Chamfer gage
A chamfer gage consists of a plunger and a ratio indicator that measures the biggest diameter in a chamfer hole. Typically consisting of a 3-blade plunger, a chamfer gage can measure angles between 0 and 90 degrees or 91 and 130 degrees. Chamfer gages have a relatively long range of measurement ability and are very versatile. A chamfer gage can also be mastered against any flat surface. When in a dial gage format, they do require that you count the revolutions to determine the reading, and they do not provide quite as good a fit into the bore being measured as do countersink gages.