phase II 900-365, Instruction Manual, Page: 17 / 22

13
Approximate Hardness Conversion Numbers for Non ‐ Austenitic Steels
(Rockwell C Hardness Range) A
Brinell Hardness Number
C
Rockwell Superficial Rockwell Number
Rockwell
C
150kgf
(HRC) Vickers
(HV) 10‐mm
Standard
ball
3000kgf
(HBS)
10‐mm
Carbide
ball
3000kgf
(HBW)
Knoop
500‐gf
and
Over
(HK)
A
Scale
60 kgf
(HRA) D Scale
100kgf
(HRD) 15‐N
Scale
15‐kgf
(HR15N) 30‐N
Scale
30‐kgf
(HR30N) 45‐N
Scale
45‐kgf
(HR45N) Scleroscope
Hardness
D
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
940
900
865
832
800
772
746
720
697
674
653
633
613
595
577
560
544
528
513
498
484
471
458
446
434
423
412
402
392
382
372
363
354
345
336
327
318
310
302
294
286
279
272
266
…
…
…
…
…
…
…
…
…
…
…
…
…
…
…
…
(500)
(487)
(475)
(464)
451
442
432
421
409
400
390
381
371
362
353
344
336
327
319
311
301
294
286
279
271
264
258
253
…
…
…
(739)
(722)
(705)
(688)
(670)
(654)
634
615
595
577
560
543
525
512
496
481
469
455
443
432
421
409
400
390
381
371
362
353
344
336
327
319
311
301
294
286
279
271
264
258
253
920
895
870
846
822
799
776
754
732
710
690
670
650
630
612
594
576
558
542
526
510
495
480
466
452
438
426
414
402
391
380
370
360
351
342
334
326
318
311
304
297
290
284
278
85.6
85.0
84.5
83.9
83.4
82.8
82.3
81.8
81.2
80.7
80.1
79.6
79.0
78.5
78.0
77.4
76.8
76.3
75.9
75.2
74.7
74.1
73.6
73.1
72.5
72.0
71.5
70.9
70.4
69.9
69.4
68.9
68.4
67.9
67.4
66.8
66.3
65.8
65.3
64.8
64.3
63.8
63.3
62.8
76.9
76.1
75.4
74.5
73.8
73.0
72.2
71.5
70.7
69.9
69.2
68.5
67.7
66.9
66.1
65.4
64.6
63.8
63.1
62.1
61.4
60.8
60.0
59.2
58.5
57.7
56.9
56.2
55.4
54.6
53.8
53.1
52.3
51.5
50.8
50.0
49.2
48.4
47.7
47.0
46.1
45.2
44.6
43.8
93.2
92.9
92.5
92.2
91.8
91.4
91.1
90.7
90.2
89.8
89.3
88.9
88.3
87.9
87.4
86.9
86.4
85.9
85.5
85.0
84.5
83.9
83.5
83.0
82.5
82.0
81.5
80.9
80.4
79.9
79.4
78.8
78.3
77.7
77.2
76.6
76.1
75.6
75.0
74.5
73.9
73.3
72.8
72.2
84.4
83.6
82.8
81.9
81.1
80.1
79.3
78.4
77.5
76.6
75.7
74.8
73.9
73.0
72.0
71.2
70.2
69.4
68.5
67.6
66.7
65.8
64.8
64.0
63.1
62.2
61.3
60.4
59.5
58.6
57.7
56.8
55.9
55.0
54.2
53.3
52.1
51.3
50.4
49.5
48.6
47.7
46.8
45.9
75.4
74.2
73.3
72.0
71.0
69.9
68.8
67.7
66.6
65.5
64.3
63.2
62.0
60.9
59.8
58.6
57.4
56.1
55.0
53.8
52.5
51.4
50.3
49.0
47.8
46.7
45.5
44.3
43.1
41.9
40.8
39.6
38.4
37.2
36.1
34.9
33.7
32.5
31.3
30.1
28.9
27.8
26.7
25.5
97.3
95.0
92.7
90.6
88.5
86.5
84.5
82.6
80.8
79.0
77.3
75.6
74.0
72.4
70.9
69.4
67.9
66.5
65.1
63.7
62.4
61.1
59.8
58.5
57.3
56.1
54.9
53.7
52.6
51.5
50.4
49.3
48.2
47.1
46.1
45.1
44.1
43.1
42.2
41.3
40.4
39.5
38.7
37.8