Operators Manual

6
Holding the tool
Hold the tool only by the handle when performing an
operation. Do not touch the metal part.
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 the figures.
Standard bolt
Fastening torque (N m)
Fastening time (S)
.
009632
High tensile bolt
Fastening torque(N m)
Fastening time (S)
.
200
150
100
50
0
0 0.5 1.0 1.5 2.0 2.5 3.0
M12x80
M10x80
M12
M10
M8x80
M8
M14x80
250
M14
009633
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 M10 or smaller, carefully
adjust pressure on the switch 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 over than M10, perform the above test
operation to prevent the trouble on socket or bolt,
etc.
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.
MAINTENANCE
CAUTION:
• Always be sure that the tool is switched off and
unplugged before attempting to perform inspection
or maintenance.
• Never use gasoline, benzine, thinner, alcohol or the
like. Discoloration, deformation or cracks may
result.