The lock nut is simply a quarter turn nut that locks the spindle from turning. The sleeve contains the scale which is used to determine the measurement and the internal threads which allow the spindle to move.
20) Lock nut in the micrometer is provided to
Lock the reading after setting it over the workpiece
Related Measuring MCQ - Machinist(Set-1) with Answers
Nut & bolt
The working principle of the Micrometer is based on screw and nut. (Rotational moment to linear moment) As we know as the screw rotates one revolution on the screw, then the screw moves linearly by one pitch distance
Vernier bevel protractor
Vernier bevel protractor is used to accurately measure the angle of taper
Least count of Vernier Caliper is 0.02 mm
Rack and pinion mechanism
The dial test indicator or dial gauge amplifies the length or displacement and translate it into rotational motion of pointer over a circular scale using Rack and Pinion Mechanism. It is used for pointer over a circular scale.