what's a good average torque setting?

[tpolley]

what's a good average torque setting for general applications? does it depend on the size of the fastener? does it depend on the application? is there a "rule of thumb" that says tighten a 1/2 inch bolt to 100ft lbs or a 3/8 inch bolt should be tightend to 85ft lbs.

 

[Moose-LandTran]

it varies massively by application and fastener concerned.

Most VW-Audi Group cars, Mercedes-Benz and BMWs run 110-120nm (~81-89lb/ft) for the wheel bolts.

I'm the only person at work who torques every single wheel nut/bolt..

 

[tpolley]

it varies massively by application and fastener concerned.

Most VW-Audi Group cars, Mercedes-Benz and BMWs run 110nm (~81lb/ft) for the wheel bolts.

I'm the only person at work who torques every single wheel nut/bolt..

i'm referreing to non-automotive applications. say i want to bolt two pieces of steel together with 1/2 inch grade 5 bolts. that kinda stuff.

 

[Moose-LandTran]

That would depend entirely what you're doing then, for things like construction and gas/fluid piping they often compromise between high torque (therefore very tight) and not risking damage or warping something. It depends entirely on the application and situation. Torque will also vary by nut/bolt grade. There are no rules of thumb for torque in general, as far as i know.

 

[alex71]

yes there are.

http://www.engineersedge.com/torque_table_sae_ftlbs.htm

 

[Moose-LandTran]

yes there are.

http://www.engineersedge.com/torque_table_sae_ftlbs.htm

I stand corrected, you learn something new every day.

 

[Mike83]

Be advised that thread lubrication will have a drastic effect on the final tension in the bolt. A well lubricated bolt will take longer to click the wrench and may become overtightened. That is why turn of the nut method is more reliable for uniform tightening.

 

[zuspiel]

yes there are.

http://www.engineersedge.com/torque_table_sae_ftlbs.htm

Thank you! Now there's a table that'll get printed and slapped on the toolbox!

 

[tpolley]

are those ft lbs? so a 5/16 inch grade 5 bolt should be torqued no more than 19ft lbs and a 1 inch grade 5 would be torqued to 587ft lbs?

 

[dcovey]

Here is another one..Plus it's a good article.. About half way through the article is the rule of thumb..

http://www.pirate4x4.com/tech/billavista/NutsandBolts/Nuts&Bolts_signed.pdf

Dave

 

[Moose-LandTran]

are those ft lbs? so a 5/16 inch grade 5 bolt should be torqued no more than 19ft lbs and a 1 inch grade 5 would be torqued to 587ft lbs?

I'm wondering if those sizes listed are thread size or hex size, my guess is thread.

 

[dxdexter]

Be careful using generalized torque tables. They are based on the use of a nut and bolt connection with full thread contact (I suggest minimum two threads exposed). They would not reflect values where the bolt is threaded into dissimilar materials and varying thread contact areas.

As mentioned above lubrication will have an impact on torque requirements.

 

[Charles (in GA)]

Here is some decent reading on the subject, with torque charts for various sizes of bolts and discussion on how plating, etc affects torque readings. All from a torque wrench company.

http://www.norbar.com/Portals/0/downloads/TorqueValueGuide.pdf

Charles

 

[Moose-LandTran]

Here is some decent reading on the subject, with torque charts for various sizes of bolts and discussion on how plating, etc affects torque readings. All from a torque wrench company.

http://www.norbar.com/Portals/0/downloads/TorqueValueGuide.pdf

Charles

Mmmm.. Norbar. If i recall correctly, you have a Norbar or two? I have three and looooove them, you can't find a better torque wrench.