Establishment of traceability in hardness measurement is still under discussion at the ISO TC 164 SC 3 subcommittee on hardness testing. Two paths for establishing traceability are proposed for the Rockwell hardness measurement in ISO 6508-1. One way is taking a route to SI units through direct calibration of machine components, and the other way is taking a route to a hardness measurement standard through indirect calibration of machine performance. In addition to this, the difference in hardness measurement procedures between Rockwell and Brinell/Vickers hardness causes further confusion in establishing a traceability chain and an uncertainty evaluation process. This confusion is partly caused by the characteristics of hardness value, i.e. a procedure-dependent property. In this paper, methods used for the establishment of traceability for Rockwell, Brinell and Vickers hardness measurements are discussed based on the concept defined in the VIM.