Rockwell Hardness Number | Rockwell Superficial Hardness Number | |||
C Scale, 150-kgf Diamond Penetrator (HRC) |
A Scale, 60-kgf Diamond Penetrator (HRA) |
15-N Scale, 15 kgf Superficial Diamond Penetrator (HR 15-N) |
30-N Scale, 30-kgf Superficial Diamond Penetrator (HR 30-N) | 45-N Scale, 45-kgf Superficial Diamond Penetrator (HR 45-N) |
48.00 | 74.40 | 84.10 | 66.20 | 52.10 |
47.00 | 73.90 | 83.60 | 65.30 | 50.90 |
46.00 | 73.40 | 83.10 | 64.50 | 49.80 |
45.00 | 72.90 | 82.60 | 63.60 | 48.70 |
44.00 | 72.40 | 82.10 | 62.70 | 47.50 |
43.00 | 71.90 | 81.60 | 61.80 | 46.40 |
42.00 | 71.40 | 81.00 | 61.00 | 45.20 |
41.00 | 70.90 | 80.50 | 60.10 | 44.10 |
40.00 | 70.40 | 80.00 | 59.20 | 43.00 |
39.00 | 69.90 | 79.50 | 58.40 | 41.80 |
38.00 | 69.30 | 79.00 | 57.50 | 40.70 |
37.00 | 68.80 | 78.50 | 56.60 | 39.60 |
36.00 | 68.30 | 78.00 | 55.70 | 38.40 |
35.00 | 67.80 | 77.50 | 54.90 | 37.30 |
34.00 | 67.30 | 77.00 | 54.00 | 36.10 |
33.00 | 66.80 | 76.50 | 53.10 | 35.00 |
32.00 | 66.30 | 75.90 | 52.30 | 33.90 |
31.00 | 65.80 | 75.40 | 51.40 | 32.70 |
30.00 | 65.30 | 74.90 | 50.50 | 31.60 |
29.00 | 64.80 | 74.40 | 49.60 | 30.40 |
28.00 | 64.30 | 73.90 | 48.80 | 29.30 |
27.00 | 63.80 | 73.40 | 47.90 | 28.20 |
26.00 | 63.30 | 72.90 | 47.00 | 27.00 |
25.00 | 62.80 | 72.40 | 46.20 | 25.90 |
24.00 | 62.30 | 71.90 | 45.30 | 24.80 |
23.00 | 61.80 | 71.30 | 44.40 | 23.60 |
22.00 | 61.30 | 70.80 | 43.50 | 22.50 |
21.00 | 60.80 | 70.30 | 42.70 | 21.30 |
20.00 | 60.30 | 69.80 | 41.80 | 20.20 |
Rockwell Hardness Number | Rockwell Superficial Hardness Number | |||
B Scale, 100-kgf 1/16 in (1.588mm) ball (HRB) |
A Scale, 60-kgf Diamond Penetrator (HRA) |
15-T Scale, 15 kgf 1/16 in (1.588 mm) ball (HR 15-T) |
30-T Scale, 30-kgf 1/16 in (1.588mm) ball (HR 30-T) |
45-T Scale, 45-kgf 1/16 in (1.588mm) ball (HR 45-T) |
100 | 61.5 | 91.5 | 80.4 | 70.2 |
99 | 60.9 | 91.2 | 79.7 | 69.2 |
98 | 60.3 | 90.8 | 79.0 | 68.2 |
97 | 59.7 | 90.4 | 78.3 | 67.2 |
96 | 59.1 | 90.1 | 77.7 | 66.1 |
95 | 58.5 | 89.7 | 77.0 | 65.1 |
94 | 58.0 | 89.3 | 76.3 | 64.1 |
93 | 57.4 | 88.9 | 75.6 | 62.1 |
92 | 56.8 | 88.6 | 74.9 | 62.1 |
91 | 56.2 | 88.2 | 74.2 | 61.1 |
90 | 55.6 | 87.8 | 73.5 | 60.1 |
89 | 55.0 | 87.5 | 72.8 | 59.0 |
88 | 54.5 | 87.1 | 72.1 | 58.0 |
87 | 53.9 | 86.7 | 71.4 | 57.0 |
86 | 53.3 | 86.4 | 70.7 | 56.0 |
85 | 52.7 | 86.0 | 70.0 | 55.0 |
84 | 52.1 | 85.6 | 69.3 | 54.0 |
83 | 51.5 | 85.2 | 68.6 | 52.9 |
82 | 50.9 | 84.9 | 67.9 | 51.9 |
81 | 50.4 | 84.5 | 67.2 | 50.9 |
80 | 49.8 | 84.1 | 66.5 | 49.9 |
79 | 49.2 | 83.8 | 65.8 | 48.9 |
78 | 48.6 | 83.4 | 65.1 | 47.9 |
77 | 48.0 | 83.0 | 64.4 | 46.8 |
76 | 47.4 | 82.6 | 63.7 | 45.8 |
75 | 46.9 | 82.3 | 63.0 | 44.8 |
74 | 46.3 | 81.9 | 62.4 | 43.8 |
73 | 45.7 | 81.5 | 61.7 | 42.6 |
72 | 45.1 | 81.2 | 61.0 | 41.8 |
71 | 44.5 | 80.8 | 60.3 | 40.7 |
70 | 43.9 | 80.4 | 59.6 | 39.7 |
69 | 43.3 | 80.1 | 58.9 | 38.7 |
68 | 42.8 | 79.7 | 58.2 | 37.7 |
67 | 42.2 | 79.3 | 57.5 | 36.7 |
66 | 41.6 | 78.9 | 56.8 | 35.7 |
65 | 41.0 | 78.6 | 56.1 | 34.7 |
64 | 40.4 | 78.2 | 55.4 | 33.6 |
63 | 39.8 | 77.8 | 54.7 | 32.6 |
62 | 39.3 | 77.5 | 54.0 | 31.6 |
61 | 38.7 | 77.1 | 53.3 | 30.6 |
60 | 38.1 | 76.7 | 52.6 | 29.6 |