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# Hardness Conversion Calculator

Different hardness scalesSteel hardness conversion chartCalculating hardness conversion with this calculatorFAQs

Our hardness conversion calculator enables you to convert steel hardness from one scale to another. You're not the first to wish for an accurate conversion from Brinell hardness number to Rockwell or Vickers scale and vice versa. But for the reasons we'll get to in the following article, this conversion is only approximate!

Below, we shall briefly look at the three different hardness scales before learning how to convert HB to HRC or calculate HV to HRB with the help of a hardness conversion chart.

## Different hardness scales

The hardness number of a material indicates its resistance to plastic deformation. The higher the hardness number, the higher the hardness of the material. We get these numbers by performing indentation tests on the material. The three standard hardness scales in use are:

1. Brinell hardness number (HB, HBW, or BHN), which depends on the diameter of the spherical indentor and the indentation. You can learn more about this with our Brinell hardness number calculator.

2. Rockwell hardness number, calculated from the indentation depth. Different scales under the Rockwell scale are labeled HRA, HRB, HRC, etc. For more on the Rockwell hardness, visit our Rockwell hardness conversion calculator.

3. Vickers hardness number (HV), independent of the indentor size, is one of the broadest hardness scales used. Our Vickers hardness number calculator will help you calculate the HV of any material.

## Steel hardness conversion chart

The hardness of steel depends on several factors, such as its composition, manufacturing, and heat-treating processes. The different hardness scales use different loads, different indentor shapes, and different measurements to obtain the hardness number. There are no straightforward formulae to establish relationships between the different scales, making accurate conversion impossible in most cases.

However, the following steel hardness conversion table was tabulated through extensive data, allowing for approximate conversions.

Hardness conversion table for steel acquired through many experiments and computer plots. Values are approximate.

Brinell HB

Rockwell C HRC

Rockwell B HRB

Vickers HV

800

72

--

--

780

71

--

--

760

70

--

--

752

69

--

--

746

67

--

--

745

68

--

--

735

66

--

--

711

65

--

--

695

64

--

--

681

63

--

--

658

62

--

--

642

61

--

--

627

60

--

--

613

59

--

--

601

58

--

746

592

57

--

727

572

56

--

694

552

55

--

649

534

54

120

589

513

53

119

567

504

52

118

549

486

51

118

531

469

50

117

505

468

49

117

497

456

48

116

490

445

47

115

474

430

46

115

458

419

45

114

448

415

44

114

438

402

43

114

424

388

42

113

406

375

41

112

393

373

40

111

388

360

39

111

376

348

38

110

361

341

37

109

351

331

36

109

342

322

35

108

332

314

34

108

320

308

33

107

311

300

32

107

303

290

31

106

292

277

30

105

285

271

29

104

277

264

28

103

271

262

27

103

262

255

26

102

258

250

25

101

255

245

24

100

252

240

23

100

247

233

22

99

241

229

21

98

235

223

20

97

227

216

19

96

222

212

18

95

218

208

17

95

210

203

16

94

201

199

15

93

199

191

14

92

197

190

13

92

186

186

12

91

184

183

11

90

183

180

10

89

180

175

9

88

178

170

7

87

175

167

6

86

172

166

5

86

168

163

4

85

162

160

3

84

160

156

2

83

158

154

1

82

152

149

--

81

149

147

--

80

147

143

--

79

146

141

--

78

144

139

--

77

142

137

--

76

140

135

--

75

137

131

--

74

134

127

--

72

129

121

--

70

127

116

--

68

124

114

--

67

121

111

--

66

118

107

--

64

115

105

--

62

112

103

--

61

108

95

--

56

104

90

--

52

95

81

--

41

85

76

--

37

80

For example, let's consider a conversion from HV to HRC. Say the steel sample's hardness is 262 HV. By looking up 262 HV on this table, you can see its Rockwell C equivalent is 27 HRC.

You can skip such manual steps by instead asking our calculator to convert HV to HRC. The following section teaches you how best to use this calculator.

🔎 What if, instead of 262 HV, you need to convert 269 HV to HRC?

Generally, when the hardness number you need to convert falls between two values in the table, we reach for the lower value instead of the upper one. Since 269 HV falls between 262 HV and 271 HV on the table, we go for 262 HV and use that to convert to other scales.

## Calculating hardness conversion with this calculator

Our calculator can convert steel hardness between different scales in two steps:

1. Select which hardness number you want to convert from. You can choose from the following:

• Brinell hardness number;

• Rockwell C scale;

• Rockwell B scale; and

• Vickers hardness number.

2. Enter the hardness number. The calculator will convert it to all the other remaining hardness scales!

FAQs

### What is the Vickers hardness number of steel with 300 BHN?

The equivalent hardness of a steel sample of 300 BHN in the Vickers scale is 303 HV. To perform this conversion, refer to a steel harness conversion chart and follow these steps:

1. Look up the Brinell hardness, 300 BHN.

2. Find the equivalent Vickers hardness in the same row, 303 HV.

3. Verify your result with our hardness conversion calculator.

### What is the hardness of mild steel?

Mild steel has an approximate Rockwell hardness number of 70 HRB, equivalent to 121 BHN (Brinell hardness number) and 127 HV (Vickers).

### What is the relationship between hardness and tensile strength of steel?

In steel, indentation hardness varies linearly with its tensile strength. However, this relationship is "imperfect" – limited to small ranges of hardness and tensile strength.

### What are the units of Brinell, Rockwell, and Vickers hardness numbers?

Brinell and Vickers hardness numbers use the unit kgf/mm2, similar to pressure. On the other hand, Rockwell hardness (scales B and C) are dimensionless quantities.