"Wes" wrote in message
news
"N_Cook" wrote:

Is the torque release clutch there to make sure it is impossible to strain
the mechanism by over tightening or is it to give results that are
repeatable if used by different people. ie below the torque release force
is
the area where grime/gummy lubricant etc would give inconsistent results
if
measurement was by feel of "first" touch.

It is never impossible, heck, they can drop it. It is an attempt to
mechanically put
'feel' into the mic.

I haven't checked but if the user spins the mic closed on part being
measured, I'm sure
they can get a different reading regardless of any ratchet or friction
system. Inertia
you know.

Wes

A couple of the old timers I knew in the business, at Mitutoyo and Starrett,
didn't disguise their disdain for relying on ratchet thimbles. The general
opinion was that three different inexperienced users, all using the same
ratchet mike, would get three different readings off of the same part.

You still need some practice with the things to get consistent results.

--
Ed Huntress