Mitutoyo HM-200A Series - Page 147

9. Appendix
No. 99MBG127A
9-9
ASTM soft (ASTM E 140, for soft steel (non-austenitic steels),
HRB to others hardness conversion chart), continued
HRB HV
HBS
29421N
HK
4.9035N,
and Over
HRA HRF HR15T HR30T HR45T
49 106 34.6 84.8 76.6 49.0 21.7
48 105 34.1 84.3 76.2 48.3 20.7
47 104 33.7 83.7 75.9 47.7 19.7
46 103 33.3 83.1 75.6 47.0 18.7
45 102 32.9 82.6 75.3 46.3 17.7
44 101 32.4 82.0 74.9 45.7 16.7
43 100 32.0 81.4 74.6 45.0 15.7
42 99 31.6 80.8 74.3 44.3 14.7
41 98 31.2 80.3 74.0 43.7 13.6
40 97 30.7 79.7 73.6 43.0 12.6
39 96 30.3 79.1 73.3 42.3 11.6
38 95 29.9 78.6 73.0 41.6 10.6
37 94 29.5 78.0 72.7 41.0 9.6
36 93 29.1 77.4 72.3 40.3 8.6
35 92 28.7 76.9 72.0 39.6 7.6
34 91 28.2 76.3 71.7 39.0 6.6
33 90 27.8 75.7 71.4 38.3 5.6
32 89 27.4 75.2 71.0 37.6 4.6
31 88 27.0 74.6 70.7 37.0 3.6
30 87 26.6 74.0 70.4 36.3 2.6