6
OPERATION
The proper fastening torque may differ depending upon
the kind or size of the bolt, the material of the workpiece
to be fastened, etc. The relation between fastening
torque and fastening time is shown in Fig. 4 and Fig. 5.
Hold the tool firmly and place the socket over the bolt or
nut. Turn the tool on and fasten for the proper fastening
time.
NOTE:
• When fastening screw M12 or smaller, carefully adjust
pressure on the switch trigger so that the screw is not
damaged.
• Hold the tool pointed straight at the bolt or nut without
applying excessive pressure on the tool.
• If you fasten the bolt for a time longer than shown in the
figures, the bolt or the socket may be overstressed,
damaged, etc. Before starting your job, always perform
a test operation to determine the proper fastening time
for your bolt. Especially for the bolt other than M12, per-
form the above test operation to prevent the trouble on
socket or bolt, etc.
The fastening torque is affected by a wide variety of fac-
tors including the following. After fastening, always check
the torque with a torque wrench.
1. Voltage
• Voltage drop will cause a reduction in the fastening
torque.
2. Socket
• Failure to use the correct size socket will cause a
reduction in the fastening torque.
• A worn socket (wear on the hex end or square
end) will cause a reduction in the fastening torque.
3. Bolt
• Even though the torque coefficient and the class of
bolt are the same, the proper fastening torque will
differ according to the diameter of the bolt.
• Even though the diameters of bolts are the same,
the proper fastening torque will differ according to
the torque coefficient, the class of bolt and the bolt
length.
4. The use of the universal joint or the extension bar
somewhat reduces the fastening force of the impact
wrench. Compensate by fastening for a longer
period of time.
5. The manner of holding the tool or the material of
driving position to be fastened will affect the torque.
MAINTENANCE
CAUTION:
Always be sure that the tool is switched off and
unplugged before attempting to perform inspection or
maintenance.
Replacing carbon brushes
Remove and check the carbon brushes regularly.
Replace when they wear down to the limit mark. Keep
the carbon brushes clean and free to slip in the holders.
Both carbon brushes should be replaced at the same
time. Use only identical carbon brushes. (Fig. 6)
Use a screwdriver to remove the brush holder caps. Take
out the worn carbon brushes, insert the new ones and
secure the brush holder caps. (Fig. 7)
To maintain product SAFETY and RELIABILITY, repairs,
any other maintenance or adjustment should be per-
formed by Makita Authorized or Factory Service Centres,
always using Makita replacement parts.
ACCESSORIES
CAUTION:
These accessories or attachments are recommended for
use with your Makita tool specified in this manual. The
use of any other accessories or attachments might
present a risk of injury to persons. Only use accessory or
attachment for its stated purpose.
If you need any assistance for more details regarding
these accessories, ask your local Makita service center.
• Sockets
• Extension bar
• Universal joint
