Originally posted 2 July 2018 on www.W5SWL.com
Some folks just have to have Teflon. Some don't know what Delrin is and some don't care. I personally don't see much difference in my shack when it comes to Delrin or Teflon.
Delrin is a excellent insulator and is a machinable dielectric. It has higher strength than Teflon, but it has a bit more loss than Teflon. Of a comparison of Bakelite, Teflon and Delrin, Delrin has the most loss.
Teflon has a lower dielectric constant than Delrin and a "bit" less loss. The dielectric constant of Teflon is 2.1 and that of Delrin is 3.7.
Teflon definitely has a higher melt temperature when it comes to soldering.
So for me, if I am using solder connectors and installing them I am not afraid to use either Teflon or Delrin, but Teflon gives me margin for heat errors (as in cooking the connector). Around my shack, for adapters and such, unless I am hunting every fraction of a dB for some reason or using a lot of RF power, Delrin is just fine and meets my pocket book better.