The Starrett 701 series internal groove vernier inside micrometer has caliper-type jaws with flush-ended contacts for measurement of grooves inside rings, bores, and tubes, and a vernier scale in inch units for taking precise inside dimension (ID) measurements. The micrometer is made of high-grade tool steel, with hardened and ground flush-ended gauging contacts that help gauge grooves at the bottom of blind holes. A knurled friction thimble helps provide quick adjustment capability. The vernier scale is graduated to 0.001” and a locking clamp helps hold measurements in place. The micrometer has 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.