Tests metal objects to determine their degree of hardness, using hardness testing equipment: Positions workpiece on anvil of testing machine and turns controls to press steel ball or diamond point against surface of piece or to allow diamond-pointed hammer fall on surface to be tested.
Measures diameter of indentation caused by steel balls, using microscope, or reads scale on test equipment that indicates depth of penetration of ball or diamond point, or calibrated height of hammer rebound. Reads hardness number from calibrated scale on equipment or converts scale reading to hardness number, using formula or conversion chart. Important variables may be indicated by trade names of equipment used. May cut cross section of sample part and examine part under microscope to determine hardness depth.
