Measurement of Hardness
Throughout this experiment, hardness measurements will be made using a Rockwell
hardness tester. A 1/16" steel ball indentor with either a 60 or 100 kg load corresponds to the
Rockwell F or Rockwell B scales. Hardness value may be calculated from the load applied
divided by the surface area of the indentation. However, the instrument you will use is
calibrated to read hardness values directly. Consult with the instructor before operating the
hardness tester. You should run a hardness test on the test standard for the particular scale
being used before and after each set of measurements. At least three hardness measurements
should be made on a smooth surface of each specimen to achieve statistical significance. If your
hardness values fall below 20 or above 100, you need to change hardness scales