Metric Measuring
Metric Measuring
Standard Unit: 1 millimeter (mm) which is equal to about .040".
Metric Micrometer
Micrometer Sleeve (Fixed scale)
Each major line = 1.0 mm
Each minor line = .5 mm
Micrometer thimble (rotating scale)
The thimble rotates .5 mm per revolution and therefore contains 50 lines of .01 mm each.
Some metric micrometers will have 1/2 divisions which represent .005 mm and allow the micrometer to read to the five-thousandths of a mm.
Reading the metric micrometer
1. Note the whole nearest millimeter (if more than 1 mm) on the sleeve and record.
Example: 5.
2. Note the one-half millimeter mark (if appropriate) and record.
Example: 5.5
3. Read the closest hundredth on the thimble and add to the total.
Example: 5.5 + .25 = 5.75
Review of example
Whole mm 5. mm
Half mm .5 mm
Hundredth mm .25 mm
Total 5.75 mm