Makita BTW253 Manuel D'instruction page 6

OPERATION
CAUTION:
Always insert the battery cartridge all the way until
•
it locks in place. If you can see the red part on the
upper side of the button, it is not locked completely.
Insert it fully until the red part cannot be seen. If not,
it may accidentally fall out of the tool, causing injury
to you or someone around you.
Hold the tool firmly and place the socket over the bolt or
nut. Turn the tool on and fasten for the proper fastening
time.
008666
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
.
N m
140
(101)
(ft.lbs)
120
(87)
100
(72)
80
(58)
60
(43)
40
(29)
20
(14)
0
Fastening time
008669
M14(9/16")
M12(1/2")
M14(9/16")
M10(3/8")
M12(1/2")
M10(3/8")
1.0 2.0 3.0
(S)
High tensile bolt
.
N m
(ft.lbs)
140
(101)
120
(87)
100
(72)
80
(58)
60
(43)
40
(29)
20
(14)
0
008670
NOTE:
Hold the tool pointed straight at the bolt or nut.
•
Excessive fastening torque may damage the
•
bolt/nut or socket. Before starting your job, always
perform a test operation to determine the proper
fastening time for your bolt or nut.
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
cartridge.
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
completely, 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
somewhat reduces the fastening force of the
impact wrench. Compensate by fastening for a
longer period of time.
6
M12(1/2")
M12(1/2")
M10(3/8")
M10(3/8")
M8(5/16")
M8(5/16")
(S)
3.0 4.0 5.0
1.0 2.0
Fastening time