Gunsmithing posibably the dumbest machining question to date.

[42769vette]

im waiting on the paper work on my first supressor. i have a machinest who will walk me threw threading. im trying to get a grasp on what will be happening before i get there.

the can is 1/2 28tpi. i know the thread count is 28. is the 1/2 the distance from the crown the threads go, or the od of the threads. it seams to me there is a number ill be needing missing, but i would assume there is somthing most the world knows that i dont about these numbers that gives you the 3rd measurment

 

[jasonixo]

Re: posibably the dumbest machining question to date.

Yes- 1/2" is the nominal OD if the threads. When you turn down the muzzle to make the thread tenon, you will cut this diameter to about .492"-.498" instead of .500" for a 2A spec thread. Once you begin threading your 28-pitch thread, your infeed with your cross slide at 29.5 degrees will fit around .026" if you touch off on the .497" tenon. You will want to start checking your fit before you get to .026". If you get a close fit to your can, you may not be able to fit other muzzle jewelry on your rifle if the can isn't cut right. Check your fit with a ring gauge or measure them using the 3-wire method to determine the pitch diameter.

 

[300sniper]

Re: posibably the dumbest machining question to date.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 42769vette</div><div class="ubbcode-body">im waiting on the paper work on my first supressor. i have a machinest who will walk me threw threading. im trying to get a grasp on what will be happening before i get there.

the can is 1/2 28tpi. i know the thread count is 28. is the 1/2 the distance from the crown the threads go, or the od of the threads. it seams to me there is a number ill be needing missing, but i would assume there is somthing most the world knows that i dont about these numbers that gives you the 3rd measurment </div></div>

there are several dimensions used for threads. you have a major diameter which is the maximum measurement you get across the threads. you have the minimum diameter which is the diameter measured between the roots of the thread. you have the pitch diameter which is a measurement taken at a point in the vee grooves of the thread. and then you have the pitch, which is how many threads are in an inch, assuming a sae thread.

you need to know what class of threads the suppressor manufacture recommends. once you now if you need a class 2 or 3, then you can look in a machinery's handbook and find the specs allowed for that thread size, pitch and class. you should also find out from your suppressor manufacture how long the threaded portion should be.

 

[42769vette]

Re: posibably the dumbest machining question to date.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body"> you should also find out from your suppressor manufacture how long the threaded portion should be. </div></div>

ok thats what i was trying to figure out. i wasn't sure if the 1/2 28tpi told me that. im hoping to have a few guns pre threaded so i can use the can when it arives.

thanks for the help guys, i really expected some hazzing for that question

 

[cap2031]

Re: posibably the dumbest machining question to date.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">

you need to know what class of threads the suppressor manufacture recommends. once you now if you need a class 2 or 3, then you can look in a machinery's handbook and find the specs allowed for that thread size, pitch and class. you should also find out from your suppressor manufacture how long the threaded portion should be.</div></div>

300sniper,

Most off the shelf style suppressors are Class 2 threads now days, correct? I know Tac Ops suppressors are Class 3 (the time and fit theirs to your rifle most of the time) but haven't seen any others that are, have you?

Class 1 is too loose for recoil and backs off of threads, and from what I hear Class 2 depends on the mating tolerances, sometimes you need teflon and sometimes you don't, but Class 3 you don't need teflon. If I'm off base let me know.

 

[300sniper]

Re: posibably the dumbest machining question to date.

i live in california so i honestly don't know about suppressor thread class requirements. i do know if someone is wanting to cut a thread they should know what class it is required to be before they start.

 

[Alderleet]

Re: posibably the dumbest machining question to date.

Cut class 2 unless you have your can already, then cut class 3

I wish I had cut class 2 on my ruger barrel. The smith I had do it made the threads mate perfectly to my can, however any aftermarket thread protector doesnt fit.

Of course, in my infinite wisdom >_>, I neglected to get a thread protector mated to it...

 

[CS223]

Re: posibably the dumbest machining question to date.

Most can manufacturers publish a barrel thread print on their websites & via a .pdf of their manual. If you are going to DIY, practice on a piece of scrap until you get the hang of it. Get a set of Pee Dee thread wires and a good 1" mic (no chicom).

 

[300sniper]

Re: posibably the dumbest machining question to date.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body"> Get a set of Pee Dee thread wires and a good 1" mic (no chicom). </div></div>

yep. and an extra hand or two to hold everything

. i've tried all the tricks to hold the three wires and i am still too much of a klutz to do it with ease. i make sure to put a clean paper towel under my work with measuring with wires. finding and digging a .040" wire out of swarf can be even more challenging than holding the wires.

 

[Straight Shooter]

Re: posibably the dumbest machining question to date.

I wouldn't make a single cut until the can was in hand. It doesn't take that long to thread a barrel and with the can in hand you can time it if you want to.

 

[Don Black]

Re: posibably the dumbest machining question to date.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CS223</div><div class="ubbcode-body"> Get a set of Pee Dee thread wires and a good 1" mic (no chicom). </div></div>

yep. and an extra hand or two to hold everything

. i've tried all the tricks to hold the three wires and i am still too much of a klutz to do it with ease. i make sure to put a clean paper towel under my work with measuring with wires. finding and digging a .040" wire out of swarf can be even more challenging than holding the wires.</div></div>

Rubber bands are your best friend here, friend.

 

[LRI]

Re: posibably the dumbest machining question to date.

I use a dab of grease to hold wires.

 

[300sniper]

Re: posibably the dumbest machining question to date.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Dixon</div><div class="ubbcode-body">I use a dab of grease to hold wires.

</div></div>

a dab of grease to stick the wires to the thread? that is one method i haven't tried but i can definatly see that working. i'll give that a try next time.

 

[LRI]

Re: posibably the dumbest machining question to date.

Yesser.

I like the TriFlow synthetic stuff. It's sold by Heliproz.com in Billings.

We brush our teeth with it around here.

 

[turbo54]

Re: posibably the dumbest machining question to date.

Personally, I like to use a pitch mic.