11
OPERATION
The proper fastening torque may differ depending upon the
kind or size of the screw/bolt, the material of the workpiece to
be fastened, etc. The relation between fastening torque and
fastening time is shown in the figures.
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 and turn the tool on to
start operation.
NOTE:
• Use the proper bit for the head of the screw/bolt that you
wish to use.
• When fastening screw M8 or smaller, carefully adjust
pressure on the switch trigger so that the screw is not
damaged.
• Hold the tool pointed straight at the screw.
• If you tighten the screw for a time longer than shown in
the figures, the screw or the point of the driver bit may be
overstressed, stripped, damaged, etc. Before starting
your job, always perform a test operation to determine
the proper fastening time for your screw.
• 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. Driver bit or socket bit
Failure to use the correct size driver bit or socket bit 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.
0
M8(5/16”)
M6(1/4”)
0.5 1.0
Machine screw
N.m(ft.lbs)
20
(15)
15
(11)
10
(7)
5
(4)
M8
M6
(S)
Fastening torque
Proper fastening torque
Fastening time
002836
M12
M10
M8
3.0
1.0 2.0
Standard bolt
N.m
(ft.lbs)
80
(57)
60
(43)
40
(29)
20
(15)
(S)
M12(1/2”)
M10(3/8”)
M8(5/16”)
Fastening torque
Proper fastening torque
Fastening time
002837