The Starrett 485M series V-Anvil micrometer has a V-anvil for direct outside diameter (OD) measurement of three-fluted or five-fluted taps, milling cutters, reamers, or out-of-roundness. It also has a vernier scale in inch units for taking precise outside diameter (OD) measurements, and a ratchet-stop mechanism that helps provide uniform pressure for precise, repeatable measurements. The micrometer is made of high-grade tool steel for durability with a satin chrome rust- and glare-resistant finish. The vernier scale on the thimble and sleeve is graduated to 0.001”. The spindle and anvil have micro-lapped measuring faces for accuracy and are carbide-tipped for wear resistance. A knurled ring-type lock nut helps provide secure locking of the measurement position.
Micrometers are precision measuring instruments that use a calibrated screw to measure small 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.