Operational Cautions - Hitachi WH 14DBL Bedienungsanleitung

7. Tightening and loosening screws
Install the bit that matches the screw, line up the bit
in the grooves of the head of the screw, then tighten
it.
Push the impact driver just enough to keep the bit
fitting the head of the screw.
CAUTION:
Applying the impact driver for too long tightens the
screw too much and can break it.
Tightening a screw with the impact driver at an angle
to that screw can damage the head of the screw and
the proper force will not be transmitted to the screw.
Tighten with this impact driver lined up straight with
the screw.
8. Number of screws tightenings possible
Please refer to the table below for the number of
screw tightened possible with one charge.
Screw used
Wood screw ø4 × 50
(Soft wood)
Machine screw M8 × 16
These values may vary slightly, according to
surrounding temperature and battery characteristics.

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.
kgf·cm N·m
1400
1200
1000
800
600
400
200
0
Battery
BSL1430
Approx. 1170
Approx. 2590
M12 × 45
140
120
100
High tension
bolt
80
60
Ordinary bolt
40
20
0
0 1 2 3
Tightening time: sec.
(Steel plate thickness
t = 25 mm)
NOTE:
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 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. Tightening torque
Refer to Fig. 12 the tightening torque of bolts
(according to size), under the conditions shown in
Fig. 13. Please use this example as a general reference,
as tightening torque will vary according to tightening
conditions.
NOTE:
If a long striking time is used, screws will be strongly
tightened. This may cause the screw to break, or may
damage the tip of the bit.
If the unit is held at an angle to the screw being
tightened, the head of the screw may be damaged, or
the specified torque may not be transmitted to the
screw. Always keep the unit and the screw being
tightened in a straight line.
4. Use a tightening time suitable for the screw
The appropriate torque for a screw differs 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
confirm the tightening time and the tightening torque
beforehand.
kgf·cm
1600
1400
1200
1000
800
600
400
200
0
Fig. 12
English
N·m
M14 × 50
160
140
120
High tension
bolt
100
80
60 Ordinary bolt
40
20
0
0 1 2 3
Tightening time: sec.
(Steel plate thickness
t = 25 mm)
12