Operational Cautions - Hitachi WR 12DM Manual De Instrucciones

8. 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.
9. Number of bolt tightened possible
Please refer to the table below for the number of bolt tightened possible with one charge.
<For WR12DM> (EB1220BL)
5/8" × 2–5/32" (M16 × 55) F10T bolt
<For WR9DM> (EB9B)
Ordinary bolt 15/32" × 1–3/4" (M12 × 45)
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 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 and 13 for the tightening torque of bolts (according to size), under the
conditions shown in Fig. 14. Please use this example as a general reference, as tightening
torque will vary according to tightening conditions.
Tightening torque varies, depending on the battery's charge level. Fig. 15 and 16 shows
an example of the relationship between tightening torque and the number of tightenings
(WR12DM and WR9DM). As shown, tightening torque gradually weakens with the
increase in the number of tightenings. In particular, as the torque decreases very close
to the complete discharge ("a" margin in graph), the unit's impact weakens, the number
of time impacts declines and tightening torque drops off abruptly. If this occurs, check
torque level, then recharge the battery if necessary.
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Bolt used
Bolt used
English
No. of tightenings
Approx. 90
No. of tightenings
Approx. 90
17