TromboneChat

Looking for the spec on Edwards 547 and 562 leadpipe threads...

I see from the archives that Shires/Kanstul coarse is 11/16-18 but couldn't find any numbers for the fine standard.

Thanks!

I believe the fine thread equivalent for that diameter (0.687 inches) is 11/16-24

https://www.machiningdoctor.com/threadinfo/?tid=75

Thanks, but do you know that the diameter is the same?

I know Edwards and Conn/Greenhoe are the same pitch, but different diameters - but I don't have the numbers for either.

Are they a different diameter? My Edwards leadpipes fit perfectly in my Greenhoe horn. Hmmm? Maybe I need to try the opposite….place a Greenhoe pipe in my Edwards!?!?

Crazy4Tbone86 wrote: ↑Sun May 28, 2023 8:09 am Hmmm? Maybe I need to try the opposite….place a Greenhoe pipe in my Edwards!?!?

Well, I was remembering or misremembering this (Conn also = Greenhoe, ¿right? ...) :

hornbuilder wrote: ↑Sun Jan 17, 2021 5:05 pm Edwards and Conn are the same thread pitch, but are different diameter, with the Conn being larger than Edwards. This means an Edwards collar will screw into a Conn receiver, but will be loose. Conn does not fit into Edwards.

In any case, if someone has some Edwards digits I'd be very grateful.

Just tried putting a Conn/Greenhoe leadpipe in my Edwards bass. It does not fit......as Matthew stated, slightly too large. I have only owned my Greenhoe (horn and leadpipes) for a couple of months now. I guess it is a combination I have not tried yet. You learn something new everyday!

Here are the measurements on my threaded collars:

Edwards: Crest = .675, Root = .665

Conn/Greehoe: Crest = .689, Root = .679

Crazy4Tbone86 wrote: ↑Sun May 28, 2023 9:36 am Edwards: Crest = .675, Root = .665

Great, thanks. 24tpi as suggested above?

ithinknot wrote: ↑Mon May 29, 2023 6:14 am

Crazy4Tbone86 wrote: ↑Sun May 28, 2023 9:36 am Edwards: Crest = .675, Root = .665

Great, thanks. 24tpi as suggested above?

Actually...no! I just measured both the Conn/Greenhoe and the Edwards at 32 threads per inch. I also cut a couple of new collars last summer for my Edwards bass and remember that it was 32 tpi.

Crazy4Tbone86 wrote: ↑Mon May 29, 2023 7:13 am

ithinknot wrote: ↑Mon May 29, 2023 6:14 am Great, thanks. 24tpi as suggested above?

Actually...no! I just measured both the Conn/Greenhoe and the Edwards at 32 threads per inch. I also cut a couple of new collars last summer for my Edwards bass and remember that it was 32 tpi.

As I suspected. Looked finer than 24 just from photos. Thanks very much for your help!

(Currently dealing with a mystery pipe situation and some threads that could be described as either 39/64 x 34tpi or M15.5 x 0.75, either of which is very much Not A Thing.)

Ah....that makes sense. I had a mystery bass pipe come through a year or two ago. It was slightly too large for the customer's Bach 50. I think it might have been a German make because the outside of the leadpipe was in the .566-.567 (14.4 mm) range. Fortunately, the metal was a thick gauge, so I was able to sand it down to fit in his .562 slide. The collar had a some type of a metric pitch on it, but I did not need to deal with the threading. He wanted it replaced with just a simple press-fit collar. All ended well, I think he is still using that particular leadpipe.

Good luck with this!