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Screw on nuts, and tighten bolts in the manner and sequence below.
Figure 3-
Tightening Sequence
Bring the parts of the joint into full contact by tightening sufficient bolts to achieve a “snug-tight”
condition. The “snug-tight” condition is 10% of the bolt’s full tension or yield tension. This is achieved to
reasonable accuracy and repeatability by the full effort of an average man (approximately 70kg) using a standard
podger spanner, or by a few impacts from an impact wrench, after initial slackness in the nut has been taken up.
Make corresponding permanent marks on the nut and the protruding thread of the bolt, from which subsequent
rotation of the nut or bolt can be measured. Then using the appropriate turns in Figure 3, turn the bolts/nuts,
according to the tightening sequence shown in Figure 3, if appropriate, to achieve 70% of yield tension in the
bolts.
Bolt Size (mm)
Shank Length Between
Load Faces Of Bolt and
Nut (mm)
Final Torsional Displacement
Between Bolt and Nut (turns)
M16 – M22
<120
>120
0.5
0.75
M24 – M36
<160
>160
0.5
0.75
M38 – M64
<200
>200
0.5
0.75