
I bought a threaded insert kit of ebay, similar/same as rivnuts but quite cheap. Link here
http://www.ebay.com.au/itm/141469061617 ... EBIDX%3AIT
Comes with M3, M4, M5, M6 and M8 inserts in steel and aluminium plus an installing tool with all the right madrels. The kit is quite cheap (and it shows in the rivet gun!) but I figured it would be pretty hard to get the threaded inserts wrong, and if the tool was rubbish it didn't really matter because you can install them without it anyway, albeit a bit slower.
Turned out the tool was quite cheap looking but it still worked fine, it doesn't require alot of force to pull the inserts in anyway so I'm happy enough with it. The inserts themselves are very good, steel ones have the same zinc finish as the new bolts kit I bought of ebay.
When it comes to installing them, probably the most important thing is to drill the correct sized hole. If it is too big I can see the insert losing its grip and spinning around in the hole. For the M5 inserts I measured their OD at 7mm so I used a 7mm drill which is the perfect size. I tested one to see how much torque you needed to spin it around, and I rounded off the bolt head first


I got these sort of as an experiment but having used a few today to replace crappy old self tapping screws, I have realized how absolutely brilliant they are

