The Starrett 124DZ solid-rod inside micrometer set includes two micrometer heads, each graduated to 0.001”, a set of ten interchangeable and adjustable measuring rods, and four spacing collars that can be used in combination to span from 2 to 32”. These micrometers are designed for measuring the inside diameters of large cylinders, rings, and parallel surfaces. The micrometer set comes with wrenches for making needed adjustments and a protective wood case for storage.

The micrometer’s measuring rods are marked with their length range, and have adjustable anvils that are hardened and ground for accuracy. The rods are made of solid steel for lightness and rigidity, are insulated to prevent heat expansion when held in the hand, and have a rust-resistant, satin chrome finish. Rods adjustable to 8” in length are 0.25” (6mm) in diameter with a compatible 0.5” spacing collar, while rods adjustable from 8” and greater are 11/32” (8.5 mm) in diameter with compatible 1” and 2” spacing collars. Rods adjustable to 8” attach to the micrometer head with a screw movement of 0.5” for each full turn, while rods adjustable from 8” and greater attach to the micrometer head with a screw movement of 1” for each full turn. All rods attach to the micrometer heads by a locking shoulder that grips the rod securely into place. Both micrometer heads have a knurled friction thimble that supports adjustment with uniform pressure, quick-reading graduations to 0.001”, and a rust-resistant, glare-free, satin chrome finish.

Micrometers are precision measuring instruments that use a calibrated screw to measure distances. These measurements are translated into large rotations of the screw that are then able to be read from a scale or a dial. Micrometers are typically used in manufacturing, machining, and mechanical engineering. There are three types of micrometer: outside, inside, and depth. Outside micrometers may also be called micrometer calipers, and are used to measure the length, width, or outside diameter of an object. Inside micrometers are typically used to measure interior diameter, as in a hole. Depth micrometers measure the height, or depth, of any shape that has a step, groove, or slot.

The L.S. Starrett Company manufactures precision measuring tools, metrology and testing equipment, and saw blade products. The company was founded in 1880 and is headquartered in Athol, MA.

What’s in the Box?

• Starrett H124A/B micrometer head
• Starrett H124C micrometer head
• 2” measuring rod
• 3 to 4” adjustable measuring rod
• 4 to 5” adjustable measuring rod
• 5 to 6” adjustable measuring rod
• 3 to 7” adjustable measuring rod
• 7 to 8” adjustable measuring rod
• 8 to 14” adjustable measuring rod
• 14 to 20” adjustable measuring rod
• 20 to 36” adjustable measuring rod
• 26 to 32” adjustable measuring rod
• 0.5” spacing collar
• 1” spacing collar
• Two 2” spacing collars
• Three wrenches
• Fitted case