[Spridgets] Torque wrench extension

[BJNoSHOV8]

As an engineer I know more than a little about torque, bending and 
deflection, but I stayed out of this discussion the first time around.

For a mechanical wrench of this type the amount of extension really 
doesn't affect the torque.  You can play with their calculator and it 
will show this as well.  For instance set the lefthand extension to 0 
inches, which is the normal case with a torque wrench, now change the 
length of the wrench to anything you want.  The torque applied to the 
fastener will still equal the torque indicated at the wrench, because 
that is exactly what it is measuring.  With different wrench lengths it 
will take less pull by the user to achieve that torque.  Now if you add 
an extension on the lefthand end of the wrench you will get a different 
answer because now you have the applied torque indicated by the wrench 
plus the force you are applying multiplied by the additional extension.  
I'm not aware that this type of extension is commonly available but if 
it is then their calculator would be very useful to you.  I could write 
the equations to get the same answer.

Now if you are using a BEAM torque wrench, then it is slightly 
different.  The calibration of the beam is based on a predetermined 
bending moment condition in the beam.  If you put an extension on either 
end of that type of wrench then you would change the bending 
characteristics of the beam and get a different answer.

I have experience with both types of wrench and a wrench that clicks is 
certainly easier to use, but a beam wrench that is not damaged and that 
is used correctly will never go out of calibration.


> A short while ago there was a discussion over using an extension bar 
> with a torque wrench.  The below may help.
>
> http://www.belknaptools.com/downloads.asp