Question on Grip Screws

CAP Black · 12-09-2011, 03:31 PM

Here is my experience regarding this issue. I took a gun to a shop that produces taps and sells numerous taps from other producers. They must have dozens and hundreds of different sizes and shapes, types and thread counts. They concluded it is 32 TPI, Whitworth, as I told him I understood it to be.
He used a "starter" tap and gently placed it into the threads in the gun; worked it into what he could feel as the starting point and, just with his fingers, made a quarter of a turn 3 or 4 times and gradually got it taking hold. When it got too tight for finger turning, after visually checking it numerous times, as he worked, he put a "T" wrench on it and worked it through. He only visually checked the screw and put it into the hole and once again gently turned it into place. It worked slick as anything. That was on a 1915 Arty. We repeated it on a 1900 AE with the same results. I bought the "starter" tap for $15 and brought it home to become a new addition to my tool box. Nothing was done to the screw. Apparently from the shape and bluntness of the screw, it is most often that the threads in the hole get damaged - not the threads on the screw.

A.Mifsin · 12-10-2011, 03:51 AM

"I ended up tapping my grip frame with the 3/16" x 32 tap...The Luger grip screw fits just fine... "

Hi Postino, is the 3/16"x32 BSF or Whitworth.
Alf.

ithacaartist · 12-10-2011, 10:51 AM

The way I recall the Whitworth tap I just bought and chased grip screw threads with was listed both ways. BSF=British standard fine, which is the fine version of BSW=British standard Whitworth(coarse thread). So whit.3/16-32 would be the same as 3/16 BSF.
Here's a thought, did the original post seek larger diameter HEADS for the grip screws? I've noticed that this is the case for Erma La-22's; but since I am away from the guns in question, cannot say right now. The Erma grip screws have a significantly larger head diameter, so if thread size and pitch somehow match, they could work where this would be needed--or turned down a tad if the dia. is excessive.
David Parker

A.Mifsin · 12-10-2011, 11:02 AM

Thanks, the problem is I can't find 3/16"x32 Whitworth(BSW), only 3/16" x 32 BSF .
Alf

sheepherder · 05-19-2013, 12:35 PM

Quote:

Originally Posted by ithacaartist

Here's a thought, did the original post seek larger diameter HEADS for the grip screws?

Yes. Here is a copy of the Numrich Luger P-08 parts listing, just for S&G...I only noticed this today (Numrich has a habit of listing 'Not Illustrated' parts wherever they please...)

466070 Grip Screw (.258 OAL, .393 Head Diameter, Thread Pitch M5 x .8; 2 Req'd) $3.55

1430020 Grip Screw (.193 OAL, .344 Head Diameter, M5 x .8) $3.45

1430010 Grip Screw (.214 OAL, .373 Head Diameter, M5 x .8, Beveled) $3.45

I ordered two of the .393 dia screws...I'm doubtful of their thread pitch, but I hope they can read a caliper correctly...

12-10-2011, 03:51 AM	#2
A.Mifsin User Join Date: Dec 2002 Location: Malta Posts: 570 Thanks: 74 Thanked 13 Times in 13 Posts	"I ended up tapping my grip frame with the 3/16" x 32 tap...The Luger grip screw fits just fine... " Hi Postino, is the 3/16"x32 BSF or Whitworth. Alf. __________________ I prefer a Luger

12-10-2011, 11:02 AM	#4
A.Mifsin User Join Date: Dec 2002 Location: Malta Posts: 570 Thanks: 74 Thanked 13 Times in 13 Posts	Thanks, the problem is I can't find 3/16"x32 Whitworth(BSW), only 3/16" x 32 BSF . Alf __________________ I prefer a Luger

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12-09-2011, 03:31 PM	#1
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	Here is my experience regarding this issue. I took a gun to a shop that produces taps and sells numerous taps from other producers. They must have dozens and hundreds of different sizes and shapes, types and thread counts. They concluded it is 32 TPI, Whitworth, as I told him I understood it to be. He used a "starter" tap and gently placed it into the threads in the gun; worked it into what he could feel as the starting point and, just with his fingers, made a quarter of a turn 3 or 4 times and gradually got it taking hold. When it got too tight for finger turning, after visually checking it numerous times, as he worked, he put a "T" wrench on it and worked it through. He only visually checked the screw and put it into the hole and once again gently turned it into place. It worked slick as anything. That was on a 1915 Arty. We repeated it on a 1900 AE with the same results. I bought the "starter" tap for $15 and brought it home to become a new addition to my tool box. Nothing was done to the screw. Apparently from the shape and bluntness of the screw, it is most often that the threads in the hole get damaged - not the threads on the screw.

12-10-2011, 10:51 AM	#3
ithacaartist Twice a Lifer Lifetime Forum Patron Join Date: Mar 2011 Location: Atop the highest hill in Schuyler County NY Posts: 3,409 Thanks: 7,583 Thanked 2,657 Times in 1,398 Posts	The way I recall the Whitworth tap I just bought and chased grip screw threads with was listed both ways. BSF=British standard fine, which is the fine version of BSW=British standard Whitworth(coarse thread). So whit.3/16-32 would be the same as 3/16 BSF. Here's a thought, did the original post seek larger diameter HEADS for the grip screws? I've noticed that this is the case for Erma La-22's; but since I am away from the guns in question, cannot say right now. The Erma grip screws have a significantly larger head diameter, so if thread size and pitch somehow match, they could work where this would be needed--or turned down a tad if the dia. is excessive. David Parker