[nuancebydefault]

You don't need to flex the material you are measuring to get tens of microns difference. Simply both sides of the caliper will not stay parallel since there is always some dust or fluid between the sliding pieces. The dust will simply flex.

[rowanG077]

Of course. To get a good reading you have to clean both surfaces. I mean if you want to wring blocks together it won't work without clean surfaces either.