The information supplied here is intended to be an acceptable guide for normal conditions. For critical applications, further information and research will be necessary. The following basic assumptions have been made:

a. Bolts are new, standard finish, uncoated and not lubricated (other than the normal protective oil film)

b. The load will be 90% of the bolt yield strength

c. The coefficient of friction is 0.14

d. The final tightening sequence is achieved smoothly and slowly

If lubrication is to be applied to the nut/bolt, multiply the recommended torque by the appropriate factor shown in the table on intro to torque part 2. Alternatively, use the Torque/Tension Calculator which enables fastener and friction conditions to be modified with ease.

M


BOLT GRADE

mm


3.6

4.6

5.6

5.8

6.8

8.8

9.8

10.9

12.9

Torque in N·m

M 1.6

0.05

0.07

0.09

0.11

0.14

0.18

0.21

0.26

0.31

3.2

M 2

0.11

0.14

0.18

0.24

0.28

0.38

0.42

0.53

0.63

4

M 2.5

0.22

0.29

0.36

0.48

0.58

0.78

0.87

1.09

1.31

5

M 3

0.38

0.51

0.63

0.84

1.01

1.35

1.52

1.9

2.27

5.5

M 4

0.71

0.95

1.19

1.59

1.91

2.54

2.86

3.57

4.29

7

M 5

1.71

2.28

2.85

3.8

4.56

6.09

6.85

8.56

10.3

8

M 6

2.94

3.92

4.91

6.54

7.85

10.5

11.8

14.7

17.7

10

M 8

7.11

9.48

11.9

15.8

19

25.3

28.4

35.5

42.7

13

M 10

14.3

19.1

23.8

31.8

38.1

50.8

57.2

71.5

85.8

17

M 12

24.4

32.6

40.7

54.3

65.1

86.9

97.9

122

147

19

M 14

39

52

65

86.6

104

139

156

195

234

22

M 16

59.9

79.9

99.8

133

160

213

240

299

359

24

M 18

82.5

110

138

183

220

293

330

413

495

27

M 20

117

156

195

260

312

416

468

585

702

30

M 22

158

211

264

352

422

563

634

792

950

32

M 24

202

270

337

449

539

719

809

1,011

1,213

36

M 27

298

398

497

663

795

1,060

1,193

1,491

1,789

41

M 30

405

540

675

900

1,080

1,440

1,620

2,025

2,430

46

M 33

550

734

917

1,223

1,467

1,956

2,201

2,751

3,301

50

M 36

708

944

1,180

1,573

1,888

2,517

2,832

3,540

4,248

55

M 39

919

1,226

1,532

2,043

2,452

3,269

3,678

4,597

5,517

60

M 42

1,139

1,518

1,898

2,530

3,036

4,049

4,555

5,693

6,832

65

M 45

1,425

1,900

2,375

3,167

3,800

5,067

5,701

7,126

8,551

70

M 48

1,716

2,288

2,860

3,813

4,576

6,101

6,864

8,580

10,296

75

M 52

2,210

2,947

3,684

4,912

5,895

7,859

8,842

11,052

13,263

80

M 56

2,737

3,650

4,562

6,083

7,300

9,733

10,950

13,687

16,425

85

M 60

3,404

4,538

5,673

7,564

9,076

12,102

13,614

17,018

20,422

90

M 64

4,100

5,466

6,833

9,110

10,932

14,576

16,398

20,498

24,597

95

M 68

4,963

6,617

8,271

11,029

13,234

17,646

19,851

24,814

29,777

100