bore sizes - dumb post...

[Dan Schultz]

Sometimes when I get bored working on horns..... and I started thinking about weird (read: dumb) stuff again:See? I told you that this was going to be a dumb post. The point ...I guess (again) just that most of these "mysterious" decimal bore sizes are just "plain ol' " sizes.

Well, Joe... I tend to think of bore sizes as being based around what diameter brass tubing was available at the time... thoughout the manufacturing realm... as opposed to the tubing being manufactured specifically for the music industry. Not to mean that some of the alloys weren't a bit special... but rather to say that the equipment that the tubing is/was produced on is/was the same as is/was used in many other industries. Some had metric and some had English dimensions depending mainly on which part of the World it was produced in. As far as tubing goes, the machinery is pretty much the same... just with different draw dies and mandrels. The fact that some metric and English sizes are close or the same is just a coincidence... like 5/16 and 8mm.

[Philip Jensen]

I bet it boils down to image/marketing. By using a fraction it makes the instrument sound more industrial and mechanical - after all, those are the terms they use in machine shops. etc. - greasy unsophiticated places

Now decimals, that's way more fancy and technical and surely the instruments made to decimals instead of fractions are clearly made with much higher craft, if not true artistry!

My favorite example is when the press is trying to make something sound more dramatic than it really is (or someone is presenting statistics on behalf of their position)

Example:
Fifteen hundred people will be without power...........
versus
one thousand five hundred people...........

15 hundred is way more than 1 thousand 5 hundred

Car dealers use just the opposite technique!

Only sixteen, nine, ninety-five. Way, way, way, cheaper than Sixteen thousand, nine hundred and ninety-five

I liken these to optical illusions only they're auditory "illusions" The numbers are exactly the same, only they "sound" like they are different.

Philip "who sounds about how he looks" Jensen

[ThomasDodd]

Only sixteen, nine, ninety-five. Way, way, way, cheaper than Sixteen thousand, nine hundred and ninety-five

And we all should know that that really $17,000, but all those 9s make it sound like a deal.

Saw a marketing study, and people actually think that $9.99 is a better deal than $10.
So much so that they'll drive 15 minutes to buy something for $9.95 instead of $10, easily spending more than they save for gas.

It get more pronounced as the numbers get bigger too. so 9,999 v. 10,000 is a bigger deal than 9.99 v. 10, though is really less so (1/10,000 v 1/1000).

[ThomasDodd]

The point ...I guess (again) just that most of these "mysterious" decimal bore sizes are just "plain ol' " sizes.

But who want's to buy plain old stuff? I want the fancy smancy crap.
I mean really, would you rather buy something with an accuracy of only 1/64" or the precision of 15.6 thousandths of an inch (0.0156").

[Joe Baker]

I bet it boils down to image/marketing.

I bet it boils down to the reading on a dial caliper. I think Dan is right about the tubing sizes being what is locally available, but (among Americans, at least) it's easier to discuss if we use a single unit of measure: .001 inches.
_______________________________
Joe Baker, who thinks this is a good thing, as it would be hard for most of us to compare fractional inches and mm.

[Chuck(G)]

Well, we certainly don't want to go "metric" as that's a French invention. Inches are confusing when done to the right of the decimal point.

How about "gauge"?

[ThomasDodd]

Well, we certainly don't want to go "metric" as that's a French invention. Inches are confusing when done to the right of the decimal point.

How about "gauge"?

Sounds good. I'll take a 10ga Tuba then.

Perhaps we should just think of it as caliber instead?

Thinking of my trombone as a 50 cal has a nice ring too it:)

[Tubaryan12]

Bloke,

Can the same be said for mouthpiece throat bores?

[MartyNeilan]

My late grandfather was a machinist who spoke of everything in terms of "thousandths of an inch." That was just the lingo of his trade.

[Rick Denney]

- The old York "Monster" small .650" bore was really just 16-1/2 mm...' maybe not real "familiar" to U.S. folk, but conceptually quite familiar to European folk.

- The "peashooter" .640" bore found on a few tubas is just 16-1/4 mm...another common size in Europe.

I look at the history when considering such things.

These are two that I suspect relate to metric dimensions coincidentally. Nearly all tubing used in machine processes before the 30's was dimensioned in inches. Even quite a bit of machine tooling used in Europe after WWII used SAE threads, simply because metric threading tools were not available.

I'm curious as to what Dan (ex-machine tool maker) would think about the .650 tubing. It doesn't line up to fractions of an inch, but I wonder if it lines up with a gauge dimension. Or, maybe it's .75 OD tubing with .05 wall thickness.

And I don't think reporting them in three decimal places before about 30 years ago would be related to dial calipers. In those days, everyone used vernier calipers and micrometers. But the point is the same. The vernier calipers I have from those days reads in quarters. The scale reads to the nearest .025", and you use the vernier scale to read between the .025" divisions. Thus, it's hard not read them to the nearest thousandth. With the dial (or with digital), dropping precision one decimal place at a time is a lot easier. Thus, .025" is too big a unit for the needed accuracy, so it gets measured to the nearest .001. (Gee, I hope I'm remembering that vernier scale correctly. Come to think of it, it might read in divisions of .0025", though calipers really aren't accurate enough for precision to the nearest .0001".)

Rick "thinking measurement tools often dictate precision rather than report it" Denney

[MaryAnn]

Rick "thinking measurement tools often dictate precision rather than report it" Denney

Reading about micrometers and stuff in your post I was reminded of the year I spent in the machine shop between schools while getting my BSEE. I used a micrometer all the time to make sure what I was making was within specs. The interesting part was it did have slop in it and if I was not ready to dress the wheel yet I would manage to still have my punches within spec.

MA, thinking the user of the tool also dictates the precision

[Chuck(G)]

- The old York "Monster" small .650" bore was really just 16-1/2 mm...' maybe not real "familiar" to U.S. folk, but conceptually quite familiar to European folk.

When I've bought brass (or any other metal) tube from wholesalers, the "nice even number" almost always refers to O.D., not I.D. --and it was the O.D. that had the guaranteed (i.e. spec-ed) dimension. So, if you're looking for a certain I.D., you figure wall thickness and calculate the O.D. and cross your fingers. I've got a few hunks of 0.0.29 wall 5/8" OD tubing and the I.D. differs by about 0.002".

FWIW, that York Monster Eb bore would be about a 16 shotgun gauge--a 24J wouild be about 10 guage horn.

[Chuck(G)]

I think Rick's S.A.E. exploration is a better guessed explanation of the .650" (or so) bore Yorks:

Outside slide O.D. = .750" (the "common" size - 3/4")
Outside slide I.D. = .702"
Inside slide O.D. = .700"
Inside slide I.D. = .650" or .650+"

I am just typing without having anything in-hand to measure, so there is a good chance that these "guessed" specs are total B.S.

Try an O.D. of 11/16" (standard size), 0.015 wall gives you 0.6575--pretty close to that 0.655/0.660 York.

23/32" with an 0.015" wall gives you 0.689".

25/32" gives you about 0.751" ID

Just a guess here, too. When I get a chance, I'll haul out the calipers and see.

[Kevin Hendrick]

- The old York "Monster" small .650" bore was really just 16-1/2 mm...' maybe not real "familiar" to U.S. folk, but conceptually quite familiar to European folk.

FWIW, that York Monster Eb bore would be about a 16 shotgun gauge--a 24J wouild be about 10 guage horn.

So my old Cerveny 601's an 8-gauge ... that explains a few things!

[Dan Schultz]

I'm curious as to what Dan (ex-machine tool maker) would think about the .650 tubing. It doesn't line up to fractions of an inch, but I wonder if it lines up with a gauge dimension. Or, maybe it's .75 OD tubing with .05 wall thickness.

Dunno... I find it very difficult to apply logic to most industrial standards. Maybe the .650 ID evolved from generic 11/16" (.6875") OD tubing with a .019" wall thickness. After all... the tough part about making tubing is doing the rolling and and welding. From there all that is necessary is to anneal the tubing and draw it. Draw dies and mandrels are cheap compared to the tubing fabrication equipment. In the case of matching slide tubing, both the inside and outside slide tubes may have begun with the same size tube... with just different draw dies. The only REAL tubing making experience I have is to design some equipment for a company that produces steel tubing for refrigeration. There... the basic requirement is 'how many feet can you make from a pound of steel strip'. Your guess is as good as mine

BTW... I took a look at Machinery's Handbook and the only mention of gage sizes in the production of tubing relates to wall thicknesses. That was Birmingham or Stub's Iron Wire Gage for seamless brass... Brown & Sharp Gage for welded brass... and in Britain, Standard Wire Gage for some steel tubing.