[Farmall] calibrating torque wrench

[Mike Sloane]

I agree with Steve and would add one comment: the main reason for using 
a torque wrench (and this applies more to old tractors than modern 
sophisticated equipment) is to apply even tightening of fasteners around 
the head or other large hunk of metal. For that reason, you don't need 
to worry so much about the exact torque being applied as much as having 
all the torque be more or less the same all around (and applied in 
steps, as opposed to tightening one fastener all the way and then moving 
on to the next one). I am sure that many tractor engine heads have been 
tightened down over the years with just the "feel" of the shade tree 
mechanic's arms on a big wrench in lieu of a fancy torque wrench. And 
those engines ran for many more years without failure.

Mike

soffiler at myeastern.com wrote:

> Sorry to chime in late on this one:
> 
<snip>
> 
> 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
> 
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-- 
Mike Sloane
Allamuchy NJ
Email: (mikesloane at verizon.net)
Website: <http://www.geocities.com/mikesloane>
Tractor images: <www.fotki.com/mikesloane>
Work: none - retired

Facts do not cease to exist because they are ignored. -Aldous Huxley,
novelist (1894-1963)