HARDNESS CONVERSION TABLE (Approximate Value) |
Brinell |
Rockwell |
Tensile Strength |
Diameter 3000 Kg. Load 10 mm. Ball |
Hardness No. |
C |
B |
A |
15-N |
Shore |
Tensile Strength 1000 Lb./Sq. In. |
2.25 |
745 |
65.3 |
— |
84.1 |
92.3 |
91 |
— |
2.30 |
712 |
— |
— |
— |
— |
— |
— |
2.35 |
682 |
61.7 |
— |
82.2 |
91.0 |
84 |
— |
2.40 |
653 |
60.0 |
— |
81.2 |
90.2 |
81 |
— |
2.45 |
627 |
58.7 |
— |
80.5 |
89.6 |
79 |
— |
2.50 |
601 |
57.3 |
— |
79.8 |
89.0 |
77 |
— |
2.55 |
578 |
56.0 |
— |
79.1 |
88.4 |
75 |
— |
2.60 |
555 |
54.7 |
— |
78.4 |
87.8 |
73 |
298 |
2.65 |
534 |
53.5 |
— |
77.8 |
87.2 |
71 |
288 |
2.70 |
514 |
52.1 |
— |
76.9 |
86.5 |
70 |
274 |
2.75 |
495 |
51.0 |
— |
76.3 |
85.9 |
68 |
264 |
2.80 |
477 |
49.6 |
— |
75.6 |
85.3 |
66 |
252 |
2.85 |
461 |
48.5 |
— |
74.9 |
84.7 |
65 |
242 |
2.90 |
444 |
47.1 |
— |
74.2 |
84.0 |
63 |
230 |
2.95 |
429 |
45.7 |
— |
73.4 |
83.4 |
61 |
219 |
3.00 |
415 |
44.5 |
— |
72.8 |
82.8 |
59 |
212 |
3.05 |
401 |
43.1 |
— |
72.0 |
82.0 |
58 |
202 |
3.10 |
388 |
41.8 |
— |
71.4 |
81.4 |
56 |
193 |
3.15 |
375 |
40.4 |
— |
70.6 |
80.6 |
54 |
184 |
3.20 |
363 |
39.1 |
— |
70.0 |
80.0 |
52 |
177 |
3.25 |
352 |
37.9 |
(110.0) |
69.3 |
79.3 |
51 |
170 |
3.30 |
341 |
36.6 |
(109.0) |
68.7 |
78.6 |
50 |
163 |
3.35 |
331 |
35.5 |
(108.5) |
68.1 |
78.0 |
48 |
158 |
3.40 |
321 |
34.3 |
(108.0) |
67.5 |
77.3 |
47 |
152 |
3.45 |
311 |
33.1 |
(107.5) |
66.9 |
76.7 |
46 |
147 |
3.50 |
302 |
32.1 |
(107.0) |
66.3 |
76.1 |
45 |
143 |
3.55 |
293 |
30.9 |
(106.0) |
65.7 |
75.5 |
43 |
139 |
3.60 |
285 |
29.9 |
(105.5) |
65.3 |
75.0 |
— |
135 |
3.65 |
277 |
28.8 |
(104.5) |
64.6 |
74.4 |
41 |
131 |
3.70 |
269 |
27.6 |
(104.0) |
64.1 |
73.7 |
40 |
128 |
3.75 |
262 |
26.6 |
(103.0) |
63.6 |
73.1 |
39 |
125 |
3.80 |
255 |
25.4 |
(102.0) |
63.0 |
72.5 |
38 |
121 |
3.85 |
248 |
24.2 |
(101.0) |
62.5 |
71.7 |
37 |
118 |
3.90 |
241 |
22.8 |
100.0 |
61.8 |
70.9 |
36 |
114 |
3.95 |
235 |
21.7 |
99.0 |
61.4 |
70.3 |
35 |
111 |
4.00 |
229 |
20.5 |
98.2 |
60.8 |
69.7 |
34 |
109 |
4.05 |
223 |
(18.8) |
97.3 |
— |
— |
— |
104 |
4.10 |
217 |
(17.5) |
96.4 |
— |
— |
33 |
103 |
4.15 |
212 |
(16.0) |
95.5 |
— |
— |
— |
100 |
4.20 |
207 |
(15.2) |
94.6 |
— |
— |
32 |
99 |
4.25 |
201 |
(13.8) |
93.8 |
— |
— |
31 |
97 |
4.30 |
197 |
(12.7) |
92.8 |
— |
— |
30 |
94 |
4.35 |
192 |
(11.5) |
91.9 |
— |
— |
29 |
92 |
4.40 |
187 |
(10.0) |
90.7 |
— |
— |
— |
90 |
4.45 |
183 |
(9.0) |
90.0 |
— |
— |
28 |
89 |
4.50 |
179 |
(8.0) |
89.0 |
— |
— |
27 |
88 |
4.55 |
174 |
(6.4) |
87.8 |
— |
— |
— |
86 |
4.60 |
170 |
(5.4) |
86.8 |
— |
— |
26 |
84 |
4.65 |
167 |
(4.4) |
86.0 |
— |
— |
— |
83 |
4.70 |
163 |
(3.3) |
85.0 |
— |
— |
25 |
82 |
4.80 |
156 |
(0.9) |
82.9 |
— |
— |
— |
80 |
4.90 |
149 |
— |
80.8 |
— |
— |
23 |
— |
5.00 |
143 |
— |
78.7 |
— |
— |
22 |
— |
5.10 |
137 |
— |
76.4 |
— |
— |
21 |
— |
5.20 |
131 |
— |
74.0 |
— |
— |
— |
— |
5.30 |
126 |
— |
72.0 |
— |
— |
20 |
— |
5.40 |
121 |
— |
69.8 |
— |
— |
19 |
— |
5.50 |
116 |
— |
67.6 |
— |
— |
18 |
— |
5.60 |
111 |
— |
65.7 |
— |
— |
15 |
— |
Hardness values are from SAE-ASM-ASTM Committees on Hardness Conversions as printed in ASTME 140, Table 3. Tensile Strength values are from Federal Test Methods Standard No. 151A-method 241.2 dated Jan. 10 1961. |