The unit of hardness given by the test is known as the Vickers Pyramid Number (HV) or Diamond Pyramid Hardness (DPH).The hardness number can be converted into units of pascals, but should not be confused with pressure, which also has units of pascals.The hardness number is determined by the load over the surface area of the indentation and not the area normal to the force, and is therefore not pressure.ickers hardness numbers are reported as xxxHVyy, e.g. 440HV30, or xxxHVyy/zz if duration of force differs from 10 s to 15 s, e.g. 440Hv30/20, where: 1  440 is the hardness number, 2  HV gives the hardness scale (Vickers), 3  30 indicates the load used in kgf.