What is the hardness of metal material HRF? Can it be converted by HRC or HV?

HRF is also a kind of Rockwell hardness, which is used to test pure copper, soft copper alloy and hard aluminum alloy.

HRF measurement object is too soft to use HRC or HV ~

Rockwell hardness includes HRA, HRB, HRC, HRF, HRG and HRR.