Metabo HPT WR 18DH Manual De Instrucciones página 18

English
CAUTION
Do not touch the hammer case 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 trigger switch 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. Work at a tightening torque suitable for the bolt under
impact
The optimum tightening torque for nuts or bolts differs
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.
4. Holding the tool
Hold the tool firmly with both hands. In this case hold
the tool in line with the bolt.
It is not necessary to push the tool very hard. Hold the
tool with a force just sufficient to counteract the
impact force.
5. Confirm the tightening torque
The following factors contribute to a reduction of the
tightening torque. So confirm the actual tightening
torque needed by screwing up some bolts before the
job with a hand torque wrench. Factors affecting the
tightening torque are as follows.
WARNING
Be sure to turn off the switch and pull out the
battery before doing any inspection or
maintenance.
1. Checking the condition of the socket
A worn or deformed hex. or a square-holed socket will
not give an adequate tightness to the fitting between
the nut or anvil, consequently resulting in loss of
tightening torque. Pay attention to wear of a socket
holes periodically, and replace with a new one if
needed.
18
MAINTENANCE AND INSPECTION
(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.
(3) Diameter of bolt
The tightening torque differs with the diameter of the
bolt. Generally a larger diameter bolt requires larger
tightening torque.
(4) Tightening conditions
The tightening torque differs according to the torque
ratio; class, and length of bolts even when bolts with
the same size threads are used. The tightening torque
also differs according to the condition of the surface
of workpiece through which the bolts are to be
tightened. When the bolt and nut turn together, torque
is greatly reduced.
(5) Using optional parts
The tightening torque is reduced a little when an
extension bar, universal joint or a long socket is used.
(6) Clearance of the socket
A worn or deformed hex. or a square-holed socket will
not give an adequate tightness to the fitting between
the nut or anvil, consequently resulting in loss of
tightening torque.
Using an improper socket which does not match to
the bolt will result in an insufficient tightening torque.
(7) Tightening torque varies, depending on the battery's
charge level.
2. Check the Screws
Loose screws are dangerous. Regularly inspect them
and make sure they are tight.
CAUTION
Using this power tool with loosened screws is
extremely dangerous.
3. Maintenance of the motor
The motor unit winding is the very "heart" of the power
tool.
Exercise due care to ensure the winding does not
become damaged and/or wet with oil or water.