[bombcar]

"Instantaneous breaking force" or whatever it is can get pretty high, especially if the screw has been there for awhile, or there's any oxidation, etc.

Starting with the right driver (with a perfect tip that fits snugly) will reduce the chance of camout and can help remove them, but even then it can be a tricky situation at times.

I personally find that having a really long screw driver helps - I can get more torque without slipping.