BUEHLER®

Load 25gf (0.025kgf)
Diagonal Knoop Hardness Number
(µm) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
58 106 105 105 105 104 104 104 103 103 103
59 102 102 102 101 101 100 100 99.8 99.5 99.1
60 98.8 98.5 98.2 97.8 97.5 97.2 96.9 96.6 96.2 95.9
61 95.6 95.3 95.0 94.7 94.4 94.1 93.8 93.4 93.1 92.8
62 92.5 92.2 92.0 91.7 91.4 91.1 90.8 90.5 90.2 89.9
63 89.6 89.3 89.1 88.8 88.5 88.2 87.9 87.7 87.4 87.1
64 86.9 86.6 86.3 86.0 85.8 85.5 85.2 85.0 84.7 84.5
65 84.2 83.9 83.7 83.4 83.2 82.9 82.7 82.4 82.2 81.9
66 81.7 81.4 81.2 80.9 80.7 80.4 80.2 80.0 79.7 79.5
67 79.2 79.0 78.8 78.5 78.3 78.1 77.8 77.6 77.4 77.2
68 76.9 76.7 76.5 76.3 76.0 75.8 75.6 75.4 75.2 74.9
69 74.7 74.5 74.3 74.1 73.9 73.7 73.4 73.2 73.0 72.8
70 72.6 72.4 72.2 72.0 71.8 71.6 71.4 71.2 71.0 70.8
71 70.6 70.4 70.2 70.0 69.8 69.6 69.4 69.2 69.0 68.8
72 68.6 68.4 68.2 68.1 67.9 67.7 67.5 67.3 67.1 66.9
73 66.8 66.6 66.4 66.2 66.0 65.9 65.7 65.5 65.3 65.1
74 65.0 64.8 64.6 64.4 64.3 64.1 63.9 63.8 63.6 63.4
75 63.2 63.1 62.9 62.7 62.6 62.4 62.2 62.1 61.9 61.8
76 61.6 61.4 61.3 61.1 60.9 60.8 60.6 60.5 60.3 60.2
77 60.0 59.8 59.7 59.5 59.4 59.2 59.1 58.9 58.8 58.6
78 58.5 58.3 58.2 58.0 57.9 57.7 57.6 57.4 57.3 57.1
79 57.0 56.9 56.7 56.6 56.4 56.3 56.1 56.0 55.9 55.7
80 55.6 55.4 55.3 55.2 55.0 54.9 54.8 54.6 54.5 54.4
81 54.2 54.1 54.0 53.8 53.7 53.6 53.4 53.3 53.2 53.0
82 52.9 52.8 52.7 52.5 52.4 52.3 52.1 52.0 51.9 51.8
83 51.6 51.5 51.4 51.3 51.1 51.0 50.9 50.8 50.7 50.5
84 50.4 50.3 50.2 50.1 49.9 49.8 49.7 49.6 49.5 49.4
85 49.2 49.1 49.0 48.9 48.8 48.7 48.6 48.4 48.3 48.2
86 48.1 48.0 47.9 47.8 47.7 47.5 47.4 47.3 47.2 47.1
87 47.0 46.9 46.8 46.7 46.6 46.5 46.4 46.3 46.1 46.0
88 45.9 45.8 45.7 45.6 45.5 45.4 45.3 45.2 45.1 45.0
89 44.9 44.8 44.7 44.6 44.5 44.4 44.3 44.2 44.1 44.0
90 43.9 43.8 43.7 43.6 43.5 43.4 43.3 43.2 43.1 43.1
91 43.0 42.9 42.8 42.7 42.6 42.5 42.4 42.3 42.2 42.1
92 42.0 41.9 41.8 41.8 41.7 41.6 41.5 41.4 41.3 41.2
93 41.1 41.0 41.0 40.9 40.8 40.7 40.6 40.5 40.4 40.3
94 40.3 40.2 40.1 40.0 39.9 39.8 39.8 39.7 39.6 39.5
95 39.4 39.3 39.3 39.2 39.1 39.0 38.9 38.8 38.8 38.7
96 38.6 38.5 38.4 38.4 38.3 38.2 38.1 38.0 38.0 37.9
97 37.8 37.7 37.7 37.6 37.5 37.4 37.3 37.3 37.2 37.1
98 37.0 37.0 36.9 36.8 36.7 36.7 36.6 36.5 36.4 36.4
99 36.3 36.2 36.2 36.1 36.0 35.9 35.9 35.8 35.7 35.6
100 35.6 35.5 35.4 35.4 35.3 35.2 35.2 35.1 35.0 34.9
101 34.9 34.8 34.7 34.7 34.6 34.5 34.5 34.4 34.3 34.3
102 34.2 34.1 34.1 34.0 33.9 33.9 33.8 33.7 33.7 33.6
103 33.5 33.5 33.4 33.3 33.3 33.2 33.1 33.1 33.0 33.0
6