Starrett 575AP Screw Thread Micrometre, Plain Thimble, 7-9 Threads/Inch Range, 0.001" Graduation, 0-1" Pitch Dia.

The Starrett 575/585 series outside micrometer has a V-anvil and conical spindle for measuring pitch diameters of screw threads, a tapered frame for measuring narrow slots and tight spaces and a vernier scale in inch units for taking precise outside diameter (OD) measurements. The vernier scale on the thimble and sleeve is graduated to 0.001”. The micrometer is made of high-grade tool steel with a satin chrome rust- and glare-resistant finish. 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. 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.