Volume 16, Issue 4 (July 1988)
Measurement of the Spherical Tip of Rockwell Indenters
Recent international comparisons of primary standards of Rockwell C hardness showed that the indenter shape is largely responsible for differences in measurement results. Measurements, especially of spherical-tip shape, made by means of high-magnification (500 ×) profile projectors proved to be affected by an uncertainty that also depended on the operator. In connection with such problems, a measurement system using a rotating table centered by means of an air bearing was developed together with a method for result analysis so as to allow the evaluations required by ASTM and ISO standards to be made quickly.