On Jul 16, 11:18*pm, wrote:
...
I think up to ~80% of the tightening force on a screw can be lost to
friction. Compare the torque to tighten with that to loosen.

I guess they are different :-) ??
...
Michael Koblic,
Campbell River, BC-

Not by much sometimes. AFAIK the torque to loosen is mainly from
friction. In a simple system like sliding a load up a ramp the force
going up is the friction + the load, going down it's the friction -
the load.

My 10,000 # load cell is a pressure gage on a cylinder like this:
http://www.harborfreight.com/10-ton-...ram-95979.html

You might find a spring scale for weighing fish/deer/moose in a
sporting goods store.
http://www.harborfreight.com/hand-he...ale-97227.html

jsw