hardware store and they don’t have this screw. Anything I can do? Are there still screws like this one?, cause these bikes look pretty old.
That’s a tension bolt for a quill stem I think. Is there a wedge shaped piece floating around inside the fork now? You can fish it out with that bolt or maybe flip the bike upside down.



The last few mm of the bolt look stripped which may or may not be an issue. The small bend in the bolt shouldn’t be an issue. 

Try cleaning everything then reinstalling with a dab of grease on the threads and the interface between wedge and stem. Don’t over tighten the bolt.

You can buy a new quill stem at your local bike store or online for not much $. You’ll need to get the right size for your fork diameter.