Selecting an Outside Micrometer on Amazon.com
An outside micrometer uses a screw mechanism to precisely measure the outside dimensions of an object with accuracy possible to .0001" or less. It is used for a variety of applications where precise measurements are necessary, such as machining and engineering. Outside micrometers vary in their display type and their style of anvil and spindle. Readings may be taken from a vernier scale, dial, mechanical digit counter, LCD, or a combination of these. The spindle and anvil are the two measuring faces of the outside micrometer. The standard spindle and anvil faces are flat, but specialized shapes are available to measure round objects, gear teeth, V-shaped cutting heads, and other challenging surfaces. Micrometers differ from calipers, which measure using a pivot point or slide mechanism instead of the micrometer's screw mechanism. Other types are inside micrometers that measure interior diameter and depth micrometers that measure depth of grooves or steps.