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View Full Version : Fastener Torques: Dry or Lubricated?



gotwheels
03-11-2011, 04:25 PM
I am a DIYer and use several Haynes manuals. I just completed some front end work on a Plymouth Voyager and try to follow good practice and finish torque fasteners to the specified number. Are the stated torque numbers for component fasteners (which match the factory manuals) based on a dry fastener or a lubricated fastener?

I have read that the applied torque number should be 10% to 25% lower for a lubricated fastener. This was stated (and I assume also) and based on the published component fastener Torque numbers being based as a dry fastener.

Please clarify this for me - am I under-torquing fasteners by reducing the torque value due to lubricated (anti-seize) fasteners?

Thanks

admin
03-11-2011, 04:39 PM
Hello gotwheels,

All torque specifications in our manuals are given as dry (no lubrication) unless otherwise specified.

gotwheels
03-11-2011, 04:51 PM
Hi Admin, Thanks for the prompt reply. Do you have some ~ rule of thumb for adjusting the torque value for a lubricated fastener (light anti-seize)? If I torque at 80% of the "dry" value, should I be OK? I think lubrication of most fasteners is important for future dis-assembly, dis-similar metals, corrosive environments, etc. I try to clean fasteners before reassembly (wipe off, wire brush, at times - some solvent). Your feedback is appreciated, understanding that nothing is exact and that exceptions will exist.

admin
03-11-2011, 07:35 PM
Hello gotwheels,

After a brief bit of online research, I find that some individuals have looked very closely at this issue. Considering that we always adhere to the manufacturer's specifications regarding fastners, that's our rule of thumb here... Here are a few sites that might offer a few more ideas for you:

http://home.jtan.com/~joe/KIAT/kiat_2.htm

http://www.mechanicsupport.com/bolt_torque.html