Abstract: Applicant has disclosed a chamfer gage with interchangeable anvil assemblies which can measure the diameter of chamfered holes and the chamfer angle (up to 135°). In the preferred embodiment, the chamfer gage comprises: an indicator housing; a compression fitting, attached to the housing, for securing an indicator spindle for movement inside the housing; and an interchangeable anvil assembly, having an anvil body with a depressible anvil or plunger inside, which can be detachably connected to the indicator housing by a threaded thumb ring rotatably mounted on the housing. Another interchangeable anvil assembly can be swapped within thirty seconds to measure the chamfer of a different hole size.

Abstract: A gage master artifact and method for verifying calibration of machine tools and other positioning apparatus such as a coordinate measuring machine wherein measurements are taken of bore sizes and lengths of the artifact in different orientations within the coordinate field of the apparatus by a probe of that apparatus and comparing such measurements with known measurements of the artifact to verify calibration accuracy of the apparatus.