In article ,
(DoN. Nichols) wrote:

In article ,
Don Bruder wrote:

[ ... Rockwell hardness tester operation ... ]

First off, just to be clear, I ain't the OP, just an interested
bystander with an observation/query about the item in question.

Correct me if I'm getting things cock-eyed, but...

This gizmo sounds to me like it's essentially a concept of "put in a
sample, work the lever to put a (presumably calibrated) amount of force
behind a hard (diamond?) point, then measure how deep the resulting dent
is and convert the depth to a rockwell number." Correct? Incorrect?
Somewhere in between?

Close -- with the addition of "first apply minor preload force
(with the vertical positioning screw) to set the zero, then work the
lever to apply gently apply the greater force, and return the lever to
remove the greater force, so you can measure how much deeper the diamond
is after the extra force.

Mi capiche. I simply forgot to include the "zero" step as I was typing.

I say this 'cause the discussion on preloading and zeroing the dials
sounds *A WHOLE BUNCH* like the setup for measuring runout on a shaft,
or brake rotor, or similar, using a machinist's dial indicator.

Similar -- except that the dial indicator is not intended to
deform the DUT (Device Under Test) in your shaft or brake rotor checking.

Right, but that wasn't the point - The post I was responding to made it
sound a *WHOLE LOT* like setup/use of a dial-indicator for runout
checking. I'm quite aware that the indicator doesn't dent the test item,
or even make an attempt to.

The "sounds like using a dial indicator" idea sparked a train of thought
that derailed into how the hardness tester might be generating its
reading, causing a major spill of "I think it might work like this,
let's ask and see if I'm crazy, brilliant, or somewhere in between"

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