Hardness converter is an app that allows you to convert the values of all the existing scales of hardness according to ASTM E140-07:
Rockwell (A, B, C, D, 15N, 30N, 45N)
Also converts the hardness values in unit loads strength(tensile strength Rm [N/mm2])
The application is also fine a theoretical guide that allows the user to want to learn more about the hardness scales and how to run the test.
This application is easy to use and above all free.