Gunsmithing 1/2” Torque Wrench

[PBWalsh]

Hello,

Going to be assembling my first AR upper. I need a 1/2” driver to torque my barrel nut on. with the included Geissele wrench. Going to order a Geissele reaction rod or similar for holding everything on the vice. Just want to make sure this barrel gets torqued properly without going by feel and “seems snug enough”.

Not needing something that will get used often, just need every so often. Say once every 2 years for barrel changes and other odd tasks.

Thanks for any advice and suggestions!

 

[Hobo Hilton]

Rent one, borrow one or steal one.... After you do the first one you will get a "feel" for how tight it needs to be and never need one again.

Hobo

 

[jackinfl]

Harbor Freight

 

[PBWalsh]

Can’t tell if joking... based on HF reputation.

 

[pmclaine]

My tool philosophy is that if I think I will only use it once, maybe twice, Ill borrow or rent it.

If I think it will be needed three times or more Ill buy it.

If Im going to buy a tool my soul like nice things. If you have ever held the sweetness of a Snap on wrench.....

one of these in hand is a beautiful thing. From my working on my own motorcycle days I have ended up with these in 1/4 and 1/2 inch drives.

Try to buy one of these used off Ebay than bring it by a Snap On truck and see if they can check calibration/recalibrate if necessary.

 

[fdkay]

The harbor freight wrenches are serviceable. (I have one)
Just remember, anytime you add an attachment that increases length (no matter how short), it changes the value of the torque.
Most firearms related torques have a generous +- factor, as long as it is consistent.

 

[fdkay]

Here is a review after 8 years use.

 

[GH41]

"Just remember, anytime you add an attachment that increases length (no matter how short), it changes the value of the torque "

If you turn the wrench 90 degrees to the shaft of the torque wrench nothing changes.

 

[fdkay]

Torque Wrench Calculator for Extended Adapter with Formulas

 

[fdkay]

"Just remember, anytime you add an attachment that increases length (no matter how short), it changes the value of the torque "

If you turn the wrench 90 degrees to the shaft of the torque wrench nothing changes.

There is still an increase between the very center of the torque wrench and the tool.
It is VERY slight and of no consequence for what we are talking about.

 

[chevy_man]

The oem for snap-on without the tool truck price.

CDI Torque 2503MFRMH 1/2" Drive 30 - 250 lb 24" Dual Scale Micrometer Adjustable Torque Wrench

The CDI 2503MFRMH is a dual scale, calibrated, dual direction torque wrench that is easy to set and features quick release buttons for easy socket retention and removal. With a drive size of 1/2', it has an English range of 30-250 ft-lb and an NM range of 47-332.

www.toolup.com

Or here's a solid digital option.

Professional Grade Digital Torque Wrench | Brown Line Metalworks

Brown Line Metalworks The only wrench engineered for the seasoned professional but priced for the weekend mechanic.

brownlinemetalworks.com

They're not expensive. I say that because I spent $110 on a 3/8” drive Mac ratchet that came off the tool truck. Driver got lucky I hand just busted my knuckles with a crapsman and thrown it into a field.
I now only buy quality ratchets. Haven't busted a knuckle since.

 

[PBWalsh]

Thanks for the suggestions, now time for a stupid question.

Can you take a 1/2” wrench and convert is to a .750” sheepsfoot? Edit... I mean crows foot.

 

[fdkay]

Thanks for the suggestions, now time for a stupid question.

Can you take a 1/2” wrench and convert is to a .750” sheepsfoot?

Not familiar with the term sheepsfoot.
Do you mean crowsfoot?

 

[PBWalsh]

Duh.. yeah thats right... I meant crows foot.

 

[fdkay]

Yes, adapters for increasing or decreasing the attachment size have no bearing on torque value (it is inline with the tool head).
The slight increase of torque value of the crows foot is likely calculated by the manufacturer, as I said, in this instance, it does not make any difference.
It is more likely to keep you from over tightening.

 

[PBWalsh]

Ok, thank you. I think for my limited use, the HF might actually be ok without jumping to a "better" brand such as Kobalt.

 

[2aBaC̶a̶]

My next one will have the adjustable crescent end for all the odd shit.

 

[Wannashootit]

Just like I won't buy cheap chinese indicators, I wouldn't buy a cheap chinese torque wrench.
HF's fine for me, for anything that won't see much use and precision isn't required. Couldn't do without my $250 HF horizontal band saw...

If you haven't yet needed a decent torque wrench and don't anticipate after this, rent one from your local Auto Parts store for a few bucks.

 

[Arc Light]

Torque wrenches are one area you shouldn't skimp on, imho. I have about 5-6 torque wrenches from 1/4" to 3/4" drive and they are all US made. Most I've had for 10+ years and they are still in calibration. China Freight stuff might be ok for putting on your wheel lug nuts, but I would not trust anything purchased there for critical work.

I suggest looking at CDI as they are made by the same parent company that makes Snap-On, but much more affordable. Excellent quality and US made. If you take care of them, they will outlast you. Here's one as an example (you can get them cheaper elsewhere btw): CDI 1/2" Torque Wrench

 

[fdkay]

Torquing a barrel nut is NOT critical work.
Many folks just tighten them by wrench.
The only thing a torque wrench will do here is prevent him from over tightening and give him a consistent torques value if he installs a different barrel.
He's not building the fucking space shuttle.

 

[2aBaC̶a̶]

More often than not it will depend on gas tube timing also so torque is +/-

Check out the Real Avid tool similar to the Geissele reaction rod only less expensive. Save money on that and you can afford a better torque wrench.

 

[Arc Light]

Then go ahead and buy a $15 HB torque wrench and take your chances.

When it doesn't click over (has happened to MANY, MANY people) and you apply 3X-4X the required torque, well hey, you saved a few bucks.

 

[ken226]

An ar15 barrel nut needs at least 35 ft lbs, up to a Max of 80.

Just hit 35 ft lbs, then align the next tooth.

I have expensive torque wrenches, but they aren't necessary for an ar15 barrel nut.

 

[hino895]

Yep torque to 35 lbs, line up gas tube, tighten gas block, insert 30rd mag and make it smoke......done

 

[brianf]

Not being a AR guy, but if you use the heating the receiver method is the torque that critical?

Seems to be that method produces great results

Thanks

 

[E. Bryant]

Try to buy one of these used off Ebay than bring it by a Snap On truck and see if they can check calibration/recalibrate if necessary.

I strongly agree with this advice. Otherwise, hit Amazon for a CDI torque wrench - this brand is owned by Snap-On, and they made pretty good stuff.

FWIW, if the torque range is under 100 lb-ft, then a decent 3/8" torque wrench is al that is required. The general rule of thumb is to never use a torque wrench to achieve a value less than 20% of the wrench's maximum rating. I can't even dial my 1/2" Snap-On wrench below 50 lb-ft.

As a side note, I'm mystified that any adult male can get through life without a decent 1/2" torque wrench, because that tells me that someone doesn't have the capability of properly torquing an automotive lug nut. To me, that's a pretty damn important capability.

 

[TheBigCountry]

@PBWalsh just snag the Real Avid AR kit form Midway for 199 or so. It comes with the torque wrench and a bunch of other tools to assemble your rifle. I’m doing it myself right nkw

 

[bfm1851]

Wow, I have built several AR,s over the years and never used a torque wrench. Guess I really did not know it was needed?? Before retiring I work as an industrial mechanic and I guess I got use to knowing how tight was tight. But then again never had to work on any space shuttles.

Just a disclaimer, I do use a torque wrench when install scopes and bases.

 

[B y r o n]

Here is something to consider. Look at the spec's for 2 torque wrenches:

"Accurate to ± 4% clockwise and ±6% counterclockwise from 20% of full scale to full scale"

"Accuracy ±4%"

So one will cost you over $400 new while the other will cost you $20 or less.

Now I'm not trying to say that both will have the same quality in construction or feel during operation but both claim, at least through spec's, to produce the same result. For occasional use if you can't borrow one the lower cost unit should serve you just fine.

I own both ends of the scale and don't have a dog in the fight. You just need to decide what you feel comfortable with.

 

[candyx]

Liquid Torque Wrench ........ Red Loctite