Hitachi WR12DMB - 12.0 V 1/2" Impact Wrench 2 Battery Service Manual page 15

*The data above are intended for reference purposes only because actual loosening torque will vary
depending on tightening conditions.
(3) Sinking time comparison (square washers)
Figure 3 shows the time required for tightening an M12 bolt into a pine laminated lumber of 105 mm square
until the square washers at both sides are sunk into the lumber by 1.3 mm respectively. The Model WR 12DM
can tighten strap bolts and corner bracings (used in Japanese wooden buildings) speedily as it can sink
washers into a workpiece quickly.
*The data above are intended for reference purposes only because actual time required for sinking
washers will vary depending on tightening conditions.
The 30% higher power motor and the 35% larger hammer are the main factors that increase the tightening
torque of the Model WR 12DM substantially. Comparison of hammer and number of strokes are shown below.
9
8
7.4
7
6
4.6
5
4
3
2
1
0
WR 12DM WR 12DH
Fig. 2
9
8.1
8
7
6
5
4
3.2
3
2
1
0
WR 12DM WR 12DH
Fig. 3
8.1
C
8.3
C
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