How to Read a Metric Micrometer

If you said 12 mm, you were right! Let’s try another one to be sure you’ve got it.  Remember, you can click the picture to get a better view.

do you see 14mm?  Good.  Let’s move on.  Remember that the barrel scale shows both whole and half millimeters? Take a look at the reading below to see if you understand how that works.

Did you say 11.5?  See how there is a half mark showing?  Great! You’ve got the barrel scale down.

Remember that we said this micrometer would measure down to the nearest 1/100 the of a millimeter?  We can do this because of the thimble scale.  The thimble scale has fifty marks around it.  It also opens or closes the spindle by one-half millimeter each time it turns around.  This means that each mark on the thimble scale equals 0.01 millimeters (that’s tiny!).  Here is how it looks…

The best way to use the thimble scale is to remember that each mark represents two digits (the tenths and hundredths places).  So look at a number like five as 0.05 , and ten as 0.10. This thimble scale above is reading 0.00   See how the zero lines up with the horizontal line on the barrel?  You read the thimble scale at this line.