[Farmall] calibrating torque wrench

[soffiler at myeastern.com]

Sorry to chime in late on this one:

I agree with Carl on pretty much all counts.  I could
conceive of some sort of kludge to check calibration using a
weight affixed a known distance from the wrench axis, yada
yada, but it would be just that, a kludge.

Calibration adjustment tends to cost in the range of $25 per
wrench and can be done by the following outfits:

Angle Repair, Beckley WV 304-253-5729
Team Torque, Bismarck, ND 888-682-6875

Oh, one final comment:  the beam-type wrenches are far more
stable than click-type.  With the beam-type, the torque
reading is based on the deflection of a steel beam.  Unless
that beam is physically damaged, its deflection
characteristics do not/cannot change.  I personally wouldn't
send a beam-type to a calibration house.


Best regards,
Steve O.


From: szabelsk at gdls.com
----- Original Message Follows -----
> Calibration needs to be done by somebody who has the
> correct equipment.  I know some people try to calibrate by
> tightening a bolt with a known good wrench, and then try
> to calibrate by loosening with the wrench they are trying
> to calibrate. This doesn't work since the torque to loosen
> a bolt is different then the torque to tighten a bolt.
> Also keep in mind that different torque wrenches have
> different accuracies. Getting two different reading with
> two different torque wrenches doesn't mean either one is
> good or bad, it's a matter of being within the tolerance
> range for the wrench. You could be on the high end of
> tolerance for one wrench, and on the low end for the
> other. Sometimes the accuracy changes with the torque
> range.
> 
> Testing by snapping bolts also won't work, since the
> listed breaking strengths of bolts are average numbers,
> and the actual breaking strengths of a batch of bolts can
> vary greatly.
> 
> I have no idea what somebody would charge to calibrate a
> torque wrench, but if you decide to do one, you may want
> to consider doing both.
> 
> Carl Szabelski