The Vickers hardness test employs the same principle of hardness testing that is used in the Brinell test. However, instead of a steel ball, a square-based pyramid is used. Although the impression is square instead of round, the method for calculating the Vickers hardness number (usually abbreviated as HV or VHN) is the same as that for the BHN in that the load is divided by the projected area of indentation. Note: The Rockwell hardness test is somewhat similar to the Brinell test in that a steel ball or a conical diamond point is used. However, Instead of measuring the diameter of the impression, the depth of penetration is measured.