The Mitutoyo 515-590 bore gage zero checker allows zero adjustment of dial bore gages with a range of 18 mm (0.7") through 400 mm (16") using gage blocks (sold separately). It checks zero point for measurement quality assurance. The flatness of the parallel jaws is 0.5 micrometers, and the parallelism of the parallel jaws is 1 micrometer. The set includes a stand, three attachments, and two dedicated jaws.

Bore gages 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 gages are typically calibrated with a setting ring. Bore gages come in two types, one simple, and the other direct-measuring. Simple bore gages are used with a caliper to transfer the hole measurement, while the more complex gages take the measurement directly, and display it through a vernier, dial, or digital display. Bore gages have a two- or three-point contact, indicating how many points on the gage head touch the inside of the bore. Two-point contacts are better at measuring ovality, while three-point contacts are used to measure lobing or triangular form error. Pistol-grip bore gages are used for fast, single-handed operation with good repeatability from one operator to another. Bore gages, regardless of type, can be used in some special applications, such as measuring threads, spline pitch diameters, and deep bores.

Mitutoyo manufactures precision measuring tools, metrology equipment, and systems. The company was founded in Tokyo in 1934 and formed Mitutoyo America Corporation in 1963, which is headquartered in Aurora, IL.

What€s in the Box?

• Mitutoyo 515-590 zero checker stand
• Three attachments
• Two dedicated jaws