Hitachi Koki WR 12DM2 Manual De Instrucciones página 20

English
12. Tightening and loosening bolts
A hex socket matching the bolt or nut must first be selected. Then mount the socket on
the anvil, and grip the nut to be tightened with the hex socket. Holding the wrench in
line with the bolt, press the power switch to impact the nut for several seconds.
If the nut is only loosely fitted to the bolt, the bolt may turn wit 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.
13. Number of bolt tightened possible (WR12DM2)
Please refer to the table below for the number of bolt tightened possible with one
charge.
<WR12DM2> (EB1220BL)
15/32" × 1–3/4" (M12 × 45) High tension bolt
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.
CAUTION:Do not touch the protector, 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. 17 and 18 for the tightening torque of bolts (according to size), under the
conditions shown in Fig. 19. 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 end 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 5/16" (8 mm), there is a danger of the screw breaking, so please confirm the
tightening time and the tightening torque beforehand.
20
Bolt used No. of tightenings
Approx. 120