126 DEPARTMENT BULLETIN 1216, U. S. DEPT. OF AGRICULTURE 
Table 12. — Brinell hardness numbers — Continued 
Brinell 
Brinell 
Brinell 
Brinell 
Brinell 
Di- ! hardness 
Di- 
hardness 
Di- 
hardness 
Di- 
hardness 
Di- 
hardness 
am- 
0. 
am- 
No. 
am- 
No. 
am- 
No. 
am- 
No. 
eter of 
inden- 
eter of 
inden- 
eter of 
inden- 
eter of 
inden- 
eter of 
inden- 
tation 
500- 
3,000- 
tation 
500- 
3,000- 
tation 
500- 
3,000- 
: tation 
500- 
3,000- 
tation 
500- 
3,000- 
load 
load 
load 
load 
load 
load 
load 
load 
load 
load 
Mm. 
Kg. 
Kg. 
Mm. 
Kg. 
*,. 
Mm. 
Kg. 
Kg. 
Mm. 
Kg. 
Kg. 
Mm. 
Kg. 
Kg. 
5.50 
19.3 
116 
5. >v0 
17.2 
103 
6.10 
15.3 
92.0 
6.40 
13.7 
82.5 
6.70 
12.4 
74. 1 
5.51 
19.2 
115 
5.81 
17.1 
103 
6.11 
15.3 
91.7 
6.41 
13.7 
82.2 
6.71 
12.3 
73.9 
5.52 
19.2 
115 
5.82 
17.0 
102 
6.12 
15.2 
91.3 
6.42 
13.6 
81.9 
6.72 
12.3 
73.6 
5.53 
19.1 
114 
5.83 
17.0 
102 
6.13 
15.2 
91.0 
I 6.43 
13.6 
81.6 
6.73 
12.2 
73.4 
5.54 
19.0 
114 
5.84 
16.9 
101 
6.14 
15.1 
90.6 
| 6.44 
13.5 
81.3 
6.74 
12.2 
73.1 
5.55 
1\ ' 
114 
5.85 
16.8 
101 
6.15 
15.1 
90.3 
6.45 
13.5 
81.0 
6.75 
12.1 
72.8 
5.56 
18.9 
113 
5.86 
16.8 
101 
6.16 
15.0 
90.0 
: 6.46 
13.4 
80.7 
6.76 
12.1 
72.6 
5.57 
18.8 
113 
5.87 
16.7 
100 
6.17 
14.9 
89.6 
6.47 
13.4 
80.4 
6.77 
12.1 
72.3 
5.58 
18.7 
112 
5.88 
16.7 
99.9 
6.18 
14.9 
89.3 
j 6.48 
13.4 
80.1 
6.78 
12.0 
72.1 
5.59 
112 
5.89 
16.6 
99.5 
6.19 
14.8 
89.0 
! 6.49 
13.3 
79.8 
6.79 
12.0 
71.8 
5.60 
18.6 
111 
5.90 
16.5 
99.2 
6.20 
14.8 
88.7 
: 6.50 
13.3 
79.6 
6.80 
11.9 
71.6 
5.61 
18.5 
111 
5.91 
16.5 
98.8 
6.21 
14.7 
88.3 
6.51 
13.2 
79.3 
6.81 
11.9 
71.3 
5.62 
18.4 
110 
5.92 
16.4 
98.4 
6.22 
14.7 
88.0 
1 6.52 
13.2 
79.0 
6.82 
11.8 
71.1 
5.63 
18.3 
110 
5.93 
16.3 
98.0 
6.23 
14.6 
87.7 
! 6.53 
13.1 
78.7 
6.83 
11.8 
70.8 
5.64 
18.3 
110 
5.94 
16.3 
97.7 
6.24 
14.6 
87.4 
6.54 
13.1 
78.4 
6.84 
11.8 
70.6 
5.65 
18.2 
109 
5.95 
16.2 
97.3 
6.25 
14.5 
87.1 
6.55 
13.0 
78.2 
6.85 
11.7 
70.4 
5. 66 
18.1 
109 
5.96 
16.2 
96.9 
6.26 
14.5 
86.7 
6.56 
13.0 
77.9 
6.86 
11.7 
70.1 
5.67 
18.1 
108 
5.97 
16.1 
96.6 
6.27 
14.4 
86.4 
6.57 
12.9 
77.6 
6.87 
11.6 
69.9 
5.68 
18.0 
108 
5.98 
16.0 
96.2 
6.28 
14.4 
86.1 
6.58 
12.9 
77.3 
6.88 
11.6 
69. 6 
5.69 
17.9 
107 
5.99 
16.0 
95.9 
6.29 
14.3 
85.8 
6.59 
12.8 
77.1 
6.89 
11.6 
69^4 
5.70 
17.8 
107 
6.00 
15.9 
95.5 
6.30 
14.2 
85.5 
6.60 
12.8 
76.8 
6.90 
11.5 
69. 2 
5.71 
17.8 
107 
6.01 
15.9 
95.1 
6.31 
14.2 
85.2 
6.61 
12.8 
76.5 
6.91 
11.5 
6&9 
5.72 
17.7 
106 
6.02 
15.8 
94.8 
6.32 
14.1 
84.9 
6.62 
12.7 
76.2 
6.92 
11.4 
68.7 
5.73 
17. 6 
106 
6.03 
15.7 
94.4 
6.33 
14. 1 
84.6 
6.63 
12.7 
76.0 
6.93 
11.4 
68.4 
5.74 
17. 6 
105 
6.04 
15. 7 
94.1 
6.34 
14.0 
84.3 
6.64 
12.6 
75.7 
6.94 
11.4 
68.2 
5. 75 
17.5 
105 
6.05 
15.6 
93.7 
6.35 
14.0 
84.0 
6.65 
12.6 
75.4 
6.95 
11.3 
68.0 
5.76 
17.4 
105 
6.06 
15.6 
93.4 
6.36 
13.9 
83.7 
6.66 
12.5 
75.2 
6.96 
11.3 
67.7 
5. 77 
17.4 
104 
6.07 
15.5 
93.0 
6.37 
13.9 
83.4 
6.67 
12.5 
74.9 
6.97 
11.3 
67.5 
5.78 
17.3 
104 
6.08 
15.4 
92.7 
6.38 
13.8 
83.1 
6.68 
12.4 
74.7 
6.98 
11.2 
67.3 
5.79 
17.2 
103 
6.09 
15.4 
92.3 
6.39 
13.8 
82.8 
6.69 
12.4 
74.4 
6.99 
11.2 
67.0 
APPARATUS 
1. The divisions on the micrometer scale of the microscope or other measur- 
ing device used for the measurement of the diameter of impression shall be 
such as to permit the direct measuring of the diameter to 0.1 millimeter and 
the estimation of the diameter to 0.01 millimeter. 
2. (a) The balls used in Brinell hardness testing shall 
steel or other equally hard material. 
(6) A ball to be suitable for use shall not show a permanent change in 
diameter greater than <».0025 millimeter (0.0001 inch) when pressed with a 
force of 3,000 kilograms against a piece of steel having a Brinell hardness 
number of 500 or greater. 65 
(c) If a ball is used in a test of a specimen which shows a Brinell hardness 
number greater than 500, the ball shall be remeasured after the test. Should 
the ball show a permanent change in diameter greater than that permitted in 
paragraph ( b ) , the ball shall be unsuitable for further use in a standard test. 
3. The standard ball for Brinell hardness testing shall be 10 millimeters 
(0.3937 inch) in diameter with a deviation from this value of not more than 
0.01 millimeter (0.0004 inch) in any diameter, but the diameter of any ball 
measured at various points shall be constant within a tolerance of ±0.0025 
millimeter (0.0001 inch). 
For testing very small specimens or very thin specimens it is sometimes 
necessary to make Brinell hardness tests with a ball less than 10 millimeters in 
diameter. For such tests (which are not to be regarded as standard Brinell 
85 In testing softer metals, it is not, of course, necessary to have balls of this extreme 
hardness. However, a ball to be suitable for use should withstand pressure against the 
hardest material to be tested without showing a permanent change in diameter greater 
than 0.0025 millimeters. 
66 See footnote 64. 
