19
(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
di
ff
ers
with
the
diameter
of
the
bolt.
Generally
a
larger
diameter
bolt
requires
larger
tightening
torque.
(4)
Tightening
conditions
The
tightening
torque
di
ff
ers
according
to
the
torque
ratio;
class,
and
length
of
bolts
even
when
bolts
with
the
same
size
threads
are
used.
The
tightening
torque
also
di
ff
ers
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)
Tightening
torque
varies,
depending
on
the
battery’s
charge
level.
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
may
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
impact
driver
is
stained,
wipe
with
a
soft
dry
cloth
or
a
cloth
moistened
with
soapy
water.
Do
not
use
chloric
solvents,
gasoline
or
paint
thinner,
as
they
melt
plastics.
5. Storage
Store
the
impact
driver
in
a
place
in
which
the
temperature
is
less
than
40°C,
and
out
of
reach
of
children.
NOTE
Make
sure
that
the
battery
is
fully
charged
when
stored
for
a
long
period
(3
months
or
more).
The
battery
with
smaller
capacity
may
not
be
able
to
be
charged
when
used,
if
stored
for
a
long
period.
NOTE
Storing
Lithium-ion
Batteries
Make
sure
the
lithium-ion
batteries
have
been
fully
charged
before
storing
them.
Prolonged
storage
of
batteries
with
a
low
charge
may
result
in
performance
deterioration,
signi
fi
cantly
reducing
battery
usage
time
or
rendering
the
batteries
incapable
of
holding
a
charge.
However,
signi
fi
cantly
reduced
battery
usage
time
may
be
recovered
by
repeatedly
charging
and
using
the
batteries
two
to
fi
ve
times.
If
the
battery
usage
time
is
extremely
short
despite
repeated
charging
and
use,
consider
the
batteries
dead
and
purchase
new
batteries.
6. Service parts list
CAUTION
Repair,
modi
fi
cation
and
inspection
of
Hitachi
Power
Tools
must
be
carried
out
by
an
Hitachi
Authorized
Service
Center.
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
modi
fi
ed
to
incorporate
the
latest
technological
advancements.
Accordingly,
some
parts
may
be
changed
without
prior
notice.
Important notice on the batteries for the Hitachi
cordless power tools
Please
always
use
one
of
our
designated
genuine
batteries.
We
cannot
guarantee
the
safety
and
performance
of
our
cordless
power
tool
when
used
with
batteries
other
than
these
designated
by
us,
or
when
the
battery
is
disassembled
and
modi
fi
ed
(such
as
disassembly
and
replacement
of
cells
or
other
internal
parts).
NOTE
Due
to
HITACHI’s
continuing
program
of
research
and
development,
the
speci
fi
cations
herein
are
subject
to
change
without
prior
notice.
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2013/06/13 10:55:58