Starrett 436.1RL-4 Outside Micrometre, Ratchet Stop, Lock Nut, 3-4" Range, 0.001" Graduation, +/-0.00015" Accuracy

The Starrett 436.1 series outside micrometre has a Vernier scale in inch units for taking precise outside diameter (OD) measurements, a tapered frame for measuring narrow slots and tight places, and a ratchet-stop mechanism that helps provide uniform pressure for precise, repeatable measurements. The micrometre's steel frame has a baked enamel finish for protection and durability. The Vernier scale on the thimble and sleeve is graduated to 0.001”, with a satin chrome rust- and glare-resistant finish. The spindle and anvil have flat, micro-lapped steel measuring faces for accuracy. A knurled ring-type lock nut helps provide secure locking of the measurement position. Micrometres 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. Micrometres are typically used in manufacturing, machining, and mechanical engineering. There are three types of micrometre: outside, inside, and depth. Outside micrometres may also be called micrometre callipers, and are used to measure the length, width, or outside diameter of an object. Inside micrometres are typically used to measure interior diameter, as in a hole. Depth micrometres 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.