TORQUE-."That Which Produces Rotation or Torsion" Back

The amount of twisting force (torque) on a bolt or screw is normally measured by the use of a torque wrench.

The correct tightening of bolts is one of the most singularly important operations done when repairing an engine or component.

Correct torque can eliminate deformation of mating surfaces, cylinder head to the block, intake and exhaust manifold to the block, main bearing caps to the block, rod caps to the connecting rod to mention a few of the very critical areas. It can also eliminate bolt breakage, thread stripping, water and oil leaks.

Virtually every bolt and screw on an engine or component has a torque specification for correct tightening. It is imperative that the manufacturer's recommendation be followed for correct tightening sequence and tightness to eliminate problems created by bolts and screws being too tight or too loose.

S.A.E. BOLT GRADE AND RECOMMENDED TORQUE CHART

S.A.E.
GRADE

1 or 2

5

6

8

RECOMMENDED FOR COMPETITION AND CRITICAL USE

p22a.gif (1273 bytes) p22b.gif (1303 bytes) p22c.gif (1307 bytes) p22d.gif (1370 bytes) p22e.gif (1454 bytes)
1/4 DIA

5 Ft. lbs

7 Ft. lbs

10 Ft. Ibs

10.5 Ft. lbs

11 Ft. lbs

5/16

9

14

19

22

24

3/8

15

25

34

37

40

7/16

24

40

55

60

65

1/2

37

60

85

92

97

9/16

53

88

120

132

141

5/8

74

120

167

180

192

3/4

120

220

280

286

316

7/8

190

302

440

473

503

1

282

466

660

714

771

  (P21-22)