How much is too much for a 3/8 breaker bar?

[guy48065]

Can't seem to find the answer to this question: How much torque can a 3/8" breaker bar handle before it snaps or is considered "abuse"?

A couple recent threads about using 3/8 on lug nuts has me wondering...

Thanks!

 

[3baygarage]

Using 3/8" On lug nuts is not a good idea.

 

[AA/FC]

If it starts to bend, or if the 3/8 drive twists off, thats when you know you've gone too far. Seriously though..... it's 3/8 drive, it was never meant to take tons of torque.

 

[anndel]

I would go with a 1/2" breaker bar for lug nuts. I have an Armstrong 1/2" BB I bought from Amazon.com for $150.

 

[Olafur]

286-375Nm for these:



And since you probably want to use your breaker bar more than once, limiting torque to 70% of max is probably good idea. So not much over 200nm for the average "good" 3/8" breaker bar.

 

[zkling]

Depends on the specific bar and maker.

I would go with a 1/2" breaker bar for lug nuts. I have an Armstrong 1/2" BB I bought from Amazon.com for $150.

You spent $150 on a 1/2" breaker bar?

 

[rlitman]

And since you probably want to use your breaker bar more than once, limiting torque to 70% of max is probably good idea. So not much over 200nm for the average "good" 3/8" breaker bar.

Which translates roughly to 150 ft-lbs for us SAE folks, which is actually quite a bit more than I expected.

 

[APEowner]

I would consider whatever torque you can apply without sliding a pipe over the end as fair game.

 

[pjboy]

husky makes some good breaker bars. hd

 

[hautpot]

I use torque wrenches as a good estimate. My 3/8 drive torque wrench can go max 100 ft-lbs, so i use my breaker bar a little more above that.

 

[lauver]

My old school 3/8" torque wrench tops out at 50 ftlbs.

That is probably a conservative limit for a modern 3/8" breaker bar. You could probably safely add another 10 ftlbs and use 60 ftlbs as the limit for your 3/8" breaker bar.

However, as other have mentioned, automotive lug nuts are generally tightened to about around 70 to 90 ftlbs, and frequently are tightened even higher by the apes at the tire shops with their impact wrenches. This is clearly 1/2" driver breaker bar/socket territory.

Hope this helps

 

[exmaxima1]

I would go with a 1/2" breaker bar for lug nuts. I have an Armstrong 1/2" BB I bought from Amazon.com for $150.

How did you manage that? The 18" Armstrong BB costs less than $50 most anywhere, including Home Depot:

http://www.homedepot.com/p/Armstrong-1-2-in-Drive-Flex-Handle-Breaker-Bar-12-918/204826438

http://www.amazon.com/dp/B00004WAKJ/?tag=atomicindus08-20

 

[ganymede]

Every lug nut I've ever done has been a chore. Never thought about using 3/8 drive on them.
Always 1/2 drive. Before I discovered the wonders of breaker bars I used a 4 way and a couple of times when that stripped them, a pair of vice grips.

 

[bimmerZ5]

$20 http://www.harborfreight.com/12-in-drive-25-in-professional-breaker-bar-62729.html

 

[Bigstevex4]

my dad was a Mac tool man. He use to tell me they can break any thing. He and I were Heavy equipment mechanics. I've broke some stuff mostly sockets. If it breaks it breaks just don't put yourself in a position that if it does you'll get hurt.

 

[theoldwizard1]

I have been a shade-tree mechanic for about 50 years. Never had a 3/8" breaker. Never needed it.

 

[ChevyEFI]

Before he had an injured shoulder, Dad used the same SK 3870 to remove / install lug nuts as he used for everything else.

 

[Shiftless]

Unless you're in a tight space without room for a long handle, you should be using 1/2 inch drive tools for that kind of work.

BTW, full retail price for a Snap On 24 inch breaker bar shows $123 on their website.
I buy stuff like that at garage sales. I never pay more than 1/4 retail sometimes far less.
(Not a pro mechanic)

Longer bars give you more leverage...simple Physics!
This guy understands the basic principles.

 

[Wakefield]

Depends on the specific bar and maker.



You spent $150 on a 1/2" breaker bar?

You might almost be able to get the Snap On 36" bar for that (too unwieldy for routine lug nut use when the 15" Williams bar takes them off easily)
the old Craftsman bar used to do that duty-might have cost $20. to 30. Has a convenient hole for hanging! (All those are 1/2"drive)
Wright #3439 3/8" drive bar is nice for about $25. plus shipping has a nice bulge handle but wouldn't want to pull it as hard as the 1/2" model

 

[Bagherra]

$20 http://www.harborfreight.com/12-in-drive-25-in-professional-breaker-bar-62729.html

This!!

 

[Bagherra]

What's the difference between a ratchet and racheting breaker bar??

 

[guy48065]

286-375Nm for these:...snip...So not much over 200nm for the average "good" 3/8" breaker bar.

THANK YOU! That's exactly what I needed (an answer...).