Luger Grip Screw Thread Size - Page 2

sheepherder · 03-04-2017, 12:13 AM

As described in my thread on this subject some time back, both a 3/16"-30 and a 3/16"-32 tap would thread holes that the three threads of a Luger grip screw would comfortably fit in.

The #10-32 would not go all the way in.

IMO having the correct size Whitworth tap is nice but not essential for only three threads.

From the Luger blueprints in TBLAP -

DonVoigt · 03-03-2017, 03:58 PM

The first screw machines they bought were from the UK, at least that is what I read.
Whitworth predates "standardized" metric pitches, IIRC.

The luger screws and threads are a hybrid, metric diameters and TPI. Whitworth is a 55 degree angle thread, the current standard is 60 degrees, so depending on the use/tolerance/number of threads, a 30 TPI Whitworth will "fit"(close enough) a 30 TPI modern thread.

Changing the gearing from TPI to metric is a bear and old "english system" lathes just won't do it.

CAP Black · 03-03-2017, 03:59 PM

Why would it matter to you? Do you want to know the
history of industry in
Europe from the 1700s?
That would be a lot to learn. Many people that come up against this during current times have the same bewilderment.
Let it go.
Also read the thread above and get a portion of it.
Jack

Zorba · 03-05-2017, 11:29 PM

Quote:

Originally Posted by CAP Black

Do you want to know the history of industry in Europe from the 1700s? That would be a lot to learn

Yes, as a matter of fact!

Such things interest me.

Kiwi Mark · 09-02-2017, 12:38 AM

I have made grips screw by screw cutting the lathe. At the time, I found them to be 0.010" under 5mm and 0.8mm pitch. Just checked my taping chart and they are 3/16 x 32 tpi or 3/16 BSF.
Yes, I know, what are the very clever Germans using a Englander thread. That I don't know??
Maybe a Reasonable Knownable Person can answer??

Kiwi Mark · 09-01-2017, 07:09 PM

I made a pair of grip screws. They are 0.010" small than the 5mm screw, but 0.8mm pitch. I used a 60 deg screw cutting tool.
Not Whitworth as they are too course.
I'll about to make some more with over size heads so as to stop the grip movement. Standard ones are 0.420" diameter

John Sabato · 09-08-2017, 04:40 PM

The best metal fabrication and manufacturing machines made at the time it was initially designed and produced were made in England... does that answer your question Mark?

Diver6106 · 09-10-2017, 12:00 AM

IF YOU READ the Practical Machinist thread noted above, it explains why Germany would use a British thread on their screws. It is a GREAT read!

03-03-2017, 03:58 PM	#2
DonVoigt User Join Date: Apr 2015 Location: near Charlotte NC Posts: 4,681 Thanks: 1,443 Thanked 4,356 Times in 2,041 Posts	The first screw machines they bought were from the UK, at least that is what I read. Whitworth predates "standardized" metric pitches, IIRC. The luger screws and threads are a hybrid, metric diameters and TPI. Whitworth is a 55 degree angle thread, the current standard is 60 degrees, so depending on the use/tolerance/number of threads, a 30 TPI Whitworth will "fit"(close enough) a 30 TPI modern thread. Changing the gearing from TPI to metric is a bear and old "english system" lathes just won't do it. __________________ 03man(Don Voigt); Luger student and collector. Looking for DWM side plate: 69 ; Dreyse 1907 pistol K.S. Gendarmerie

03-03-2017, 03:59 PM	#3
CAP Black User Join Date: Dec 2008 Location: Fairmont, WV Right here in Mountaineer country and God's country Posts: 767 Thanks: 100 Thanked 174 Times in 96 Posts	Why would it matter to you? Do you want to know the history of industry in Europe from the 1700s? That would be a lot to learn. Many people that come up against this during current times have the same bewilderment. Let it go. Also read the thread above and get a portion of it. Jack Last edited by CAP Black; 03-03-2017 at 04:00 PM. Reason: add info.

09-08-2017, 04:40 PM	#7
John Sabato Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: The Capital of the Free World Posts: 10,156 Thanks: 3,003 Thanked 2,309 Times in 1,098 Posts	The best metal fabrication and manufacturing machines made at the time it was initially designed and produced were made in England... does that answer your question Mark? __________________ regards, -John S "...We hold these truths to be self-evident that ALL men are created EQUAL *and are endowed by their Creator* with certain UNALIENABLE* rights, and among these are life, LIBERTY, and the pursuit of happiness..."*

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03-04-2017, 12:13 AM	#1
sheepherder Lifer Lifetime Forum Patron Join Date: Feb 2009 Location: ...on the 'ol Erie Canal... Posts: 8,208 Thanks: 1,425 Thanked 4,474 Times in 2,343 Posts	As described in my thread on this subject some time back, both a 3/16"-30 and a 3/16"-32 tap would thread holes that the three threads of a Luger grip screw would comfortably fit in. The #10-32 would not go all the way in. IMO having the correct size Whitworth tap is nice but not essential for only three threads. From the Luger blueprints in TBLAP - __________________ I like my coffee the way I like my women... ...Cold and bitter...

09-02-2017, 12:38 AM	#5
Kiwi Mark User Join Date: Jan 2017 Posts: 23 Thanks: 0 Thanked 7 Times in 6 Posts	I have made grips screw by screw cutting the lathe. At the time, I found them to be 0.010" under 5mm and 0.8mm pitch. Just checked my taping chart and they are 3/16 x 32 tpi or 3/16 BSF. Yes, I know, what are the very clever Germans using a Englander thread. That I don't know?? Maybe a Reasonable Knownable Person can answer??

09-01-2017, 07:09 PM	#6
Kiwi Mark User Join Date: Jan 2017 Posts: 23 Thanks: 0 Thanked 7 Times in 6 Posts	I made a pair of grip screws. They are 0.010" small than the 5mm screw, but 0.8mm pitch. I used a 60 deg screw cutting tool. Not Whitworth as they are too course. I'll about to make some more with over size heads so as to stop the grip movement. Standard ones are 0.420" diameter

09-10-2017, 12:00 AM	#8
Diver6106 User Join Date: Sep 2014 Location: Mt. Vernon VA Posts: 246 Thanks: 1,436 Thanked 119 Times in 76 Posts	IF YOU READ the Practical Machinist thread noted above, it explains why Germany would use a British thread on their screws. It is a GREAT read!