Hardnester(YAMAMOTO)

Hardnester for general use for precision tools
Rockwell "C" 8 Hardness Set Vickers 8 Hardness Set Vickers 16 Hardness Set
No. Ⅰ HRC 20 HV 200 HV 200-250
No. Ⅱ HRC 30 HV 300 HV 300-350
No. Ⅲ HRC 40 HV 400 HV 400-450
No. Ⅳ HRC 50 HV 500 HV 500-550
No. Ⅴ HRC 55 HV 600 HV 600-650
No. Ⅵ HRC 60 HV 700 HV 700-750
No. Ⅶ HRC 65 HV 800 HV 800-850
No. Ⅷ HRC 67 HV 900 HV 900-950