# Thread timing formula thing.

Discussion in 'Gunsmithing Forum' started by hoovco, Nov 11, 2012.

1. ### hoovcoNew Member

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Alright ... so I've been crunching some numbers and such, and I've been trying to come up with this thing to make timing something like a muzzle device easier. This is what I've come up with:

A threaded barrel with a thread pitch of 5/8 - 24 has a 5/8" inch threaded diameter and 24 threads per inch of threaded barrel.

Every 360 degree turn of a device advances the device 1/24th of an inch.

1/24 = 0.04166666666 inch

0.04166666666/ 360 = 0.00011574074

Every degree turned advances the device 0.00011574074 inch

So if my device, torqued down to spec is advanced 45 degrees ahead of being timed, I would have to create a shim that is 0.00520833333 inch.

So my math would look like:

t = threads per inch
deg = degrees advanced
s = shim

(t/360)(deg) = s

Someone check to see if I'm off ... I know there's some machinists and engineering types on here.

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it sounds logical but im no machinist or engineer.

if it works out that way it would sure make timing muzzle devices easier!!

3. ### TxhillbillyWell-Known Member

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Man,You have way too much time on your hands to be thinking that up!
Looks like a .005" shim will do you just about right!

4. ### hoovcoNew Member

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Oops ... It's actually:

(1/t)/360(deg)=s

5. ### willshoumNew Member

.625x24 threads per inch. do you want class 2 or 3.....class 2 A tol. .0012....Class 3 A tol. .000.......

6. ### hoovcoNew Member

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Can you break that down a little simpler for me? I'm not sure I get what you're saying.

7. ### willshoumNew Member

Class 2 thread has a loose fit, class 3 thead has a tight fit, What did I miss, what is the shim for..... OK... .625 devided by 24 = .026......so for every 360 degrees you advance 26 thousnths. Thats on straight threads. Tapered theads you will have to go by pitch dia. and taper per foot......

Last edited: Nov 13, 2012
8. ### willshoumNew Member

A day late an a dollar short. I went to a proctocolygist this morning and he found the problem....... You got it right, a shim of .00525 sounds right. would it not be better to thread it double lead and not have to turn the barrel into next week in order to make it up.....I'm still at a lost as to where the shim comes into play......

9. ### hoovcoNew Member

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The shim is in case a muzzle device like a brake doesn't time correctly.