Luger Grip Screw Thread Size

[gvt1911]

I have a few frames that could use a clean out of the grip screw threads...Does anyone know the correct size tap/s to buy..??? GPC lists their replacement grip screws as M5 x 0.8 pitch ....???
TIA

[Norme]

It's an obsolete Whitworth thread, good luck finding a tap!
Norm

[mrerick]

Some info here:

http://www.practicalmachinist.com/vb...screws-221376/

[John Sabato]

Originally Posted by mrerick

Some info here:

http://www.practicalmachinist.com/vb...screws-221376/

Just a note of interest to readers of this thread...

the User named as "biometrics" in the thread that is linked above by mrerick was ME!

[Jim Solomon]

Check with Hugh Clark, I think he has info about the screw size and also possibly a tap. Jim

[ithacaartist]

Originally Posted by sheepherder

What short memories you people have...

I bought the proper tap about four years ago, at around the time this was discussed back then. It wasn't too hard to find. I'm sure they're still available somewhere, but as Rich suggests, I can't remember the source of mine. Same fate for the info of which Whitworth size and thread it is, as well. John S's blueprints reveal it, I'm sure.

[gvt1911]

I believe the following will "work"....

http://www.tapsndies.com/tap/tap-3-16-30.html

[G.T.]

Hi Joe, if you're going to order some, get me a set as well? Or, if only one, get the taper tap? I guess depends on cost... but, I'm in if you want to do the ordering?....GT....

[G.T.]

Hi to all, .......I know it seems kind of rude to randomly request a member buy something for you... and that is not what I want to convey, I have some history with Joe.. so I think, maybe, it's ok?... ... we shall see! ... best to all, til...lat'r...GT...

[DonVoigt]

Originally Posted by G.T.

Hi to all, .......I know it seems kind of rude to randomly request a member buy something for you... and that is not what I want to convey, I have some history with Joe.. so I think, maybe, it's ok?... ... we shall see! ... best to all, til...lat'r...GT...

GT,
I'll see if the "British" seller will ship here.
If so I'll get at least 3 or 4 taps.

If the answer is yes, I'll start a new thread and see if others want one also.

But in the mean time, the difference in 55 and 60 degree threads will not be significant for the 3 threads of that diameter in the frame.
So if you have/buy a current std 30TPI , it should be just fine.

[Chickenthief]

http://www.tracytools.com/taps-and-d...roduct_id=1057

[ithacaartist]

Originally Posted by Chickenthief

http://www.tracytools.com/taps-and-d...roduct_id=1057

That's the ticket! ...if they export to the US.

It also appears that the threads are larger diameter than the shank, which is handy for getting the best shot at restoring the threads while minimizing the material removed. I recommend running completely through the good thread and chasing the buggered one from the inside out.

[sheepherder]

Originally Posted by ithacaartist

I recommend running completely through the good thread and chasing the buggered one from the inside out.

I used this method for a buggered-up/cross threaded Luger grip screw hole. The tap thread was short enough to 'free-bore' once it cleared the 'good' threaded hole. I also used an old worn/dull 3/16"-30 tap as I wanted to push the metal back in place rather than cut it. Used oil, came out fine.

[Chickenthief]

My link is to tap/die in correct 3/16" diameter 30 TPI Withworth 55deg thread form.
What more do you need?

http://www.tracytools.com/taps-and-d...roduct_id=1057

[DonVoigt]

Originally Posted by Chickenthief

My link is to tap/die in correct 3/16" diameter 30 TPI Withworth 55deg thread form.
What more do you need?

http://www.tracytools.com/taps-and-d...roduct_id=1057

Since they are in the UK, do you know if they ship to the US and the shipping charge?

That is what I "need" to know; and thanks much for the link.

[CAP Black]

The Whitworth tap for Luger grip screws is not obsolete. There seems to be enough help provided to make a purchase, if not I will see if I can find my data for the right tap. But a little tip to help: If one side of frame hole is O.K. start the tap from that side and go through the mag well into the damaged side (after applying a drop of oil, of course) and re-thread the side needing straightened out. Slow and easy is a key.
Jack

[CAP Black]

I got mine (Whitworth items) right here in West Virginia. They might still be in business.
Jack

[CAP Black]

The Whitworth tap, etc. can be purchased at: Sabatelli Precision Grinding, 312 Sabatelli Drive, Mt. Clare, WV 26408. Phone: 304 622-8915.
I don't recall the exact size of the threads or other specs of the opening in Luger grip screw holes.
Jack

[Zorba]

Ok, I'm confused. I thought Whitworth was a British thing. Why would the Germans use it? Obviously, there's some factoid I'm missing...

[Ron Wood]

Originally Posted by Zorba

Ok, I'm confused. I thought Whitworth was a British thing. Why would the Germans use it? Obviously, there's some factoid I'm missing...

At the time, the Brits were ahead of Germany in product standardization. The Whitworth thread was a documented industrial standard and Ludwig Loewe adopted that standard not only for grip screws but for barrel threads as well. Loewe also looked to the USA for standards for mass production as was initiated early on by Eli Whitney. Loewe wanted to produce quality and interchangeability so he wasn't reluctant to stand on the shoulders of those who had already been there, done that.
Ron