Trigger Guard Screw Thread size

B

belldanndy

Well-known member
I have a damaged byf42 receiver screw hole need to re-thread, but i don't know the size of the thread, any information on the thread size? Thanks, regards Kelly.
 
I found some answer with 1/4-22 threads and tap with 55 degree, but I am not sure.
Any advise on where I can get this tap? Thanks.

Regards Kelly
 
Let me assure you, you won't find a non-metric thread on a K98. German manufacturers used metric screws, occasionally with a smaller pitch (fine threaded screw). A 1/4" screw is 6.35mm in diameter. Germans never used odd diameters. In the 6mm range screw sizes usually came in 1mm increments, such as 4mm, 5mm, 6mm, 7mm. Below 3mm chances are you'll find screws in 0.5mm increments, in the 1mm range you can find 0.1mm increments (mostly for watches and optics).

If you re-tap with a 1/4 inch you're going down the same path others before you did when they forced aftermarket cleaning rods with inadequate thread pitch into original cleaning rod nuts, ruining the latter ones in the process.

Tomorrow I will take a look at a trigger guard screw under an optical comparator, then I will be able to exactly tell you the diameter and pitch of the screw.
 
GunKraut said:
Tomorrow I will take a look at a trigger guard screw under an optical comparator, then I will be able to exactly tell you the diameter and pitch of the screw.
Click to expand...

GunKraut, while you're graciously taking your time doing this, could you do the same for the lock screws?
Cheers,
HB
 
Hambone said:
GunKraut, while you're graciously taking your time doing this, could you do the same for the lock screws?
Cheers,
HB
Click to expand...

The correct thread size for trigger guard screw for mauser rifles is 1/4" - 22.
I think that this kind of thread is only used by Mauser and it is not possible to find any standard tool to reprocuce these particular screws. The only factory I know of that produce tools that could reproduce such screws, is this german factory http://www.triebel-guntools-shop.de/
It is very expensive but tools are excellet quality.
I hope this helps.
Regards
 
trigger guard screws

belldanndy said:
I have a damaged byf42 receiver screw hole need to re-thread, but i don't know the size of the thread, any information on the thread size? Thanks, regards Kelly.
Click to expand...

The correct thread size for trigger guard screw for mauser rifles is 1/4" - 22.
I think that this kind of thread is only used by Mauser (in 96 and 98 models) and it is not possible to find any standard tool to reproduce these particular screws. The only factory I know of that produce tools that could reproduce such screws, is this german factory http://www.triebel-guntools-shop.de/
It is very expensive but tools are excellet quality.
I hope this helps.
Regards
 
Thanks for the link. But I find a bit lost on their site.
Can you point to the location of the 1/4-22 tap.
Thanks for your help!

Regards Kelly
 
trigger guard screw thread size.

belldanndy said:
Thanks for the link. But I find a bit lost on their site.
Can you point to the location of the 1/4-22 tap.
Thanks for your help!

Regards Kelly
Click to expand...



Go to:
http://www.triebel-guntools-shop.de/
katalog download;
Gesamt-Katalog 2012 (Geschaeftskunden);
Now you are inside the pdf catalog, go to the page n. 46 you can find either tap set and dies for screws 1/4"-22.
Product number 4242109 for tap-set and number 4244009 for dies. Let me know if this helped you.
 
Bought a couple 1/4x22 dies from amazon for about $10. They should have taps also. Though I got my tap from Brownell, I liked the dies from amazon better. JL
 
vincenzo3006 said:
Go to:
http://www.triebel-guntools-shop.de/
katalog download;
Gesamt-Katalog 2012 (Geschaeftskunden);
Now you are inside the pdf catalog, go to the page n. 46 you can find either tap set and dies for screws 1/4"-22.
Product number 4242109 for tap-set and number 4244009 for dies. Let me know if this helped you.
Click to expand...

I found it, thanks for your guide. So what's the different between the ones from Brownell or Amazon?
The 55 degree of the thread?

Regards Kelly
 
trigger guard screw thread size.

belldanndy said:
I found it, thanks for your guide. So what's the different between the ones from Brownell or Amazon?
The 55 degree of the thread?

Regards Kelly
Click to expand...

I do not know products sold by Amazon and Brownell. From Italy it is very difficult to buy something overseas because the customs and the time of shipping. Normally the metric system thread has 60 degrees and the anglosaxon system 55. But anyway the tap set sold by Triebel is specific for the mauser action 98 and 96 as well. If the cost is not so expensive you can try to buy the tool from other sellers and you can compare (placing on) the thread on the tap with the thread of the screw, if they copy perfectly you can use it.
 
Both are small dies for refreshing threads. The Brownells die is solid type, Amazon has the split type. The split die has a screw at the split to open it very slightly. Opened it starts easier onto the threads and will leave the screw larger diameter for tight fit. Loosening die screw makes the die cut deeper, in case the trigger guard screw is too hard to turn. The dies are hard to turn (difference in 55 or 60 degree or hard screw?), while the tap take more normal force to turn. Both have given me smoother turning screws. JL
 
jlj said:
Bought a couple 1/4x22 dies from amazon for about $10. They should have taps also. Though I got my tap from Brownell, I liked the dies from amazon better. JL
Click to expand...

Can I use back the original screws after tap the receiver hole?
Thanks!

Regards Kelly
 
I measured the unthreaded cylindrical portion of the trigger guard screw and it's 6.3mm in diameter. The threaded portion is 6.05mm - 6.1mm in diameter due to the threads being rolled rather than cut, which comes out to slightly below 1/4 inch. The pitch is 1.15mm, or almost exactly 22 TPI. I forgot to check the angle, usually the Germans have 60 degrees. A worn 1/4" 22 TPI tap may actually come closest to the original German tool. The O/P was right and I'm surprised! I guess as long as you are just re-tapping a mangled thread the 1/4" 22 TPI will do the job.

Tomorrow I will take a look at the lock screws. I bought some from SARCO and it's always a crap shoot. Half of them fit perfectly, the others bind after one turn.
 
trigger guard screw thread size

GunKraut said:
I measured the unthreaded cylindrical portion of the trigger guard screw and it's 6.3mm in diameter. The threaded portion is 6.05mm - 6.1mm in diameter due to the threads being rolled rather than cut, which comes out to slightly below 1/4 inch. The pitch is 1.15mm, or almost exactly 22 TPI. I forgot to check the angle, usually the Germans have 60 degrees. A worn 1/4" 22 TPI tap may actually come closest to the original German tool. The O/P was right and I'm surprised! I guess as long as you are just re-tapping a mangled thread the 1/4" 22 TPI will do the job.

Tomorrow I will take a look at the lock screws. I bought some from SARCO and it's always a crap shoot. Half of them fit perfectly, the others bind after one turn.
Click to expand...




Actually in my opinion is more important tap then die because is easier to need a re-tap the hole then screw but for sure it is better to have both. I have found in www.amazon.com the die 1/4-22 but not the tap. Would you be so kind to write me the link? Thank you.
Even if I really do not know if www.amazon.com can send this stuff to Italy but I will try.
 
Hambone said:
GunKraut, while you're graciously taking your time doing this, could you do the same for the lock screws?
Cheers,
HB
Click to expand...

Ham, I took one of my better locking screws and here are the dimensions: Outer thread diameter 3.3mm (0.130"), core diameter 2.74mm (0.108"), thread angle 60 degree, pitch 0.6mm (close to 42 TPI). Since the screw has been used, dimensions may be slightly off. Usually the core diameter is roughly calculated as thread diameter times 0.8 for 60 degree metric screws. Therefore I think the locking screw has M3.5 x 0.6 thread.

Next I will do the tiny screws found on ZF4 and ZF41 scopes.
 
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