1905 M&P Thread Damage Fix

Milton · #1 08-29-2020, 04:50 PM

I have the noted revolver( 1922 manufactured ? ) that needs the threads cleaned up in the frame of the revolver where the rear most side plate screw fits.
What size tap do I need for this?

Hondo44 · #2 08-30-2020, 02:13 AM

Quote:

Originally Posted by Milton

I have the noted revolver( 1922 manufactured ? ) that needs the threads cleaned up in the frame of the revolver where the rear most side plate screw fits.
What size tap do I need for this?

For pre WWII I, K, and N frame Smiths, it's a proprietary size: slightly smaller diameter (.118") than a National fine #5 (.122") x 44. So don't run a #5 x 44 too much past the point of the tap or it'll be too big for the original screw.

If you have to go deeper to clean up the threads, get a post war S&W #5 x 44 side plate screw so it's not too loose in the hole.

3 x 48 if it's a .22 M frame

Milton · #3 08-30-2020, 04:45 AM

Thank you very much !!!!!

Hondo44 · #4 08-30-2020, 05:51 PM

You're very welcome!

You won't normally find a 5 x 44 tap at the local hardware store. And you want a "gun tap" with only two flutes. Brownells is a good place to order the tap.

Let us know how it works out for you.

Milton · #5 08-30-2020, 06:45 PM

Thank you much! I was going to call Brownell's next week.As soon as I get things sorted out I will report back about how things went.

Milton · #6 09-29-2020, 10:50 AM

Hondo44, I finally got the proper tap from Brownells and ran the tap in two threads.I did get the screw back in but it was tight.I may have to completely re-tap the hole and find a screw to fit.Thank you again for the help.

Hondo44 · #7 09-29-2020, 06:44 PM

Quote:

Originally Posted by Milton

Hondo44, I finally got the proper tap from Brownells and ran the tap in two threads.I did get the screw back in but it was tight.I may have to completely re-tap the hole and find a screw to fit.Thank you again for the help.

Check with magnification that the screw threads aren't cross threaded slightly.

Also, perhaps the screw is a slightly larger post war replacement and that's how the screw threads in the hole got messed in the first place.

Tap another thread or two and try the screw you have again. If still too tight, keep tapping a little at a time. Just don't go any deeper than needed for the screw to go in and you shouldn't have to find/buy a new screw.

Lay the screw against the tap to 'nest' the threads and confirm the tap matches the screw. But if it's stamped 5x44, it should be right.