Thread sizes

Alk8944 · #1 12-31-2010, 06:28 PM

This isn't a question, but an answer to everyone who has asked what is the thread size for S&W stock and sideplate screws. This started as a project to make replica stock screw sets that match the old style screws & escutcheons that were deep and had the collar that was flush with the stock surface as the diamond stocks were.

Often I have seen this question asked and inevitably there is a response that thread sizes have changed over time. This is incorrect. After checking several of my S&W revolvers in J, K and N-Frame, wood and hard rubber stocks, manufactured from 1905 to the 1990s when wood stocks made in the S&W "Stock Job" ceased to exist, this is the result.

The thread size for both stock screws and sideplate/yoke screws was 5-44 NF for all guns checked. This is only logical if you think about it.

Surprise! Now you know. And, before someone contradicts this and says that the new style "Yoke screw assembly" has a different thread, that is correct. This post only addresses the original style solid yoke/sideplate screws. Stock screws do vary in length depending on stock style and frame size, but only in length.

500 Magnum Nut · #2 12-31-2010, 07:27 PM

I can't even see that without a good magnifiying glass. .125 diameter that is 44 TPI = 5-44 thread.

I don't even have a tap like that here. That would be tricky to tap being that small & fine...

I leave it to younger eyes.

Armen · #3 01-02-2011, 02:39 PM

When you refer to the newer yoke screws, what year/series do you mean?
thanks,
-Armen

500 Magnum Nut · #4 01-02-2011, 04:19 PM

The new yoke screws have spring and plungers built in.
Around the eighties they were updated, from the basic screw.

Gun 4 Fun · #5 01-02-2011, 04:28 PM

Quote:

Originally Posted by 500 Magnum Nut

The new yoke screws have spring and plungers built in.
Around the eighties they were updated, from the basic screw.

1988 to be exact.

Protocall_Design · #6 09-15-2016, 10:58 AM

What is the thread size of the larger plunger screw?

gmborkovic · #7 09-15-2016, 11:33 AM

Hello Alk, recheck your I&J frame grip screw. Im coming up with 3-48?
That little bug screw (lock screw) on the top plate screw is 4-48.
The 5-44 taps and dies are not at the Ace store.

Protocall_Design · #8 09-15-2016, 11:48 AM

You can order a lot of oddball taps & dies on eBay.

armorer951 · #9 09-15-2016, 11:54 AM

Larger plunger fitted yoke screw is 8X36

gmborkovic · #10 09-15-2016, 12:54 PM

If you order a cheap tap and die, that is exactly what you get.
I get mine out of Gemany and Switzerland at a primo price.
The quality is the best in the world. Dont go cheap on machine tools and gun parts. Pays off in the long run.

JDBoardman · #11 09-15-2016, 02:12 PM

Does anyone know what the thread size is for the rear sight windage screw? I have a Meprolight rear sight, and the stock S&W windage screws will not go through it - they get progressively tighter and ultimately break off. My problem is that the sight screw detent pin jammed in the Meprolight screw, and consequently will not give me "clicks" for adjustment.

sjb66coronet · #12 09-15-2016, 02:24 PM

Not sure about the frame and sight screws,but the older(pre 1970's) J frame stock screws were 3-48.

Protocall_Design · #13 09-15-2016, 02:41 PM

The rear sight elevation and windage screws are #3-80.

benblas49 · #14 11-14-2017, 10:57 PM

what is the thread size on a s&w 460 leaf spring rear site appears to be abt 6 x 40 0r42

drgbike · #15 11-15-2017, 02:18 AM

Tapsanddies.com. They have all the sizes, have puchased from them several time. Not real expensive. Quality seems first rate, buy a couple, drills also, not very common. Remember small stuff breaks. So go slooow! Also helps to have a jig.

stu1ritter · #16 11-16-2017, 08:02 AM

drgbike, that link should read tapsndies.com. Thanks for pointing me there, interesting place.

Stu

Tired Gunsmith · #17 11-16-2017, 01:24 PM

Brownells Encyclopedia has charts ( somewhat dated) showing screw sizes for almost every firearm found at the time it was published.

Hondo44 · #18 11-16-2017, 04:46 PM

S&W standardized it's screw sizes:

The sideplate and stock screws specification change order of March 4, 1942 was just that: a specification change in the standardization of tolerances for screw diameter. A change from old S&W 'smaller minimum diameter' tolerance to the larger minimum standardized tolerance of the #5 National Fine (N.F.) screw diameter (no, the 44 threads per inch did not change). It refers specifically to the sideplate screws (but excluding the bug screw or upper sideplate screw which is a 4-48 pre and post war) and also the #5 N.F. stock screws. Therefore, there CAN BE a difference between 'pre-change' and 'post-change' screws and they CAN measure different diameters. Sometimes they are interchangeable and sometimes not. After 3/4/42 K & N stock screws became #5-44 NF with an upper OD tolerance of .125" and usually measure .122”+or-.

Prewar K & N stock screws were 44 TPI but the O.D. upper tolerance was only .122" but usually measure closer to .119"+or-. Therefore, if you try to use a standard 5-44 or a post war stock screw, they are a bit oversize. One or two thousandths isn't a lot but makes a big difference on such a small diameter. Usually 5-44 /post war stock screws can be made to work by decreasing the OD with fine grit sandpaper.
Just FYI, pre war I frame stock screws are close to a 3-48, but again, slightly smaller in OD. I & J frames became a standard 3-48 until I frames were discontinued and ~ 1980s when J became 5-44 also.

The 1988 new larger yoke retention screw with plunger is 8X36 and non-fitted.