TromboneChat

Are Edwards and Shires leadpipes threaded the same, and thus usable on either make of horn of the correct bore size?

No; Edwards and Conn use the same (fine) threads. Shires uses coarse threads. Instrument innovations has an adapter that lets you use both if you're okay with the pipe sitting out a few extra mm. The pipes are also more-or-less functional w/o such an adapter too fwiw, they just stick out a hair and don't trhead in all the way. Perfectly fine for testing to see if the pipe works foryou or not.

Thank, Matt, that's exactly the info I needed. Much appreciated.

Bob

I believe Kanstul pipes, if you can still find them, used the same threading as Shires. I don't know how Rath compares.

Instruments Innovations do a Bi-threaded leadpipe reciever that is awesome! I have one installed on my Bach 50 and it accepts all Edwards, Shires and Kanstul pipes. Rath pipes can screw in most but not all the way. Conn sit in but don't screw in due to a smaller diameter in my experience anyway.

They also make Bi-threaded collars to install on your favourite pipe so it will go in both fine (Edwards) and coarse (Shires/Kanstul) threaded horns.

Plus Instrument Innovations are great guys to deal with as well!