Hitachi WH9DM2, WR9DM2, WR12DM2, WH12DM2 instruction manual Kgf·cm In-lbs 100 1000

English

(6)Clearance of the socket (WR12DM2, WR9DM2)

A worn or deformed hex. or a square-holed socket will not give an adequate tightness to the fitting between the nut or anvil, consequently resulting in loss of tightening torque.

Using an improper socket which does not match to the bolt will result in an insufficient tightening torque. Matching socket and bolt sizes are shown in Table 4, 5, 6 and 7.

(7)Tightening torque varies, depending on the battery’s charge level (WR12DM2, WR9DM2) Fig. 22 and 23 show an example of the relationship between tightening torque and the number of tightenings. As shown, tightening torque gradually weakens with the increase in the number of tightenings. In particular, as the torque decreases very close to the complete discharge (“a” margin in graph), the unit’s impact weakens, the number of time impacts declines and tightening torque drops off abruptly. If this occurs, check torque level, then recharge the battery if necessary.

<For WH12DM2>

kgf·cm

	(in-lbs)		N·m
			100
	1000
torque	(868)
	800	80
Tightening	(695)
	600	60
	(521)
	400	40
	(347)
	200	20
	(174)
	0	0

3/8"⋅1-5/32"

(M10⋅30)

High strength bolt

Ordinary bolt

0 1 2 3

Tightening torque

kgf·cm		N·m		15/32"⋅1-3/4"
(in-lbs)				(M12⋅45)
		140
1400
			High strength bolt
(1215)
1200		120
(1042)
1000	100
(868)
				Ordinary bolt

80080

(694)

60060

(521)

40040

(347)

20020

(174)

0		0
			1	2	3
	0

	kgf·cm		N·m
	(in-lbs)
			140
	1400
	(1215)
	1200		120
	(1042)
torque	1000		100
	(868)
	800		80
Tightening	(694)
	400	40
	600		60
	(521)
	(347)
	200		20
	(174)
	0		0
		0

9/16"⋅1-15/16"

(M14⋅50)

High strength bolt

Ordinary bolt

1 2 3

Tightening	time: sec	Tightening	time: sec	Tightening	time: sec
(Steel plate	thickness	(Steel plate	thickness	(Steel plate	thickness
t = 3/8" (10 mm))		t = 1" (25 mm))		t = 1" (25 mm))

Fig. 17

23