Review on Starrett 247D Micrometer Attachments Diameter by Nale Dunn

The Starrett Micrometer Attachment is the perfect accessory as it is a lot cheaper (<$12) than buying a micrometer with a spherical or interchangeable anvil. I find it particularly useful when I need to measure the thickness of curved features like bearing shells and tube walls. This ball mount is fairly easy to install as it simply slides over the flat anvil on the micrometer body and is held firmly in place with a collet. The only downside is that the user has to remember to subtract the diameter of the ball (0.200") from the displayed reading. There are several different models of this nozzle, each sized to correspond to the specific micrometer model you have.