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Need German thread spec translated

Toolroomguy

Cast Iron
Joined
Jul 9, 2010
Location
Wisconsin
[inks Whitworth Gew. 14øx10 Gg”


Is the thread spec on a Quermutter zoll ( crossnut inch) of a Maximat Super 11 lathe.
I googled and found Gewinde=thread, but what is Gg?
 
Should be,Limy...but I'm guessing this is for an early super 11..it had a 10tpi thread with a 14mm diameter 55 deg...if so, switch it to acme or trap IMO.

MMMM? BOTOH Emco never built rubbish, and an acme is the thread for the job, …….after all 14mm is only <> 9/16'' and there are plenty of 10tpi acme much smaller than 9/16.
 
I agree, and I do think they changed it pretty quick...I won't swear to it as I may have been messing with a hack repair job but it *looked* like a factory part otherwise.
 
German for thread pitch is Gewindesteigung, so Gg is probably the abbreviation. Languages with long words certainly need abbreviations.

In the picture of some German threading tools, the one on the right is marked Acme 10 Gg. The third from the right is marked Acme 4 Tpi. Both are RB brand.

Larry

DSC00542.jpg
 
MMMM? BOTOH Emco never built rubbish, and an acme is the thread for the job, …….after all 14mm is only <> 9/16'' and there are plenty of 10tpi acme much smaller than 9/16.

The standard pitch for 1/2" Acme threads is 10 TPI, so taps are easy to get. Other diameter Acme threads have different standard pitches, but inch-based feed screws in machines like to be 10 TPI, so Myford used special 3/8-10 Acme threads and Rivett used special 7/16-10 Acme threads. Hardinge used square threads on their early machines, all 10 TPI with diameters of 5/16, 3/8, and 1/2 inch.

Larry
 
Left handed Whitworth (55 deg.) OD 14mm. Pitch 10 threads/inch.
Gg stands for "Gang" meaning thread.
It is most likely a German - Swiss -Austrian made lathe for export to the US. They would use 10 left threads per inch to make the cross feed advance 0.100" per turn.
 
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Sorry, no. Gg means Gasrohrgewinde, gas pipe thread.

Makes no sense in this case. And (gas)pipe thread is usually abbreviated with single "G"
And Gg would be according to some sources some funny earth drilling equipment thread. "kegeliges Gestängerohrgewinde DIN 20314"
https://www.emuge-franken.com/download/content/Print/Technische_Wandtafeln/ZS10020_DE_RevB.pdf
But that doesn't make sense any better than pipe thread.

But for example in this book Gg is used as "threads per inch" as far as I understand:
Wechselraderberechnung fur Drehbanke unter Berucksichtigung der schwierigen ... - Emil Mayer - Google-kirjat
 
[inks Whitworth Gew. 14øx10 Gg”

Is the thread spec on a Quermutter zoll ( crossnut inch) of a Maximat Super 11 lathe.
I googled and found Gewinde=thread, but what is Gg?

Like others I'm guessing but give the following thoughts.

Linksgewinde (German) = LH thread

Whitworth (55º flank angle) on an old German thread? Whitworth is though the most common thread profile for pipe threads in the world.

10 TPI on a 14mm diameter? That coarse a thread on that diameter sounds unlikely. If it was that "travel" on a 2 start that'd sound more plausible.

The only normal pitches for Whitworth pipe threads are 28, 19, 14 and 11 TPI. Never 10 TPI or anything else.

I'm probably just adding to the confusion but not intentionally.
 
Ordinary Vee threads of 10 tpi or 2.5 mm pitch were certainly used on for cross and topside feed on at least some of the Emco Maximat range. See Emco Emcomat, Maximat & Mentor 7, V7, V7L, V8, 8.4, 8.6 & 10 lathes well down the page. One reason why I turned down one offered at an OK (ish) price when buying something else from a guy. Fundamentally tho' because not enough extra bang for the buck and hassle over the S-B 9A I was running at the time. Emco tendency to save money by under building and thermally over-running motors was more of a concern. Unlike most other breeds swopping in a standard industrial motor isn't super straightforward.

As for EMCO quality. Like all makers at that end of the market the price / performance / capability equation was (and is) complicated when it comes to giving the first purchaser enough bang for his buck to buy your machine rather than another breed. Often a lot of minor spec trimming adds up to a realistic difference on the price tag. Even if it does store up trouble years further down the line.

Personally I don't see any great performance difference between well cut and accurate Vee or Acme form feed threads off this sort of size. OK the Vee will probably wear faster and need replacing sooner but cutting a new Vee thread and nut is a lot easier than cutting a new Acme pair. Frankly using a good quality tap and die with guided feed will probably produce something as accurate as OEM after a couple of years use. Good enuf for most folks. Generally refurb to brand new quality is a waste of effort on most things. Equivalent to used car world "dealer selected, low mileage with factory warranty" level is more the practical mans aim.

Clive
 
To add yet more here. The lens mounting thread on the Leica camera had a diameter of 39mm and a pitch of 26 threads per inch (this was replaced with a bayonet mount system in the mid 1950's.) This thread also became something of a standard for many enlarging lenses.

I have a piece of literature from Rodenstock in which the thread on their enlarging lenses that have a "Leica-type screw thread" is described as M 39 x 26 Gg/1"
 
10 TPI on a 14mm diameter? That coarse a thread on that diameter sounds unlikely. If it was that "travel" on a 2 start that'd sound more plausible.



I'm probably just adding to the confusion but not intentionally.

Well I took it apart, and a 20 tpi gage matches, so you were right.
Maybe I got the wrong print, I will check the other dimensions to see if that is the case.

Thanks for your replies everyone, it was a big help.
 
"Leica-type screw thread" is described as M 39 x 26 Gg/1"

Seems I mistook Gg. The thing is that Gänge or rather Umgänge, revolutions, per length unit are not the way to indicate pitch in the metric system. It should be in plain millimeters such as M 20 × 0,35. The abbreviation Gg is reserved for Gasgewinde which is nonsense in itself because there are no threads in a gas. One can only thread more or less solid bodies, so it has to be Gasrohrgewinde. Gas pipe thread, not gas thread, if everybody follows me.

That’s why mechanics hate me, I work with the thoroughness and discipline of an engineer, also what regards the jargon. Playfulness alright but when I’m at work I am serious. German engineers were better some time ago, those who pushed industry standards.
 








 
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