A quick guide on how to read a micrometer screw gauge.Similar to the way a vernier caliper is read, a micrometer reading contains two parts. the first part is contributed by the main scale on the sleeve; the second part is contributed by the rotating vernier scale on the thimble O.K. so now we know how to read a micrometer! We just need some practice. In the picture below, the Sleeve shows 3 dollars and one quarter (25 cents). The Thimble shows one penny. To calculate this reading we add 3 dollars plus 1 quarter plus 1 penny. The actual measurement is.326 inches. Do you know how to read a micrometer? Have you ever had a use for one? Learn what a micrometer is and how one might benefit you. Basic Micrometer Movement The illustration above shows a basic micrometer movement as used on outside and inside micrometers. The thimble rotates relative the barrel on a threaded shaft that has 40 threads per inch. Therefore one complete revolution of the thimble moves it axially 1/40th, or.025 inch. How to Read A Micrometer. May 19, 2019 February 10, 2019 by miftahabibi. After you learn how to use the micrometer, the next basic is how to read the micrometer or taking the reading. The unit system that’s used in micrometers has two versions. This video continues the series on using precision measuring tools that are used by the mechanic. The detailed video uses closeup video to show hoe standard micrometers are used. How to Read A Micrometer. Leave a Comment Cancel reply. Comment. Name Email Website. Created by someone who majors in Electronic Instrument, we intend to provide helpful content for those who are interested in measuring instruments, especially those who want to buy their new one. Recent Posts. How to read a micrometer graduated in 0.001 Micrometer thimble showing 0.276 inch In the picture above, the thimble is positioned to where it is setting between the 2nd and 3rd numbered graduation thus 2 x 0.100” = 0.200”. Past that there are three additional sub-divisions, which is 3 x.025” = 0.075”. How to Use and Read an Outside Micrometer. If you are a machinist, manufacturing, or engine professional, exact measurements are an everyday must. When it comes to measuring cylindrical or spherical objects, an outside micrometer would be.