Does anyone know the deveoped lenth of a 11/2 trap arm? ...
Answers: they come in 12 and 18" length. but you use tubing cutters to cut them down.
Not sure if you are referring to a plumbing trap or even the apology for asking. Most trap arms for plumbing are cut to the length needed. They are slid into the connector at the wall and held in place near a slip nut.