Re: Torque wrench

[erict@cta.com (Eric Thorstenson)]

Dave asks:
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Just wondering something... Is a torque wrench still accurate when used
with a crowfoot (offset wrench head) instead of the usual socket? It
seems that the rotation center is an inch or so  past the end of the
head when used with a crowfoot. It seems like the wrench would be
calibrated to use a lever arm that ended in the head... do I need to
make any sort of allowance for that?
-----

Definately. The instructions that came with your wrench should
provide the equations for making the correction. If not, I can
work them out for you.

Keep in mind though that the technique of using torque to determine
bolt stretch is by its nature not particularly accurate to begin
with. Unless the offset involved is more than, say, ten percent
of the effective length of the torque wrench (not the case with
most crowfoot types) I wouldn't be too concerned about calculating
the correction.

Eric T.     '86 5kS
erict@ra.cta.com