The Rockwell Hardness Test presses a steel or diamond hemisphere-conical penetrator against a test specimen and measures the resulting indentation depth as a gage of the specimen hardness. The harder the material, the higher the HR reading. In the test, a minor load (10 kgf) is first applie...
HRA 75 Rockwell A-Scale 59~86 HRB >> Rockwell B-Scale 41~100 HRC 48 Rockwell C-Scale 19~69 HRD 62 Rockwell D-Scale 39~77 HRF >> Rockwell F-Scale 88~100 HR-15N 85 Rockwell Superficial 15N 69~94 HR-15T >> Rockwell Superficial 15T 77~93 HR-30N 67 Rockwell Superficial...