General
Information
1‐21
When reading a metric micrometer, add
the number of millimeters and half-
millimeters on the sleeve line to the
number of one one-hundredth
millimeters on the thimble. Perform the
following steps while referring to
Figure
25.
Read the upper half of the sleeve line
and count the number of lines visible.
See if the half millimeter line is visible on
the lower sleeve line. If so, add 0.50mm
to the reading in step 1
Read the thimble mark that aligns with
the sleeve line. Each thimble mark
equals 0.01mm.
Add the readings from steps 1-3.
Standard Inch
Micrometer
The standard inch micrometer (Figure
26) is accurate to one-thousandth of an
inch or 0.001. The sleeve is marked in
1.25
in. increments. Every fourth
sleeve mark is numbered
1,2,3,4,5,6,7,8,9. These numbers
indicate 0.100, 0.200, 0.300, and so on.
The tapered end of the thimble has 25
lines marked around it. Each mark
equals 0.001 in. One complete turn of
the thimble will align its zero mark with
the first mark on the sleeve or 0.025 in.
To read a standard inch micrometer,
perform the following steps and refer to
Figure 27.
1.
Read the sleeve and find the
largest number.