Which is better? Delrin or Teflon?

Some connectors are made to me tightened with a specific torque spec and some are hand tighten only.

Well no, it used to be one of the best because there were few connector manufacturers. And a lot of Amphenol is now made on a China Line.

How many of us have really done this? Myself included ...

In a word, no.

Or why we don't publish specs ...