Thread: Torque Wrench
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Old 04-13-2006, 09:24 AM   #11
MNBoxster
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Join Date: Sep 2005
Location: Minneapolis/St. Paul, Minnesota, USA
Posts: 3,308
Quote:
Originally Posted by JackG
The beam type have an additional advantage... they allow you to sneak up on the torque you are trying to achieve. That is especially important when working with aluminum.
Hi,

You're quite correct. But, if using a Click Type, you should ALWAYS torque a Fastener in 3 steps of 1/3, 3/4 and then the Final Torque Spec. This allows the Fastener to relax between settings and allows the Wrench to work through a broader range. Both will insure greater accuracy.

Also remember, unless specified, all torque settings assume a Dry Thread. Threaded Fasteners work by stretching a pre-determined amount and there is a significant amount of friction between the threads to be overcome. If you use any type of agent on the threads - Lok-Tite, Thread Lube, Teflon Tape, or even if it's just greasy, you need to lower the torque value by 50% or you will be overtightening the Fastener, because you've eliminated the friction which the torque spec allows for.

This is a general rule, but if you don't reduce the torque when using an agent on the threads, you will either Shear, Strip or Stretch the Fastener, or worse, strip the Tap, especially if the part is Aluminum. Hope this helps...

Happy Motoring!... Jim'99
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