Barrel threads question

[Jim K]

I often try to answer questions, and hope I do so correctly. But this time, I would like to ask a question of any Europeans who might be with us.

The Mauser 98 barrel thread dimensions are given, even on German sites, as 1.1 x 12 in inches. That is 1.1" major diameter and 12 threads per inch. But isn't the actual metric measurement M28x2.0?

Anyone know for sure?

Jim

 

[QuickDraw]

This may help:
Mauser info

QuicjDraw

 

[Jim K]

Thanks, QuickDraw, but Brownells doesn't speak metric either.

I know what the threads are as usually given here (1.1x12) and everyone says that is "close". My question is "close" to what? Mauser didn't work in inches, so there must be a correct metric designation for that thread size, and I would like to know what it is just out of curiosity.

Jim

 

[Mal H]

Jim, I searched and searched for the metric barrel dimensions as I'm sure you have. I finally ran across the answer - they don't use metric for barrel threads, they use the English system!

SFAIA the thread pitch IS 12 tpi Whitworth form. Not unusual in that the Germans stuck to Inch standard threads for many years..even into present times. For instance the Din 477 standard pipe threads are simply metricised BSP threads 25.4mm diameter and all that!

Quote found here: http://yarchive.net/metal/magnum_mauser.html

 

[Clemson]

Mal is right. Mausers were never made with metric threads. Most WERE cut with the 55 degree Whitworth thread form, but I never had a problem with mating 60 degree standard threads to the 55 degree receiver threads.

Clemson

 

[Jim K]

Well, I found one European web site that gives the major diameter as 28mm, or 1.10236 inches. While that is certainly close to 1.1 inches, 28mm sounds a lot more like what a German manufacturer would choose than 1.10236 inches.

I know about the 55 degree threads, and in fact some barrel makers actually use that - I think Lothar Walther does, but that is also the metric standard.

I have read some of that "they got it from us" also, and it may be true, but then I also recall reading that the Germans got 9mm from the U.S., and that a 9mm Luger would fire the .38 Special(!). I have also read that the 8x57 was a copy of the .30-'06 and could be fired in an M1 rifle(!!).

I'll keep looking and let you know what I find.

Jim

 

[Clemson]

Jim,

The metric system was devised in principle before the French Revolution, but its adoption was fairly slow, even in Europe. The standards were not even distributed to nations that wished to adopt the system until 1889. The Mauser brothers were well-underway with rifle development, production, and sales by then. Germany did not actually adopt the S.I. system until 1969. The old units (i.e., our British units, or the inch-pound system) were legal for use in Germany until 1978.

I can work in either system, but I am most comfortable with units in the British system because that is what I learned and operated with in Engineering school. Students today are generally taught in the S.I. system, and they are uncomfortable working with such wild and crazy units as Btu's.

Clemson

 

[saands]

I know about the 55 degree threads, and in fact some barrel makers actually use that - I think Lothar Walther does, but that is also the metric standard.

Jim: I'm not sure to which "metric standard" you are referring, but all the "standard" metric threads that I have ever run across have had 60 degree threads. I had always figured that the 55 degree on the threads was the real proof that they had used English threads.

I'll be interested in hearing if there is something else going on here.

Saands

 

[Mal H]

Jim, with all due respect, it sounds like you know you have the answer and are only looking for the proof. That proof may not exist in any substantial quantity.

 

[Jim K]

Hi, Mal,

No, I don't play that game. I just keep reading that 1.1x12/60 is "close" or "close enough" to the original Mauser barrel threads. I have worked a fair amount in metric, but gun stuff is usually outside the normal parameters for standards since, at least in the U.S., gun makers were in business before there were standards.

But I thought that Mauser, being in a metric atmosphere, would really have made those threads to a metric specification which, by accident, would be "close" to 1.1x12. So I set out to see what that metric designation was, and have not been able to do so. I think M28x2.0/55 is what it really is, but I was just seeing if anyone knew, either to confirm or correct me.

If Mauser really used a 12 tpi standard, how would a German gunsmith, with a metric lathe, cut 12 tpi? What does he set his lathe to?

Jim

 

[Mal H]

Just curious, did you check out the link in my post? Much of the info is from Robert Bastow of Express Rifle Co. in Smyrna, GA. He may or may not know what he is talking about, but I would lean toward his knowing whereof he speaks. He says in that link:

Remember too that in 1898 Germany was not the Industrial Powerhouse she was to become a few years later..Britain may well have been the nearest, reliable, source for standardised cutting tools.

Makes sense.

 

[saands]

If Mauser really used a 12 tpi standard, how would a German gunsmith, with a metric lathe, cut 12 tpi? What does he set his lathe to?

Well ... first off, we are assuming that your average German gunsmith of the times would be cutting those threads ... maybe it was just an armorer that would have been set up. Secondly, there are no metric lathes or English lathes that I know of ... only gears to cut metric threads and gears to cut English threads ... it wouldn't be inconceivable that someone in the trade would have a gear set to swap out, would it? I've always been under the assumption that the "Almost a 1.1x12" meant that it was almost a 60 deg 1.1x12 and that the error was in the thread profile. Interesting that maybe there is another take on it ... but I'm still waiting to be convinced

Saands

 

[Gewehr98]

Mal, that link you posted...

Thanks for reminding me about the late, great "Teenut". I keep thinking he and Gale McMillan are up there working out a new boltgun design together. Here's more of Robert Bastow, including his shop, before he departed us:

http://teenut.homestead.com/teenut.html

 

[Jim K]

OK, I am convinced. I go around saying, "There is no metric system, it is all a plot by the French", "There is no metric system..."

Someday I will convince myself.

_________________________
"Remember too that in 1898 Germany was not the Industrial Powerhouse she was to become a few years later..Britain may well have been the nearest, reliable, source for standardised cutting tools."
_________________________

The idea that in 1898, Germany was not industrialized and Mauser was so small that they had to use British machines and English measurements does not quite work. In the mid-1890s, German steel production was increasing seven times faster than Britain's and total output was second only to the U.S. Krupp and other arms makers were (pun intended) going great guns.

Mauser had been making small arms for Germany and the world market for 30 years or so. By 1898, it was a subsidiary of DWM, which had huge small arms factories in Berlin-Martinikenfelde as well as Mauser's home plant in Oberndorf a/N. The rapid expansion for the 1898 contract might well have resulted in the purchase of machine tools from England, but they would not have had to adopt the English system along with the tools, since tool makers made their wares to the customer's specifications.

I know of no source saying that Mauser did "Buy British", but whether they did so or not, Mauser was hardly the backwoods blacksmith shop the quotation implies.

Jim

 

[scalinghammer]

I think you will find that before the 1930's thread standards were not realy in place. Not just in this contry. Europe ie. England and Germany and France did not have standard thread sizes, pitches or forms. The general consensis was on 60 degree thread forms. Even then we still have standard thread forms that are not 60 degree. But the diameters were a M28-2 becasue this level of standardization did not occur until well into this century. I havn't got a clue what kind of thread they used but there was more than just a good chance that is was a special Mauser thread.

Ed

 

[JackM]

Have to look this one up, but Turner Kirkland had a note on threads in a Dixe Gunsworks catalog. IIRC, French rifles used during the American Revolution had metric threads and so did later American military muzzleloaders. So the metric system was in use before the French Revolution. Germany used a non-metric system until almost 1900.

Bye
Jack

 

[Jim K]

I have a copy of my late uncle's Complete Practical Machinist, dated 1900, the year he started work as a machinist. It has a breakdown of both American and English (Whitworth) thread standards.

I am a bit surprised at how people seem to think of that era as some sort of crude "chestnut tree" blacksmithing. Just in this country, they were building steam locomotives by the thousands, installing hundreds of hydro-electric generators, wiring the cities for electric light, building electric motors, making the first practical automobiles, building huge steel passenger ships and battleships, erecting steel frame buildings, and making guns like the Winchester 1895, the first Colt-Browning auto pistol, and the Krag rifle. Not to mention making millions of nuts, bolts and screws to hold everything together.

In Europe, they were doing very much the same thing, turning out steam engines, automobiles and all the rest, as well as some very decent guns. Pretty tough to do with no standards on anything, I would think.

By the way, I never said M28x2 was a standard, and AFAIK it is not an ISO standard; I only asked what the metric dimensions were for the Mauser rifle barrel threads.

Jim

 

[Clark]

Keunhuasen's book says there may be some 11.5 TPI 1938 Turk Mauser barrels.
I think I found an earlier one.

 

[scalinghammer]

I realize that there were standards but they were not nessariliarsI realize that there were standards in both Europe and the US but they were not always used. I have had a few machines made from the teens to the late thirties (my father collected them). These were from Germany, England and the US. There were standard threads on them and then there were truly odd threads. The Brits had both 60 and 55-degree vee angle threads and they could use them on the same machine (BSA shaper). The Germans had imperial diameters and metric on the same machine (Krupp grinder). The US manufacturers were no better. Brown and Sharpe had there own complete thread system until 1938. So did Warner Swasey, Bardon and Oliver and others. They are a thrill to work on. Just determining the thread diameter and pitch then finding taps or what not is a task to be lightly taken.
I will bet that in the late 1800’s the thread standards were no better organized than they were 10-40 years later.
Ed