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6-3. Tightening Torque
6-3-1. Tightening torque characteristic comparisons
(1) Impact driver
Thanks to the high-power rare-earth magnet motor and the computer analysis, the Model WH 9DM gives
optimum impact at tightening screws and the tightening torque is increased.
Fig. 1-1
Fig. 1-2
Test conditions
Bolt: M12 x 45 mm (15/32" x 1-3/4")
(strength grade: 12.9)
Steel plate: Mild steel
M12 (15/32") Thickness = 25 mm (1")
Accessory tool: Hexagon socket ass'y
(2) Impact wrench
The Model WR 9DM has lower tightening torque than the Model WR 8DH (square dimension 12.7 mm (1/2 "))
because the square drive dimension is 9.5 mm (3/8 ").
Test conditions
Bolt: M12 x 45 mm (15/32" x 1-3/4")
(strength grade: 12.9)
Steel plate: Mild steel
M12 (15/32") Thickness = 25 mm (1")
Accessory tool: Hexagon socket ass'y
WH 9DM
WH 8DH
200
(174 in-lbs.)
0
1
2
3
400
(347 in-lbs.)
600
(521 in-lbs.)
800
(694 in-lbs.)
1000
(868 in-lbs.)
kgf
•
cm
Tightening time
Tightening torque
C (forward)
1200
(1042 in-lbs.)
N
•
m
120
100
80
20
40
60
0
0
0
(sec.)
WR 8DH
WR 9DM
200
(174 in-lbs.)
0
1
2
3
400
(347 in-lbs.)
600
(521 in-lbs.)
800
(694 in-lbs.)
1000
(868 in-lbs.)
kgf
•
cm
Tightening time
Tightening torque
1200
(1042 in-lbs.)
N
•
m
120
100
80
20
40
60
0
0
0
(sec.)
