Makita 6918FD - Manual (Page 12)

12
• If the tool is operated continuously until the battery
cartridge has discharged, allow the tool to rest for
15 minutes before proceeding with a fresh battery.
The fastening torque is affected by a wide variety of factors
including the following. After fastening, always check the
torque with a torque wrench.
1. When the battery cartridge is discharged almost com-
pletely, 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 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 some-
what 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 reduction in
the fastening torque.
MAINTENANCE
CAUTION:
• Always be sure that the tool is switched off and the
battery cartridge is removed before attempting to
perform inspection or maintenance.
N m
80
100
120
60
40
20
0 1.0 2.0 3.0 4.0 5.0 (S)
M8
M12
M10
M10
M12
M8
Fastening time
F
astening torque
Proper f
astening torque
.
(ft lbs) .
(87)
(72)
(58)
(43)
(28)
(14)
(5/16")
(5/16")
(3/8")
(3/8")
(1/2")
(1/2")
High tensile bolt
002360