Makita 6918FD Instruction Manual page 6

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. When the battery cartridge is discharged almost
completely, voltage will drop and the fastening
torque will be reduced.
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.
6. Operating the tool at low speed will cause a reduc-
tion in the fastening torque.
MAINTENANCE
CAUTION:
• Always be sure that the tool is switched off and the bat-
tery cartridge is removed before attempting to perform
inspection or maintenance.
Replacing carbon brushes (Fig. 9 & 10)
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.
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.
To maintain product SAFETY and RELIABILITY, repairs,
any other maintenance or adjustment should be per-
formed by Makita Authorized Service Centers, 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
• Bit adapter
• Screw bits
• Various type of Makita genuine batteries and chargers
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