Question

what are the precautions to be taken before using screwguage​

Answer 1

Answer:

Precautions

There shouldn't be any friction while moving the screw.

The screw should always be rotated by ratchet R and not by cap K to avoid undue pressure.

For zero correction proper sing should be noted.

To avoid back-lash error in the screw, the screw should be moved in the same direction.