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The proper way to fix such threads is to drill them out a bit bigger then use a thread repair insert like Timesert (better)or Helicoil (easier to find).
A way that often works and doesn't require as much time and money is to try and use coarse thread 1/4" SAE bolts. They are just a tad larger than 6mm (guessing at what you are working with) and have different threads. The best way to try them is with a thread chaser style tap, NOT a thread cutting tap. A thread chaser tends to force aluminum into shape versus how a regular tap cuts it away. You can't afford to lose more thread material. Admittedly, neat as they are to have, most folks don't have a set of thread chasers. So just try threading such bolts in. I've done it. It will either work or not. If you can get one to work for you then you probably want to replace all those bolts with something that doesn't look like it was scavenged from a dishwasher or something. Take your sample bolt to about any hardware store and match the size and thread you need with some allen head bolts. If the bolts don't tighten up enough to give you warm and fuzzies but do sort of tighten, give each a drop of blue LocTite and like as not they will be fine.
A rather jackleg method is to strip a fine stranded copper wire so you can get at the strands. Clip some off and put them in the hole. Then force the original bolt to thread in past them (with a drop of LocTite is best) until the bolt is "snug". Not tight, if you really tighten it it will just pull everything out again. But after the LocTite sets it will probably not fall off.
In an emergency situation I've clipped the pointy ends off a zip tie or two and forced them into the hole with the bolt like the copper wire method. Which sometimes worked, at least for a while.
There are epoxy fixes that you can thread into but the one time I experimented with one it didn't hold for me. Might work in a different situation though.
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