Unified Inch Bolt and Screw Torque Values

TS1671
TS1671-UN-01MAY03


 

SAE Grade 1

SAE Grade 21

SAE Grade 5, 5.1, or 5.2

SAE Grade 8 or 8.2

Bolt or Screw

Lubricated2

Dry3

Lubricated2

Dry3

Lubricated2

Dry3

Lubricated2

Dry3

Size

N˙m

lb-in

N˙m

lb-in

N˙m

lb-in

N˙m

lb-in

N˙m

lb-in

N˙m

lb-in

N˙m

lb-in

N˙m

lb-in

1/4

3.7

33

4.7

42

6

53

7.5

66

9.5

84

12

106

13.5

120

17

150

                         

N˙m

lb-ft

N˙m

lb-ft

5/16

7.7

68

9.8

86

12

106

15.5

137

19.5

172

25

221

28

20.5

35

26

                 

N˙m

lb-ft

N˙m

lb-ft

       

3/8

13.5

120

17.5

155

22

194

27

240

35

26

44

32.5

49

36

63

46

     

N˙m

lb-ft

N˙m

lb-ft

N˙m

lb-ft

               

7/16

22

194

28

20.5

35

26

44

32.5

56

41

70

52

80

59

100

74

 

N˙m

lb-ft

                           

1/2

34

25

42

31

53

39

67

49

85

63

110

80

120

88

155

115

9/16

48

35.5

60

45

76

56

95

70

125

92

155

115

175

130

220

165

5/8

67

49

85

63

105

77

135

100

170

125

215

160

240

175

305

225

3/4

120

88

150

110

190

140

240

175

300

220

380

280

425

315

540

400

7/8

190

140

240

175

190

140

240

175

490

360

615

455

690

510

870

640

1

285

210

360

265

285

210

360

265

730

540

920

680

1030

760

1300

960

1-1/8

400

300

510

375

400

300

510

375

910

670

1150

850

1450

1075

1850

1350

1-1/4

570

420

725

535

570

420

725

535

1280

945

1630

1200

2050

1500

2600

1920

1-3/8

750

550

950

700

750

550

950

700

1700

1250

2140

1580

2700

2000

3400

2500

1-1/2

990

730

1250

930

990

730

1250

930

2250

1650

2850

2100

3600

2650

4550

3350

Torque values listed are for general use only and are based on bolt or cap screw strength. DO NOT use these values if a different tightening procedure or torque value is given for a specific application. For plastic insert or crimped steel type lock nuts, used with stainless steel fasteners, or for nuts on U-bolts, see the tightening instructions for the specific application. Shear bolts are designed to fail under predetermined loads. Always replace shear bolts with identical grade.

Fasteners should be replaced with the same or higher grade. If higher grade fasteners are used, these should only be tightened to the strength of the original. Make sure fastener threads are clean and that you properly start thread engagement. When possible, lubricate plain or galvanized fasteners, except for lock nuts, wheel bolts or wheel nuts, unless different instructions are given for the specific application.

1 Grade 2 applies for hex cap screws (not hex bolts) up to 6 in. (152 mm in length. Grade 1 applies for hex cap screws over 6 in. (152 mm) in length, and for all other types of bolts and cap screws of any length.
2 "Lubricated" means coated with a lubricant such as engine oil, fasteners with phosphate and oil coatings or fasteners of 7/8-in. or greater with JDM F13B zinc flake coating.
3 "Dry" means plain or galvanized without any lubrication, or 1/4 to 3/4 in. fasteners with JDM F13B zinc flake coating.

TORQ1-19-20030424