Proudly launches an outside micrometer made of cast steel with chrome-plated head assembly. The least-count is 0.01mm. The External Micrometer is used to check the thickness of any part. It is very useful in workshops, tool-rooms, and inspection labs. Each micrometer is packed in a plastic case with a master gauge and adjustment spanner. Each Micrometer comes with a Calibration Certificate. Outside Micrometers are used for measuring the thickness or outside diameter of small parts. ... To ensure an accurate measurement, the measuring faces of a micrometer must be both flat and parallel. Micrometer measuring faces (anvil and spindle) are normally faced with carbide to reduce the wear caused by repeated use. To read the micrometer in thousandths, multiply the number of vertical divisions visible on the sleeve by 0.025", and to this add the number of thousandths indicated by the line on the thimble which best coincides with the central long line on the sleeve.