Tightening Torque - Hitachi WH 9DM Technical Data And Service Manual

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.
N m
•
kgf cm
•
120
1200
(1042 in-lbs.)
100
1000
(868 in-lbs.)
80
800
(694 in-lbs.)
60
600
(521 in-lbs.)
40
400
(347 in-lbs.)
20
200
(174 in-lbs.)
0
0
0
(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 ").
N m
•
kgf cm
•
120
1200
(1042 in-lbs.)
100
1000
(868 in-lbs.)
80
800
(694 in-lbs.)
60
600
(521 in-lbs.)
40
400
(347 in-lbs.)
200 20
(174 in-lbs.)
0
0
0
WH 9DM
1
2
0
Tightening time
Fig. 1-1
WR 8DH
2
0 1
Tightening time
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
WH 8DH
C (forward)
(sec.)
3
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
WR 9DM
3
(sec.)
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