I'm installing new angle valves under the bathroom sink and wonder if teflon tape is needed on the threads? It seems that it wouldn't be needed because of the way they are designed. Any ideas?

It depends what type of angle stops you are installing:

1. If they are 1/2" Female, than you will need teflon tape on pipe sticking out from the wall
2. If they are 1/2" compression, and you have 1/2" copper pipe sticking out from the wall, then you do not use teflon tape. It is metal-on-metal installation.

The system isn't allowing me to rate your answer, but it's a good answer, the same I got from a friend that I called while waiting. My situation was your #2 answer which I figured was correct. No leaks! Thanks again.