Old timer told me I was over-tightening coax fittings for 5 years

He just said 'finger tight plus a quarter turn is plenty, you're crushing the dielectric' and I thought he was nuts until I actually cut one open to check. Has anyone else had to unlearn the 'tight as possible' habit their first supervisor taught them?

2 comments

2 Comments

riley_schmidt9d ago

Yeah I actually read a paper a while back from one of the big connector manufacturers, Amphenol I think it was, and they had a whole section on torque specs for coax. Blew my mind too because for years I was just cranking them down with a wrench like I was tightening a tire lug. They said the dielectric material actually compresses and changes the impedance when you overtighten. That can cause signal reflection and loss over time. I never would have believed it until I saw the test results showing how much the return loss changed from just a little too much torque. So your old timer was onto something for sure. Your mileage may vary but I've been doing the finger tight plus a quarter since I read that and haven't had a single fitting come loose or cause issues.

keith_rodriguez8d ago

Crank that thing down with a wrench, torque to yield like a head bolt. I've never had a problem doing it that way and neither has anyone I know.