thread pitch

cheezhed · July 4, 2010, 03:24 PM

I have a Colt national match with the elliason rear sight. There is a small nut on the windage adjusting screw that fell off after the staking failed and I need to make a new one. I was wondering if anyone knows the thread pitch of the adjusting screw as my place of work is shut down for a bit and my pitch gages are there. I can easily make the part but if anyone can help it will be appreciated.

**Unclenick** · July 4, 2010, 04:49 PM

I've forgotten. Let's figure it out. The windage is about 1 moa per click and the elevation is about 3/4 moa per click on that sight on that gun. The windage is 8 clicks per revolution. The rear surfaces of the front and rear sights are 6 11/16" (6.63875") apart. So. . .

8' = (8/60)° = 0.13333…°,

and that means,

0.13333…°/turn

sin(.13333…°) = 0.002327

1 / (6.6875 × 0.002327) = 64.257

So it looks like 64 TPI is likely. 2-64 is a standard UNF thread, but it certainly could be a special.

July 4, 2010, 03:24 PM	#1
cheezhed Senior Member Join Date: November 28, 2007 Posts: 302	thread pitch I have a Colt national match with the elliason rear sight. There is a small nut on the windage adjusting screw that fell off after the staking failed and I need to make a new one. I was wondering if anyone knows the thread pitch of the adjusting screw as my place of work is shut down for a bit and my pitch gages are there. I can easily make the part but if anyone can help it will be appreciated.

July 4, 2010, 04:49 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	I've forgotten. Let's figure it out. The windage is about 1 moa per click and the elevation is about 3/4 moa per click on that sight on that gun. The windage is 8 clicks per revolution. The rear surfaces of the front and rear sights are 6 11/16" (6.63875") apart. So. . . 8' = (8/60)° = 0.13333…°, and that means, 0.13333…°/turn sin(.13333…°) = 0.002327 1 / (6.6875 × 0.002327) = 64.257 So it looks like 64 TPI is likely. 2-64 is a standard UNF thread, but it certainly could be a special. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; July 4, 2010 at 05:08 PM.