Gunsmithing How many threads is enough for 65 in/lbs???

[sr15match]

OK, here's the deal. How many threads of an action screw (SA Remington) need to be turned in to be considered safe to torque to 65 in/lbs?

I know more is better but after bedding the action and making an adjustment to my floorplate I've lost some depth.

Thanks - Todd

 

[LoneWolfUSMC]

Re: How many threads is enough for 65 in/lbs???

New screws are cheaper than helicoils.

 

[Victor N TN]

Re: How many threads is enough for 65 in/lbs???

Machinist rule of thumb is the length of threads = the OD of the screw. 1/4" screw needs to be in at least 1/4" deep.

Have you ever considered using 50 instead of 65? You're tight. Everything is locked in place. But you aren't as likely to pull threads.

 

[dinc]

Re: How many threads is enough for 65 in/lbs???

40 to 50 in/lb is probably better for an epoxy composite bedded rifle. 65 in/lb is for the rifles being tightened into a metal bedding block. 3 complete threads is minimum but will require frequent checks to make sure it has not loosened. Go shoot.

 

[dontstrokeme]

Re: How many threads is enough for 65 in/lbs???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Victor N TN</div><div class="ubbcode-body">Machinist rule of thumb is the length of threads = the OD of the screw. 1/4" screw needs to be in at least 1/4" deep.

Have you ever considered using 50 instead of 65? You're tight. Everything is locked in place. But you aren't as likely to pull threads. </div></div>

Do not use less than this ......longer screws are extremly cheap...ebay had some longer standard screws for BDL metal and any good hardware store will have the socket head cap screws....if they are too long determine the correct length...put a nut on it and cut the excess off and clean up the threads with a file...as you take the nut off it will clean the threads up if they are buggered....the longest nut you can find is best.

 

[BLAWTON]

Re: How many threads is enough for 65 in/lbs???

With a 28 pitch thread you will need 7 turns to get to 1/4"

 

[sr15match]

Re: How many threads is enough for 65 in/lbs???

I think I might just pick up another screw and cut it to the length desired.

It's cheap and easy (kind of like me).

Thanks guys.

 

[sobrbiker883]

Re: How many threads is enough for 65 in/lbs???

1/4-28, I use socketheads on all my R700's now.

 

[fewenuff]

Re: How many threads is enough for 65 in/lbs???

If I recollect correctly, USAF TO's say 4 threads showing or equivalent and you are good to go. So count the threads inside the nut/hole and add 4 full turns. An aircraft standard but I've used it for years and can barely spell helicoil.

 

[nashlaw]

Re: How many threads is enough for 65 in/lbs???

Good info, here. I have thought four was GTG, but I am happy that others agree. I always seem to "lose" a thread or two when bedding.