Operation, Standard bolt – Makita 6918D User Manual
Page 9
9
OPERATION
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 fas-
tening time is shown in the figures.
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 M8 (5/16”) or smaller, carefully
adjust pressure on the switch trigger so that the screw is
not damaged.
•
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. Especially for the bolt smaller than M8
(5/16”), perform the above test operation to prevent the
trouble on socket or bolt, etc.
•
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. 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.
N m
80
100
60
40
20
0
1.0
2.0
3.0
(S)
M14
M12
M10
M10
M12
M14
F
astening torque
Fastening time
Proper f
astening torque
.
(ft lbs)
.
(72)
(58)
(43)
(29)
(14)
(9/16")
(9/16")
(1/2")
(1/2")
(3/8")
(3/8")
Standard bolt
002359
N m
80
100
120
60
40
20
0
1.0
2.0
3.0
4.0
5.0
(S)
M8
M12
M10
M10
M12
M8
Fastening time
F
astening torque
Proper f
astening torque
.
(ft lbs)
.
(87)
(72)
(58)
(43)
(28)
(14)
(5/16")
(5/16")
(3/8")
(3/8")
(1/2")
(1/2")
High tensile bolt
002360