Mitutoyo 511-303 Bore Gage, 250-400mm Range, +/- 5 Micrometer Accuracy

The Mitutoyo 511-303 bore gage has a measurement range of 250 to 400 mm, with + or - 5 micrometers of accuracy. The micrometer head travels 50 mm, and the probe depth is 250 mm. There are two 50 mm anvil extensions for the micrometer head. These interchangeable anvils attach to the micrometer head for accurate dimensional setting, and to expand the measurement range.

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 the measurement through a vernier, dial, or digital display. Bore gages have a two- or three-point contact, which indicates how many points on the gage 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 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 511-303 bore gage
• Two 50 mm anvils