Rockwell Hardness Tester Instruction and Operation video, for Phase II model 900-331 and 900-331D Rockwell Hardness Testers. This IS the Industry STANDARD, for Rockwell Hardness Testing. Designed for hardness testing on metal parts, in standard rockwell scales such as HRC, HRB, HRA, HRE and HRF. The most popular Rockwell Hardness Tester in the market today.
