Makita 6904VH Instruction Manual page 7

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. 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
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.
Standard bolt
For 6905H
.
N m
.
(ft lbs)
M20X50
200
(2040)
M16X50
150
(1530)
100
(1020)
M12X50
50
(510)
0 0.5 1
Fastening time
005303
M20
M16
M12
1.5
(S)
High tensile bolt
.
N m
.
(kg cm)
300
(3060)
250
(2550)
200
(2040)
150
(1530)
M12X50
100
(1020)
50
(510)
0 1 2 3
Fastening time
005304
Screwdriving operation
002371
For 6904VH only
When driving screws, install a bit adapter (optional
accessory) on the tool and insert a driver bit (optional
accessory) into the bit adapter.
Hold the tool firmly and place the point of the driver bit in
the screw head. Apply forward pressure to the tool to the
extent that the bit will not slip off the screw. Start the tool
slowly and then increase the speed gradually. Release
the switch trigger just as the screw bottoms out.
NOTE:
Use the proper bit for the head of the screw/bolt
•
that you wish to use.
Hold the tool pointed straight at the screw or the
•
screw and/or bit may be damaged.
When driving wood screws, predrill pilot holes to
•
make driving easier and to prevent splitting of the
workpiece. The pilot holes should be slightly
smaller than the wood screws in diameter.
7
For 6905H
M16X50
M16
M12
8
4 5 6 7
(S)