The Mitutoyo 368-993 Holtest Type II three-point internal micrometer set has alloyed-steel points, a measurement range of 50 to 100 mm, and is precise to 0.005 mm, with + or - 3 micrometers of accuracy. Alloyed-steel measuring contact points offer durability, while contact point geometry allows the instrument to measure to the bottom of a blind hole. The ratchet stop offers constant force for repeatability. Includes inspection certificate ensuring that the exact micrometer purchased has met National Institute of Standards and Technology master standards. This gauge set includes four complete display units, two setting rings, an extension rod, and fitted plastic case.
Bore gauges measure holes, or bores, in a workpiece. They can measure the interior diameter of a hole at any depth, while internal micrometers can only measure to the depth of their teeth. Bore gauges are typically calibrated with a setting ring. Bore gauges come in two types, one simple, and the other direct-measuring. Simple bore gauges are used with a caliper to transfer the hole measurement, while the more complex gauges take the measurement directly, and display the measurement through a vernier, dial, or digital display. Bore gauges have a two- or three-point contact, which indicates how many points on the gauge head touch the inside of the bore. Two-point contacts are better at measuring ovality, while three-point systems are used to measure lobing, or triangular form error. Pistol-grip bore gauges are used for fast, single-handed operation with good repeatability from one operator to another. Bore gauges, regardless of type, can be used in some special applications, such as measuring threads, spline pitch diameters, and deep bores.
Included: