mikestock wrote:
I have had mechanics and one person who builds competition airplanes swear that torque wrenches are inaccurate when an extension is added. To me, this flies in the face of the Action, Equal and Opposite Reaction Law. Just wondering if anyone has seen any explanation for this widely accepted phenomenon.
It depends on a couple of things
For a torque wrench to be accurate the wrench must have a more or less specific relation to the bolt.. That is the extension must come straight off the bolt to the head. Any 'Side torque' on the extension will cause the readings to be off.
If using a common torque wrench you need to provide a fulcrum for the head of the wrench (left hand) to insure it is straight to the bolt.
NOTE: Wrenching with side torque....
I once had to change tires on a Ford F-350 Custom (10,000 pound) using the wrench supplied (The one bolted to the fender under the hood) I put the wrench on and shoved the bar through the holes and put uneven pressure on the thing so not only was there twist but side torque as well. That bolt whish is about the size of my XXXL thumbs snapped like a pencil.
The other 9 I made sure I applied even pressure to both ends of the rod so the torque was rotational only.. Put the new tire on.. Poor tire store guy had a heck of a time removing it with his big air impact wrench.. Seems I over torqued them a bit.
