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
Fastening time (S)
High tensile bolt
Fastening time (S)
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.
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
If you use a spare battery to continue the operation,
rest the tool at least 15 min.
The fastening torque is affected by a wide variety of
factors including the following. After fastening, always
check the torque with a torque wrench.
When the battery cartridge is discharged almost
completely, voltage will drop and the fastening
torque will be reduced.
Driver bit or socket bit
Failure to use the correct size driver bit or socket
bit will cause a reduction in the fastening torque.
Even though the torque coefficient and the
class of bolt are the same, the proper fastening
torque will differ according to the diameter of
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.
The manner of holding the tool or the material of
driving position to be fastened will affect the torque.
Operating the tool at low speed will cause a
reduction in the fastening torque.
Always be sure that the tool is switched off and the
battery cartridge is removed before attempting to
perform inspection or maintenance.
Never use gasoline, benzine, thinner, alcohol or the
like. Discoloration, deformation or cracks may