Hitachi WH 18DFL Mode D'emploi page 12

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4. 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.
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.
(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.
MAINTENANCE AND INSPECTION
1. Inspecting the driver bit
Using a broken bit or one with a worn out tip is
dangerous because the bit can slip. Replace it.
2. Inspecting the mounting screws
Regularly inspect all mounting screws and ensure
that they are properly tightened. Should any of the
screws be loose, retighten them immediately. Failure
to do so could result in serious hazard.
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.
4. Cleaning of the outside
When the driver drill is stained, wipe with a soft dry
cloth or a cloth moistened with soapy water. Do not
use chloric solvents, gasoline or paint thinner, for
they melt plastics.
5. Storage
Store the driver drill in a place in which the
temperature is less than 40°C and out of reach of
children.
6. Service parts list
CAUTION:
Repair, modification and inspection of Hitachi Power
Tools must be carried out by a Hitachi Authorized
Service Center.
11
This Parts List will be helpful if presented with the
tool to the Hitachi Authorized Service Center when
requesting repair or other maintenance.
In the operation and maintenance of power tools, the
safety regulations and standards prescribed in each
country must be observed.
MODIFICATIONS:
Hitachi Power Tools are constantly being improved
and modified to incorporate the latest technological
advancements.
Accordingly, some parts may be changed without
prior notice.
GUARANTEE
We guarantee Hitachi Power Tools in accordance with
statutory/country specific regulation. This guarantee does
not cover defects or damage due to misuse, abuse, or
normal wear and tear. In case of complaint, please send
the Power Tool, undismantled, with the GUARANTEE
CERTIFICATE found at the end of this Handling
instruction, to a Hitachi Authorized Service Center.
NOTE:
Due to HITACHI's continuing program of research and
development, the specifications herein are subject to
change without prior notice.
Information concerning airborne noise and vibration
The measured values were determined according to
EN60745 and declared in accordance with ISO 4871.
Measured A-weighted sound power level: 101 dB (A)
Measured A-weighted sound pressure level: 90 dB (A)
Uncertainty KpA: 3 dB (A).
Wear hearing protection.
Vibration total values (triax vector sum) determined
according to EN60745.
Impact tightening of fasteners of the maximum capacity
of the tool:
Vibration emission value
2
Uncertainty K = 2.9 m/s
WARNING
The vibration emission value during actual use of the
power tool can differ from the declared value
depending on the ways in which the tool is used.
To identify the safety measures to protect the operator
that are based on an estimation of exposure in the
actual conditions of use (taking account of all parts of
the operating cycle such as the times when the tool is
switched off and when it is running idle in addition to
the trigger time).
a
2
h = 13.9 m/s