Hardness conversion Calculator

Engineering Reference

Steel Hardness Conversion

Convert between Brinell (HB), Rockwell C (HRC), Rockwell B (HRB), and Vickers (HV) hardness scales. Values are approximate and for guidance only — each scale uses a different measurement method.

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Steel Hardness Conversion Calculator

Enter a value in any one field and click Calculate — the nearest equivalent in each scale is shown. Zero indicates out of range.

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📐 Rockwell ↔ Brinell Conversion Formulas

Formula A — Convert HRC into HB

HRC RangeBrinell HB Formula
21 – 30HB = 5.970 × HRC + 104.7
31 – 40HB = 8.570 × HRC + 27.6
41 – 50HB = 11.158 × HRC − 79.6
51 – 60HB = 17.515 × HRC − 401

Formula B — Convert HRB into HB

HRB RangeBrinell HB Formula
55 – 69HB = 1.646 × HRB + 8.7
70 – 79HB = 2.394 × HRB − 42.7
80 – 89HB = 3.297 × HRB − 114
90 – 100HB = 5.582 × HRB − 319

Source: ASTM A 370 standard. Values are approximate; no universal conversion formula exists across all scales.

📋 Table A — HRC to HB, HV & Tensile Strength (ASTM A 370)
HRC HB (Brinell 3000 kgf) HV (Vickers 30 kgf) Rm — Tensile Strength (MPa)
Diamond penetratorBrinell 3000 KgfVickers 30N/mm² MPa
20226238760
21231243770
22237248790
23243254810
24247260820
25253266850
26258272860
27264279880
28271286900
29279294930
30286302950
31294310970
323013181010
333113271030
343193361050
353273451080
363363541110
373443631140
383533721180
393623821220
403713921250
413814021300
423904121340
434004231390
444094341430
454214461480
464324581520
474424711580
484554841640
494684981700
504825131760
514965281820
525125441880
535255601950
545435772010
555605952070
565776132160
575956332240
586156532330
596346742420
60654697
61670720
62688746
63706772
64722800
65739832
66865
67900
68940
📋 Table B — HRB to HB, HV & Tensile Strength (ASTM A 370)
HRB HB (Brinell 3000 kgf) HV (Vickers 30 kgf) Rm — Tensile Strength (MPa)
Ball 1/16"Brinell 3000 KgfVickers 30N/mm² MPa
4992320
5194330
54
55100100340
56101101
57103103350
58104104
59106106360
60107107
61108108
62110110370
63112112
64114114
65116116385
66117117395
67119119400
68121121405
69123123415
70125125420
71127127425
72130130435
73132132440
74135135450
75137137455
76139139460
77141141470
78144144475
79147147485
80150150495
81153153505
82156156530
83159159550
84162162560
85165165565
86169169570
87172172580
88176176590
89180180605
90185185615
91190190620
92195195635
93200200650
94205205675
95210210690
96216216705
97222222715
98228228750
99234234785
100240240800

HRC — Diamond penetrator 120°, load 1470 N (150 kgf), duration 30 seconds.

HRB — Ball 1/16″, load 980 N (100 kgf), duration 30 seconds.

HB — Ball 10 mm, load 29,400 N (3000 kgf), duration 15 seconds.

BHN — Brinell Hardness Number — same meaning as HB.

HV — Diamond penetrator 136°, load 294 N (30 kgf), duration 15 seconds.

⬇ Download Hardness Conversion Chart

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