These two choices for bore measurement come into play when close tolerances are the order of the day and speedy, repeatable measurements are required in a production environment. Keeping these requirements in mind, instrument makers usually offer options such as hard chromed bodies or carbide pads and contacts where needed to keep wear at a minimum.
Any article on dimensional measurement will usually get around to micrometers in one form or another. This series on bore measurement is no exception even though I am only offering a brief look at the application.
In my last column I beat up on the calibration of adjustable thread ring gages. Since I’m a nice guy, I thought it only fair that non-adjustable or solid thread ring gage calibration get similar treatment.
This question is prompted by another round-robin type study involving the calibration of thread plug gages, the results of which were predictable because similar studies over the past twenty years or so have produced similar results.