Observations on HF clicker torque wrench


I was asking about the HF clicker torque wrench recently ("Cheap
click-stop torque wrench" - 9/18). I bought one and just tested it,
using a lever & weights:
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The lever is a 1" square tube, with a sawed-off 3/8" socket welded to
one end. The coffee can has lead weights in it. I gradually move the
weight out 'till the wrench clicks, measure between the center of the
socket and the weight-holding wire, and multiply that distance by the
weight.
With the wrench set to 20 ft-lbs, it clicked at a torque of 17.4 ft-lbs.
13% low. Set at 50 ft-lbs, it clicked at 43, 14% low. HF claims
that it's accurate to 4%.
Also interesting is that it has memory. I.e., it acts differently
depending upon what it has just done. E.g., when testing the 20 ft-lb
setting, it clicked when I got the (8.54 lbs) weight out to 22". But if
I then moved the weight back, it would click at shorter distances (lower
torques), until 20-7/8" (16.6 ft-lbs). If I let it sit a bit & started
over, it didn't click until 22" again. It loosens up when it clicks.
I was tempted to test whether this was a matter of the viscosity of its
grease by seeing if temperature affected the click point, but I wasn't
that curious.
I dunno if I should send it back. Maybe my testing is not as accurate
as I think (although there's not that much room for error). I can
pretty easily add 15% to the torque setting (e.g., set it for 23 when I
want 20). Opinions?
Thanks,
Bob
BTW - those of you who noticed that 8.54 lbs x 22" is not 17.4 ft-lbs,
it's because there's also 1.79 ft-lbs of torque from the weight of the bar.
Reply to
Bob Engelhardt
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