12-16-2010, 02:26 PM
"Bendy" bits are fine for styrene and will probably last longer if they don't bend which will cause the end to wobble when trying to drill. If you are trying to drill something harder, you need stronger bits. The problem is that the harder the drill bit, the more brittle it will be. We used to have a problem at work with special hardened flywheel bolts breaking when we tried to remove a flywheel from the diesel engines, and both the bolts and the crankshaft were hardened. The company was too cheap to buy good drill bits, so it was a real pita to drill out the broken bolts!