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○Tightening Torque may differ by conditions.
Torque setting has to be done daily before operation and when tightening
conditions change.
○Turn off the motor before set target torque.
○In order to prevent malfunction as well as over torque, never tightening the
same bolts / nuts twice.
2.Tendencies that tightening torque may differ.
Tightening torque varies depending on tightening conditions.
Tendency shown as below.
Factors at Tightening Conditions
Possibility
- When connection is soft (gasket, rubber, glass & etc in
between the steels)
- When bolt length is extremely long,
- When bolt diameter is small.
- When bolt grades are under 8.8 or 10.9
- When friction coefficient of the bolt is high
- When bolt or washer is stripped during tightening
Tightening Torque
becomes Low
- When connection is hard
- When bolt diameter is large
- When bolt length is short
- When water or oil is adhered on the bolt
- When tightened bolt is tightened again (over tightened)
- When voltage is lower than rated voltage of the wrench
Tightening Torque
becomes High
- When gaps between the connection is large
- When Tightening bolts/nuts from tilt position
Result in imprecise
tightening
Summary of Contents for GNR121E-UC
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