Installed the 4" Beckson (# DP40-B) Smooth Screw-Out Marine Deck Plate in my HVAC box today....as per the thread in the Sticky thread over on the DTR....

Link to thread...

http://www.dieseltruckresource.com/f...-twist-298318/

What mine looked like when done. Only took about 30 min...and that was because i didn't have a 4.5" hole saw, so had to cut by hand.