2" - 6" Dial Bore Gage Set with Hardened Anvils

Why a dial bore gage? A dial bore gage is one of the most accurate tools for measuring a cylindrical bore, or for checking a bore for out-of-roundness or taper. The dial bore gage does not give a direct measurement; it gives the amount of deviation from a preset size, or the amount of deviation from one part of the bore to another. A master ring gage, an outside micrometer, or a caliper can be used to preset the gage. A dial bore gage has two stationary spring-loaded points and an adjustable point to permit a variation in range. These three points are evenly spaced to allow accurate centering of the tool in the bore. A fourth point, the tip of the dial indicator, is located between the two stationary points. By simply rocking the tool in the bore, the amount of variation on the dial can be observed.