Torque wrench settings?

Why do manufacturers specify a (biggish) range of torque settings?
Wouldn't one suffice?
Bummers

 

1. calibration of torque wrenches varies
2. friction between fastener and hole varies (affecting "felt" torque vs
"applied" torque)
2 is the result of:
a) fastener type
b) fastener quality
c) contamination (e.g. with lubricants, abrasives, etc.)
d)etc.

Unless the application is critical, you specify a range that works, and
design a fair margin of error into the components. If the application is
critical, you start to see torque-to-yeild fasteners or the work gets
taken out of the hands of people outside of specialist houses.

--
Later,
John



'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.