Approximate Equivalent Hardness Numbers for Cartridge Brass (70% Cu, 30% Zn)

Rockwell Hardness Number		Brinell Hardness Number
B scale, 100 kgf 1/16 in. (1.588 mm) ball HRB	F scale, 60 kgf 1/16 in. (1.588 mm) ball HRF	500 kgf, 10 mm ball HBS
93.5	110.0	169
--	109.5	167
93.0	--	166
92.5	109.0	164
92.0	--	162
91.5	108.5	161
91.0	--	159
90.5	108.0	157
90.0	107.5	156
89.0	--	154
88.5	107.0	152
88.0	--	150
87.5	106.5	149
87.0	--	147
86.0	106.0	146
85.5	--	144
85.0	105.5	142
84.0	105.0	141
83.5	--	139
83.0	104.5	138
82.0	104.0	136
81.5	103.5	135
80.5	103.0	133
80.0	--	131
79.0	102.5	129
78.0	102.0	128
77.5	101.5	126
77.0	101.0	124
76.0	100.5	122
75.0	100.0	121
74.5	99.5	120
73.5	99.0	118
73.0	98.5	116
72.0	98.0	114
71.0	97.5	113
70.0	97.0	112
69.0	96.5	110
68.0	96.0	108
67.0	95.5	106
66.0	95.0	105
65.0	94.5	103
64.0	94.0	101
63.0	93.0	99
62.0	92.6	97
61.0	92.0	95
59.5	91.2	94
58.0	90.5	92
57.0	89.8	90
56.0	89.0	88
54.0	88.0	86
53.0	87.2	85
51.0	86.3	83
49.5	85.4	82
47.5	84.4	80
46.0	83.5	79
44.0	82.3	77
42.0	81.2	76
40.0	80.0	74
37.5	78.6	72
35.0	77.4	70
32.0	76.0	68
30.0	74.8	66
27.5	73.2	64
24.5	71.8	63
21.5	70.0	62
18.5	68.5	61
15.5	66.8	59
12.5	65.0	57
10.0	62.5	55
--	61.0	53
--	58.8	52
--	56.5	50
--	53.5	48
--	50.5	47
--	49.0	46
--	47.0	45
--	45.0	44
--	43.0	43
--	40.0	42

Source: ASTM E140