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I was thinking about some new finger buttons. What is the standard thread pitch for tuba valve buttons? Is there a standard? The ones on my BMB horn are M5 x 0.8, and I’m guessing this may be out of the ordinary. Any ideas to help me spiff up my ride?

MikeS wrote: ↑Sun Jun 18, 2023 12:35 pm I was thinking about some new finger buttons. What is the standard thread pitch for tuba valve buttons? Is there a standard? The ones on my BMB horn are M5 x 0.8, and I’m guessing this may be out of the ordinary. Any ideas to help me spiff up my ride?

M4 X .7 is common with the Europeans.
We quit making ours, because various European makers "interpretation" of that thread tends to vary, and people would (rather than buying a $5 Chinese tap on eBay, and chasing their stem threads) gripe at us, send our stainless buttons back to us, and have us re-cut their threads down to slightly-under the standard diameter.

Some older European button threads are SAE 8-32.

Yamaha threads are M4 X .75

Many American buttons are SAE 8-32. (King, Olds, Reynolds)

I dunno about Martin tubas/sousaphones, and nor do I know (for absolute certain) about Selmer USA sousaphone button threads. (I might guess SAE 8-32 re. Selmer USA).

Holton are SAE 6-36 UNLESS the stems have been replaced with Olds O-99/Bach 869 stems (which take SAE 8-32 buttons).

The 20K/2XJ "short-action" threads are SAE 12-32

Conn standard-action threads are 6-40.
OTHER-THAN Conn buttons (with the correct thread) will offer a different "throw", because there's a bit of "valve stem" (above the threads) built into Conn standard-action buttons.

The M4 X .75 thread is the closest metric thread to SAE 8-32, and - with some patience, working back-and-forth, and without re-tapping, Yamaha buttons can be "worked into" SAE 8-32 stems.

bloke "TMI, and some may be wrong. "

King buttons do thread into Martin stems (at least on Eb sousaphones and Eb Helicons) a bit tight but go in alright.

I’ll check Martin Mammoth stems later.

York-aholic wrote: ↑Sun Jun 18, 2023 5:58 pm King buttons do thread into Martin stems (at least on Eb sousaphones and Eb Helicons) a bit tight but go in alright.

I’ll check Martin Mammoth stems later.

I always forget about Jupiter... SAE 8-32

If Martin "almost accepts SAE 8-32, they could possibly (??) be 8-36, but it seems to me that 4 TPI difference would be too much of a struggle (??)

I have no idea what this is: https://www.ebay.com/itm/265388755604

The Martin tuba/sousaphone valve stems that I've seen have been elongated versions of their trumpet (designed to screw into a spring barrel) valve stems, with a roughly 1/4 inch high appliance (as if the top part of a trumpet piston spring barrel) brazed in place to accept them.

The Martin Mammoth and full-size sousaphone bore size has always puzzled me.
Is it .719", or is it something else?
If .719" (??) that's metric - 18.25mm
If metric (??), then the finger button size could also be metric (same as Yamaha M4 x .75), which would explain why SAE 8-32 buttons "almost" fit into Martin stems.

Sorry, the pictures are in the wrong spots but you’re all smart boys and girls do will figure out what should have been where…


Martin Eb sousaphone valve tops (1952ish):

The Eb Martin helicon (serial number points to 1925 but an engraving suggests otherwise) has “normal” valves, ie no riser on top of the piston.
That engraving is slightly off center and a different “font”. I suspect it may have been done after it was manufactured.

I had some Martin trumpet valve stems that I salvaged from one of those Imperial model trumpets back when we had a brick and mortar store. At the time they were still one Martin sousaphone in service in a suburb of Memphis, and every once in a while they would trash a valve stem. I brazed extensions onto those and used those to replace those that they trashed on that instrument

York-aholic wrote: ↑Sun Jun 18, 2023 7:48 pm Sorry, the pictures are in the wrong spots but you’re all smart boys and girls do will figure out what should have been where…


Martin Eb sousaphone valve tops (1952ish):

IMG_3044.jpeg


The Eb Martin helicon (serial number points to 1925 but an engraving suggests otherwise) has “normal” valves, ie no riser on top of the piston.

IMG_3045.jpeg

That engraving is slightly off center and a different “font”. I suspect it may have been done after it was manufactured.

Do you reckon that the Class of 1933 went ahead and engraved the school helicon as a senior prank...?

Beats me. The engraving is well done, I just don’t see Martin engraving it off center. It is a bit ‘crisper’ than the original bell engraving.

Veering way off course…

So, to sum things up, the answer to the question “Is there a standard?” is “No!”. Right?

arpthark wrote: ↑Sun Jun 18, 2023 9:36 pmThat engraving is slightly off center and a different “font”. I suspect it may have been done after it was manufactured.

Who knows how long it was in stock? Or perhaps they bought it used and donated it because it was needed. Just sayin'...

Most every brand has a standard. LOL

YorkNumber3.0 wrote: ↑Wed Jun 21, 2023 6:07 am using an acorn thread cutter to get underneath the button skirt.

You can get in serious trouble for that these days.