Rockwell hardness

HB

HV

HRA

HRB

HRC

HRD

HR15N

HR30N

HR45N

HS

2.50

601³⁾

640

79.8

-

57.3

68.7

89.0

75.1

63.5

77

2055

2.55

578³⁾

615

79.1

-

56.0

67.7

88.4

73.9

62.1

75

1979

2.60

555³⁾

591

78.4

-

54.7

66.7

87.8

72.7

60.6

73

1903

2.65

534³⁾

569

77.8

-

53.5

65.8

87.2

71.6

59.2

71

1834

514²⁾

553

77.1

-

52.5

65.0

86.7

70.7

58.0

-

1765

514³⁾

547

76.9

-

52.1

64.7

86.5

70.3

57.6

70

1765

495¹⁾

539

76.7

-

51.6

64.3

86.3

69.9

56.9

-

1703

495²⁾

530

76.4

-

51.1

63.9

86.0

69.5

56.2

-

1703

495³⁾

528

76.3

-

51.0

63.8

85.9

69.4

56.1

68

1703

477¹⁾

516

75.9

-

50.3

63.2

85.6

68.7

55.2

-

1641

477²⁾

508

75.6

-

49.6

62.7

85.3

68.2

54.5

-

1641

477³⁾

508

75.6

-

49.6

62.7

85.3

68.2

54.5

66

1641

461¹⁾

495

75.1

-

48.8

61.9

84.9

67.4

53.5

-

1579

461²⁾

491

74.9

-

48.5

61.7

84.7

67.2

53.2

-

1579

461³⁾

491

74.9

-

48.5

61.7

84.7

67.2

53.2

65

1579

444¹⁾

474

74.3

-

47.2

61.0

84.1

66.0

51.7

-

1517

444²⁾

472

74.2

-

47.1

60.8

84.0

65.8

51.5

-

1517

444³⁾

472

74.2

-

47.1

60.8

84.0

65.8

51.5

63

1517

2.95

429

455

73.4

-

45.7

59.7

83.4

64.6

49.9

61

1462

3.00

415

440

72.8

-

44.5

58.8

82.8

63.5

48.4

59

1407

3.05

401

425

72.0

-

43.1

57.8

82.0

62.3

46.9

58

1351

3.10

388

410

71.4

-

41.8

56.8

81.4

61.1

45.3

56

1303

3.15

375

396

70.6

-

40.4

55.7

80.6

59.9

43.6

54

1255

3.20

363

383

70.0

-

39.1

54.6

80.0

58.7

42.0

52

1213

3.25

352

372

69.3

(110.0)

37.9

53.8

79.3

57.6

40.5

51

1172

3.30

341

360

68.7

(109.0)

36.6

52.8

78.6

56.4

39.1

50

1138

3.35

331

350

68.1

(108.5)

35.5

51.9

78.0

55.4

37.8

48

1103

3.40

321

339

67.5

(108.0)

34.3

51.0

77.3

54.3

36.4

47

1069

3.45

311

328

66.9

(107.5)

33.1

50.0

76.7

53.3

34.4

46

1034

3.50

302

319

66.3

(107.0)

32.1

49.3

76.1

52.2

33.8

45

1007

3.55

293

309

65.7

(106.0)

30.9

48.3

75.5

51.2

32.4

43

979

3.60

285

301

65.3

(105.5)

29.9

47.6

75.0

50.3

31.2

-

951

3.65

277

292

64.6

(104.5)

28.8

46.7

74.4

49.3

29.9

41

924

3.70

269

284

64.1

(104.0)

27.6

45.9

73.7

48.3

28.5

40

903

3.75

262

276

63.6

(103.0)

26.6

45.0

73.1

47.3

27.3

39

883

3.80

255

269

63.0

(102.0)

25.4

44.2

72.5

46.2

26.0

38

862

3.85

248

261

62.5

(101.0)

24.2

43.2

71.7

45.1

24.5

37

841

3.90

241

253

61.8

100.0

22.8

42.0

70.9

43.9

22.8

36

820

3.95

235

247

61.4

99.0

21.7

41.4

70.3

42.9

21.5

35

800

4.00

229

241

60.8

98.2

20.5

40.5

69.7

41.9

20.1

34

779

4.05

223

234

-

97.3

(18.8)

-

-

-

-

-

758

4.10

217

228

-

96.4

(17.5)

-

-

-

-

33

738

4.15

212

222

-

95.5

(16.0)

-

-

-

-

-

717

4.20

207

218

-

94.6

(15.2)

-

-

-

-

32

696

4.25

201

212

-

93.8

(13.8)

-

-

-

-

31

683

4.30

197

207

-

92.8

(12.7)

-

-

-

-

30

669

4.35

192

202

-

91.9

(11.5)

-

-

-

-

29

655

4.40

187

196

-

90.7

(10.0)

-

-

-

-

-

641

4.45

183

192

-

90.0

(9.0)

-

-

-

-

28

627

4.50

179

188

-

89.0

(8.0)

-

-

-

-

27

614

4.55

174

182

-

87.8

(6.4)

-

-

-

-

-

600

4.60

170

178

-

86.8

(5.4)

-

-

-

-

26

586

4.65

167

175

-

86.0

(4.4)

-

-

-

-

-

572

4.70

163

171

-

85.0

(3.3)

-

-

-

-

25

565

4.80

156

163

-

82.9

(0.9)

-

-

-

-

-

538

4.90

149

156

-

80.8

-

-

-

-

-

23

517

5.00

143

150

-

78.7

-

-

-

-

-

22

496

5.10

137

143

-

76.4

-

-

-

-

-

21

483

5.20

131

137

-

74.0

-

-

-

-

-

-

455

5.30

126

132

-

72.0

-

-

-

-

-

20

441

5.40

121

127

-

69.8

-

-

-

-

-

19

427

5.50

116

122

-

67.6

-

-

-

-

-

18

414

5.60

111

117

-

65.7

-

-

-

-

-

15

400

5.70

107¹⁾

113

-

64

-

-

-

-

-

-

379

5.80

103¹⁾

108

-

61

-

-

-

-

-

-

365