Includes three graphical charts intended to provide a basis for conversion when making comparisons between the Diamond Pyramid, Brinell, and Rockwell hardness scales. The charts apply only to carbon and alloy constructional steels, and tool steels in all conditions other than the cold worked. Provision is made in each chart for a scatter band about the centre line. The Standard includes explanatory matter related to limitations on conversion of hardness values, the use of the charts, and reporting converted hardness numbers.