Starrett 247D Micrometer Ball Attachments, 0.200" Ball Diameter, .250" Diameter Anvil And Spindle, Inch

• Easily applied by snapping on to end of either anvil or spindle, thus permitting two attachments to be used together
• Balls are hardened, measure 0.200" in diameter and move freely in the retainer, insuring positive contact with anvil and spindle
• The diameters, 0.200" of each ball used must be subtracted from the micrometer reading
• Applied for Nos. 216, 231, 436.1, 733, 734, 1212 and 1230 micrometers, 0.250" diameter anvil and spindle

Starrett outside micrometers and micrometer heads having spindle can be instantly converted for measuring wall thickness of tubing, split and full bearings, sleeves and other parts with rounded surfaces of the ball attachment.