Carter CT08 - Page 36

Check the bolts and nuts for tightening torque
……every 250 h (Originally for every day)
Check the tightness for every day and then every 250 h. Tighten it to the set torque if needed. Replace it with bolts
and nuts with same or higher grade.
Important: please use the torque wrench to check the torques of bolts and nuts!
Metric bolts and nuts
Thread dimensions
Standard torque (N.m)
Thread dimensions
Standard torque (N.m)
M6
12±3
M14
160±30
M8
28±7
M16
240±40
M10
55±10
M20
460±60
M12
100±20
M30
1600±200
2. Torque of main components: (N.m)
Thread dimensions
Recommended torque
M12 bolts fixing the traveling motor
120±10
M16 bolts fixing the slewing bearing
325 ±15
M16 bolts fixing the swing mechanism
325 ±15
Important:
1. Before installed, the bolts and nuts should be cleaned.
2. Grease the bolts and the nuts (such as the white zinc b able to be dissolved to lubricant), so as to stabilize
their abrasion coefficient.
3. The counterweight bolts should be kept tightened up.
Caution: all the tightening torques should be expressed with kgf.m.
For example: use a wrench with 1m long to tighten the bolts and nuts, and apply 12kgf of force to the end of
wrench, generating the following torque:
1m×12kgf=12kgf.m
To generate the same torque with 0.25m wrench: 0.25m×y=12kgf.m
Needed force: y=12kgf.m／0.25m=48kgf
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