[earbleeder]

I've used them. In my opinion they are far superior to helicoils. I drill straight, tap with oil, clean the hole and insert with alcohol, apply red loctite to the OUTER threads of the insert and oil to the special tap and install. Be careful because its easy to over bore the countersink and the insert will end up below the surface. I have never had one pull out or any other problem with them. I've used them in spark plug holes, cover holes, oil drain plug holes, etc. on bikes and cars. Expensive but worth it to me.