|

Hardness Conversion Chart
Approximate equivalent hardness numbers for carbon and alloy steels
Rockwell
|
Rockwell Superficial
|
Brinell
|
Vickers
|
Knoop
|
Scleroscope
|
Approx. Tensile Strength of Steel (PSI)
|
A Scale
|
B Scale
|
C Scale
|
D Scale
|
15N Scale
|
30N Scale
|
45N Scale
|
3000 kg 10 mm Ball
|
|
500 g or greater Load
|
|
60 kg Diam. Brale |
100 kg 1/16" Ball
|
150 kg Diam. Brale
|
100 kg Diam. Brale |
15 kg Diam. Brale
|
30 kg Diam. Brale
|
45 kg Diam. Brale
|
92 |
- |
80.0 |
87 |
97 |
92 |
87 |
- |
1865 |
- |
- |
- |
92 |
- |
79.0 |
86 |
- |
92 |
87 |
- |
1787 |
- |
- |
- |
91 |
- |
78.0 |
85 |
96 |
91 |
86 |
- |
1710 |
- |
- |
- |
91 |
- |
77.0 |
84 |
- |
91 |
85 |
- |
1633 |
- |
- |
- |
90 |
- |
76.0 |
83 |
96 |
90 |
84 |
- |
1556 |
- |
- |
- |
90 |
- |
75.0 |
83 |
- |
89 |
83 |
- |
1478 |
- |
- |
- |
89 |
- |
74.0 |
82 |
95 |
89 |
82 |
- |
1400 |
- |
- |
- |
89 |
- |
73.0 |
81 |
- |
88 |
81 |
- |
1323 |
- |
- |
- |
88 |
- |
72.0 |
80 |
95 |
87 |
80 |
- |
1245 |
- |
- |
- |
87 |
- |
71.0 |
80 |
- |
87 |
79 |
- |
1160 |
- |
- |
- |
87 |
- |
70.0 |
79 |
94 |
86 |
78 |
- |
1076 |
- |
99 |
- |
86 |
- |
69.0 |
78 |
- |
85 |
77 |
- |
1004 |
- |
98 |
- |
85.6 |
- |
68.0 |
76.9 |
93.2 |
84.4 |
75.4 |
- |
940 |
920 |
97 |
- |
85.3 |
- |
67.5 |
76.5 |
93.0 |
84.0 |
74.8 |
- |
920 |
908 |
96 |
- |
85.0 |
- |
67.0 |
76.1 |
92.9 |
83.6 |
74.2 |
- |
900 |
895 |
95 |
- |
84.7 |
- |
66.4 |
75.7 |
92.7 |
83.1 |
73.6 |
- |
880 |
882 |
93 |
- |
84.4 |
- |
65.9 |
75.3 |
92.5 |
82.7 |
73.1 |
- |
860 |
867 |
92 |
- |
84.1 |
- |
65.3 |
74.8 |
92.3 |
82.2 |
72.2 |
- |
840 |
852 |
91 |
- |
83.8 |
- |
64.7 |
74.3 |
92.1 |
81.7 |
71.8 |
745* |
820 |
837 |
90 |
- |
83.4 |
- |
64.0 |
73.8 |
91.8 |
81.1 |
71.0 |
- |
800 |
822 |
88 |
- |
83.0 |
- |
63.3 |
73.3 |
91.5 |
80.4 |
70.2 |
- |
780 |
806 |
87 |
- |
82.6 |
- |
62.5 |
72.6 |
91.2 |
79.7 |
69.4 |
710* |
760 |
788 |
86 |
- |
82.2 |
- |
61.8 |
72.1 |
91.0 |
79.1 |
68.6 |
- |
740 |
772 |
84 |
- |
81.8 |
- |
61.0 |
71.5 |
90.7 |
78.4 |
67.7 |
- |
720 |
754 |
83 |
- |
81.3 |
- |
60.1 |
70.8 |
90.3 |
77.6 |
66.7 |
653* |
700 |
735 |
81 |
- |
81.1 |
- |
59.7 |
70.5 |
90.1 |
77.2 |
66.2 |
- |
690 |
725 |
- |
- |
80.8 |
- |
59.2 |
70.1 |
89.8 |
76.8 |
65.7 |
- |
680 |
716 |
80 |
329,000 |
80.6 |
- |
58.8 |
69.8 |
89.7 |
76.4 |
65.3 |
- |
670 |
706 |
- |
324,000 |
80.3 |
- |
58.3 |
69.4 |
89.5 |
75.9 |
64.7 |
620* |
660 |
697 |
79 |
- |
80.0 |
- |
57.8 |
69.0 |
89.2 |
75.5 |
64.1 |
611* |
650 |
687 |
78 |
- |
79.8 |
- |
57.3 |
68.7 |
89.0 |
75.1 |
63.5 |
601* |
640 |
677 |
77 |
309,000 |
79.5 |
- |
56.8 |
68.3 |
88.8 |
74.6 |
63.0 |
591* |
630 |
667 |
76 |
- |
79.2 |
- |
56.3 |
67.9 |
88.5 |
74.2 |
62.4 |
582* |
620 |
657 |
75 |
297,000 |
78.9 |
- |
55.7 |
67.5 |
88.2 |
73.6 |
61.7 |
573* |
610 |
646 |
- |
- |
78.6 |
- |
55.2 |
67.0 |
88.0 |
73.2 |
61.2 |
564* |
600 |
636 |
74 |
- |
78.4 |
- |
54.7 |
66.7 |
87.8 |
72.7 |
60.5 |
554* |
590 |
625 |
73 |
285,000 |
78.0 |
- |
54.1 |
66.2 |
87.5 |
72.1 |
59.9 |
545* |
580 |
615 |
72 |
- |
77.8 |
- |
53.6 |
65.8 |
87.2 |
71.7 |
59.3 |
535* |
570 |
604 |
- |
274,000 |
77.4 |
- |
53.0 |
65.4 |
86.9 |
71.2 |
58.6 |
525* |
560 |
594 |
71 |
- |
77.0 |
- |
52.3 |
64.8 |
86.6 |
70.5 |
57.8 |
517* |
550 |
583 |
70 |
263,000 |
76.7 |
- |
51.7 |
64.4 |
86.3 |
70.0 |
57.0 |
507* |
540 |
572 |
69 |
- |
76.4 |
- |
51.1 |
63.9 |
86.0 |
69.5 |
56.2 |
497* |
530 |
561 |
68 |
253,000 |
76.1 |
- |
50.5 |
63.5 |
85.7 |
69.0 |
55.6 |
488* |
520 |
550 |
67 |
- |
75.7 |
- |
49.8 |
62.9 |
85.4 |
68.3 |
54.7 |
479* |
510 |
539 |
- |
243,000 |
75.3 |
- |
49.1 |
62.2 |
85.0 |
67.7 |
53.9 |
471* |
500 |
528 |
66 |
- |
74.9 |
- |
48.4 |
61.6 |
84.7 |
67.1 |
53.1 |
460* |
490 |
517 |
65 |
235,000 |
74.5 |
- |
47.7 |
61.3 |
84.3 |
66.4 |
52.2 |
452* |
480 |
505 |
64 |
- |
74.1 |
- |
46.9 |
60.7 |
83.9 |
65.7 |
51.3 |
441 |
470 |
494 |
- |
225,000 |
73.6 |
- |
46.1 |
60.1 |
83.6 |
64.9 |
50.4 |
433 |
460 |
482 |
62 |
- |
73.3 |
- |
45.3 |
59.4 |
83.2 |
64.3 |
49.4 |
425 |
450 |
471 |
- |
- |
72.8 |
- |
44.5 |
58.8 |
82.8 |
63.5 |
48.4 |
415 |
440 |
459 |
59 |
210,000 |
72.3 |
- |
43.6 |
58.2 |
82.3 |
62.7 |
47.4 |
405 |
430 |
447 |
58 |
- |
71.8 |
- |
42.7 |
57.5 |
81.8 |
61.9 |
46.4 |
397 |
420 |
435 |
57 |
- |
71.4 |
- |
41.8 |
56.8 |
81.4 |
61.1 |
45.3 |
388 |
410 |
423 |
56 |
195,000 |
70.8 |
- |
40.8 |
56.0 |
80.8 |
60.2 |
44.1 |
379 |
400 |
412 |
55 |
- |
70.3 |
- |
39.8 |
55.2 |
80.3 |
59.3 |
42.9 |
369 |
390 |
400 |
- |
- |
69.8 |
- |
38.8 |
54.4 |
79.8 |
58.4 |
41.7 |
360 |
380 |
389 |
52 |
- |
69.2 |
- |
37.7 |
53.6 |
79.2 |
57.4 |
40.4 |
350 |
370 |
378 |
51 |
176,000 |
68.7 |
- |
36.6 |
52.8 |
78.6 |
56.4 |
39.1 |
341 |
360 |
367 |
50 |
- |
68.1 |
- |
35.5 |
51.9 |
78.0 |
55.4 |
37.8 |
331 |
350 |
356 |
48 |
166,000 |
67.6 |
- |
34.4 |
51.1 |
77.4 |
54.4 |
36.5 |
322 |
340 |
346 |
47 |
- |
67.0 |
- |
33.3 |
50.2 |
76.8 |
53.6 |
35.2 |
313 |
330 |
337 |
46 |
- |
66.4 |
- |
32.2 |
49.4 |
76.2 |
52.3 |
33.9 |
303 |
320 |
328 |
45 |
150,000 |
65.8 |
- |
31.0 |
48.4 |
75.6 |
51.3 |
32.5 |
294 |
310 |
318 |
- |
- |
65.2 |
- |
29.8 |
47.5 |
74.9 |
50.2 |
31.1 |
284 |
300 |
309 |
42 |
141,000 |
64.8 |
- |
29.2 |
47.1 |
74.6 |
49.7 |
30.4 |
280 |
295 |
305 |
- |
- |
64.5 |
- |
28.5 |
46.5 |
74.2 |
49.0 |
29.5 |
275 |
290 |
300 |
41 |
- |
64.2 |
- |
27.8 |
46.0 |
73.8 |
48.4 |
28.7 |
270 |
285 |
296 |
- |
133,000 |
63.8 |
- |
27.1 |
45.3 |
73.4 |
47.8 |
27.9 |
265 |
280 |
291 |
40 |
- |
63.5 |
- |
26.4 |
44.9 |
73.0 |
47.2 |
27.1 |
261 |
275 |
286 |
39 |
129,000 |
63.1 |
- |
25.6 |
44.3 |
72.6 |
46.4 |
26.2 |
256 |
270 |
282 |
38 |
- |
62.7 |
- |
24.8 |
43.7 |
72.1 |
45.7 |
25.2 |
252 |
265 |
277 |
- |
- |
62.4 |
- |
24.0 |
43.1 |
71.6 |
45.0 |
24.3 |
247 |
260 |
272 |
37 |
122,000 |
62.0 |
- |
23.1 |
42.2 |
71.1 |
44.2 |
23.2 |
243 |
255 |
267 |
- |
- |
61.6 |
99.5 |
22.2 |
41.7 |
70.6 |
43.4 |
22.2 |
238 |
250 |
262 |
36 |
- |
61.2 |
- |
21.3 |
41.1 |
70.1 |
42.5 |
21.1 |
233 |
245 |
258 |
35 |
115,000 |
60.7 |
98.1 |
20.3 |
40.3 |
69.6 |
41.7 |
19.9 |
228 |
240 |
253 |
34 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
235 |
- |
- |
- |
- |
96.7 |
- |
- |
- |
- |
- |
219 |
230 |
243 |
33 |
105,000 |
- |
- |
- |
- |
- |
- |
- |
- |
225 |
- |
- |
- |
- |
95.0 |
- |
- |
- |
- |
- |
209 |
220 |
234 |
32 |
100,000 |
- |
- |
- |
- |
- |
- |
- |
- |
215 |
- |
- |
- |
- |
93.4 |
- |
- |
- |
- |
- |
200 |
210 |
226 |
30 |
98,000 |
- |
- |
- |
- |
- |
- |
- |
- |
205 |
- |
- |
- |
- |
91.5 |
- |
- |
- |
- |
- |
190 |
200 |
216 |
29 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
195 |
- |
- |
90,000 |
- |
89.5 |
- |
- |
- |
- |
- |
181 |
190 |
206 |
28 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
185 |
- |
- |
- |
- |
87.1 |
- |
- |
- |
- |
- |
171 |
180 |
196 |
26 |
83,000 |
- |
- |
- |
- |
- |
- |
- |
- |
175 |
- |
- |
- |
- |
85.0 |
- |
- |
- |
- |
- |
162 |
170 |
185 |
25 |
79,000 |
- |
- |
- |
- |
- |
- |
- |
- |
165 |
- |
- |
- |
- |
81.7 |
- |
- |
- |
- |
- |
152 |
160 |
175 |
23 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
155 |
- |
- |
- |
- |
78.7 |
- |
- |
- |
- |
- |
143 |
150 |
164 |
22 |
71,000 |
- |
- |
- |
- |
- |
- |
- |
- |
145 |
- |
- |
- |
- |
75.0 |
- |
- |
- |
- |
- |
133 |
140 |
154 |
21 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
135 |
- |
- |
- |
- |
71.2 |
- |
- |
- |
- |
- |
124 |
130 |
143 |
20 |
63,000 |
- |
- |
- |
- |
- |
- |
- |
- |
125 |
- |
- |
- |
- |
66.7 |
- |
- |
- |
- |
- |
114 |
120 |
133 |
18 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
115 |
- |
- |
56,000 |
- |
62.3 |
- |
- |
- |
- |
- |
105 |
110 |
123 |
- |
- |
- |
- |
- |
- |
- |
- |
- |
- |
105 |
- |
- |
- |
- |
56.2 |
- |
- |
- |
- |
- |
95 |
100 |
112 |
- |
- |
- |
52.0 |
- |
- |
- |
- |
- |
90 |
95 |
107 |
- |
- |
- |
48.0 |
- |
- |
- |
- |
- |
86 |
90 |
102 |
- |
- |
- |
41.0 |
- |
- |
- |
- |
- |
81 |
85 |
97 |
- |
- |
* Values for tungsten carbide ball only
To download a printable pdf, click here.
References: Hardness Testing, ASM Internationals, Metals Park, OH, 1987 www.engineersedge.com www.corrosionsource.com  |
|