The World's Largest Online Measuring Instrument Store!
Providing OEM, Wholesale and Retail Services Worldwide. Toll Free :
1-800-717-5818 (U.S. )
Home > Education >Micrometer Information

Typical procedure for reading a micrometer

?Tools required to perform this task are a micrometer set and a clean shop towel.
?Select the correct micrometer. If the component measurement is less than 1 inch, use the 0-to-1 inch micrometer.
?Check the calibration of the micrometer.
?Locate the component between the anvil and spindle of the micrometer, and rotate the thimble to slowly close the micrometer around the component. Tighten the thimble until a slight drag is felt when passing the component in and out of the micrometer. If the micrometer is equipped with a ratchet, it can be used to assist in maintaining proper tension.
?Lock the spindle to prevent the reading from changing.
?Remove the mocrometer from the component.
?Each number on the sleeve is 0.100 inch, and each graduation represents 0.025 inch. To read a measurement, count the visible lines on the sleeve.
?The graduations on the thimble define the area between the lines on the sleeve on 0.001 increments. To read this measurement, use the graduation mark that aligns with the horizontal line on the sleeve.
?Add the reading obtained from the thimble to the reading on the sleeve to get the total measurement.
?Since the 0 on the thimble scale aligns on the reading line and the last sleeve graduation is 5, the reading is 0.500 inch.
?If graduation marks are visible after a number on the sleeve scale, add the graduation value to the number in this case, the micrometer reads 0.375 inch.
?Use the thimble scale to determine the thousandths to the sleeve scale. This micromter is reading 0.311 inch.
?Some micrometers have vernier scales that allow ten-thousandths-inch readings. The 2 on the vernier scale is the only one that aligns with a thimble graduation mark. The reading is 0.3112 inch.