When accuracy of 0.01mm is required the micrometer is the most common instrument. The external measuring screw usually has an increment of 0.5mm/revolution. The base scale is on the sleeve and is graduated in
intervals of 0.5mm. On the thimble there are 50 graduation marks which indicate 1/100 value (0.0 mm).

Micrometers also have a friction facility which allows a constant measuring power which is important when measuring 1/100 and 1/1000mm measurements.
There are many different micrometers for different appliances e.g. outer, depth, bore/hole measurements. Further more there are micrometers with different designs for the feeler pin for special purposes.