The Starrett 124 Solid-Rod Inside Micrometer Sets are the most popular inside micrometers because of their lightness, ease-of-use and range. They are very useful for measuring the inside diameters of cylinders and rings and measuring parallel surfaces.
The desired range is obtained by assembling rods and spacing collars to the micrometer head. Measuring rods are provided with a shoulder that is set accurately in the micrometer head and locked in position. When assembling rods to the A and B heads, the reading line on the micrometer head should be lined up with the marking on each rod (except for the 50-75mm (2-3″”) rods).
Rod diameters are approximately 6mm (1/4″”) on the A and B sizes, and approximately 8.5mm (11/32″”) on the C size. Each rod has individual length adjustment for the anvil by means of special wrenches furnished.

• Measuring rods are solid and assembled on one side of the micrometer head
• Insulated rods marked with length
• Hardened and ground anvils on rods, adjustable for length
• Head anvil is hardened and ground
• Quick-reading figures ? every thousandth numbered on inch reading tools
• Convenient handle is available to provide reach for use in deep holes. Handle screws into the micrometer head in place of the dummy screw, which is opposite a rod lock screw. Distance from the end of the handle to the centre line is 158mm (6-1/4″)
• Type: Inside Micrometer Set
• Range: 50-200mm
• Graduations: .01mm
• Measuring Rods (qty): Six
• Spacing Collars: One 12mm
• Accuracy: Lead accuracy +/-.003mm per 25mm
• Packaging: Padded case