English
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8. Tightening and loosening bolts
A hex. socket matching the bolt or nut must
fi
rst be selected. Then mount the socket on the
anvil, and grip the nut to be tightened with the hex. socket. Holding the tool in line with the
bolt, press the power switch to impact the nut for several seconds.
If the nut is only loosely
fi
tted to the bolt, the bolt may turn with the nut, therefore mistaking
proper tightening. In this case, stop impact on the nut and hold the bolt head with a wrench
before restarting impact, or manually tighten the bolt and nut to prevent them slipping.
OPERATIONAL CAUTIONS
1. Resting the unit after continuous work
After use for continuous bolt-tightening work, rest the unit for 15 minutes or so when
replacing the battery. The temperature of the motor, switch, etc., will rise if the work is
started again immediately after battery replacement, eventually resulting in burnout.
NOTE
Do not touch the metal parts, as it gets very hot during continuous work.
2. Cautions on use of the speed control switch
This switch has a built-in, electronic circuit which steplessly varies the rotation speed.
Consequently, when the switch trigger is pulled only slightly (low speed rotation) and the
motor is stopped while continuously driving in screws, the components of the electronic
circuit parts may overheat and be damaged.
3. Use a tightening time suitable for the screw
The appropriate torque for a screw di
ff
ers according to the material and size of the screw,
and the material being screwed etc., so please use a tightening time suitable for the screw.
In particular, if a long tightening time is used in the case of screws smaller than M8, there
is a danger of the screw breaking, so please con
fi
rm the tightening time and the tightening
torque beforehand.
4. Work at a tightening torque suitable for the bolt under impact
The optimum tightening torque for nuts or bolts di
ff
ers with material and size of the nuts
or bolts. An excessively large tightening torque for a small bolt may stretch or break the
bolt. The tightening torque increases in proportion to the operation time. Use the correct
operating time for the bolt.
5. Holding the tool
Hold the tool
fi
rmly with both hands. In this case hold the tool in line with the screw or bolt.
It is not necessary to push the tool very hard. Hold the tool with a force just su
ffi
cient to
counteract the impact force.
6. Con
fi
rm the tightening torque
The following factors contribute to a reduction of the tightening torque. So con
fi
rm the
actual tightening torque needed by screwing up some bolts before the job with a hand
torque wrench. Factors a
ff
ecting the tightening torque are as follows.
(1) Voltage
When the discharge margin is reached, voltage decreases and tightening torque is
lowered.
(2) Operating
time
The tightening torque increases when the operating time increases. But the tightening
torque does not increase above a certain value even if the tool is driven for a long time.
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