To convert the Vickers hardness number to SI units the hardness number in kilograms-force per square millimeter ( kgf / mm?) has to be multiplied with the standard gravity ( 9.806 65 ) to get the hardness in MPa ( N / mm?) and furthermore divided by 1000 to get the hardness in GPa.
12.
To convert the Vickers hardness number to SI units the hardness number in kilograms-force per square millimeter ( kgf / mm?) has to be multiplied with the standard gravity ( 9.806 65 ) to get the hardness in MPa ( N / mm?) and furthermore divided by 1000 to get the hardness in GPa.
13.
A common error is that the above formula to calculate the HV number does not result in a number with the unit Newton per square millimeter ( N / mm2 ), but results directly in the Vickers hardness number ( usually given without units ), which is in fact kilograms-force per square millimeter ( kgf / mm?).