Metabo HPT WR36DA Manual página 18

English
Low 1 mode
Rotation speed 0 – 600 /min
For work that requires fi ne adjustments such as
when tightening small diameter bolts.
Use
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. Work at a tightening torque suitable for the bolt under
impact
The optimum tightening torque for nuts or bolts
diff ers 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.
4. Holding the tool
Hold the tool fi rmly with both hands. In this case hold
the tool in line with the bolt.
It is not necessary to push the tool very hard. Hold the
tool with a force just suffi cient to counteract the impact
force.
18
Examples of tightening mode selector function settings
Low 2 mode
0 – 900 /min
Medium mode
0 – 1,200 /min
For work that requires
the power to be
suppressed during
tightening.
5. Confi rm the tightening torque
The following factors contribute to a reduction of the
tightening torque. So confi rm the actual tightening
torque needed by screwing up some bolts before the
job with a hand torque wrench. Factors aff ecting 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 diff ers with the diameter of the
bolt. Generally a larger diameter bolt requires larger
tightening torque.
(4) Tightening conditions
The tightening torque diff 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 diff 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) Using optional parts
The tightening torque is reduced a little when an
extension bar, universal joint or a long socket is used.
(6) Clearance of the socket
A worn or deformed hex. or a square-holed socket will
not give an adequate tightness to the fi tting between
the nut or anvil, consequently resulting in loss of
tightening torque.
Using an improper socket which does not match to the
bolt will result in an insuffi cient tightening torque.
(7) Tightening torque varies, depending on the battery's
charge level.
High mode
0 – 1,500 /min
For work that requires
power and speed
during tightening.