Hitachi WH 9DM2 Manual

TECHNICAL DATA
AND
SERVICE MANUAL
CORDLESS IMPACT DRIVER
WH 9DM2
CORDLESS IMPACT WRENCH
WR 9DM2
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST Nos. WH 9DM2: G801
WR 9DM2: G802
Mar. 2004
G
MODELS
WH 9DM2
WH 9DM2 WR 9DM2
WR 9DM2
Hitachi 
Power Tools

REMARK:
Throughout this TECHNICAL DATA AND SERVICE MANUAL, a symbol(s)
is(are) used in the place of company name(s) and model name(s) of our
competitor(s). The symbol(s) utilized here is(are) as follows:
Symbol Utilized
Competitor
Company Name Model Name
CMAKITA BTD061
WH 9DM2
Symbol Utilized
Competitor
Company Name Model Name
CMAKITA 6991D
WR 9DM2

Page
CONTENTS
1. PRODUCT NAME ...........................................................................................................................1
2. MARKETING OBJECTIVE .............................................................................................................1
3. APPLICATIONS ..............................................................................................................................1
4. SELLING POINTS ..........................................................................................................................2
4-1. Selling Point Descriptions .............................................................................................................. 4
5. SPECIFICATIONS ..........................................................................................................................7
5-1. Specifications ................................................................................................................................. 7
5-2. Optional Accessories ..................................................................................................................... 9
6. COMPARISONS WITH SIMILAR PRODUCTS ............................................................................12
6-1. Specification Comparisons (Cordless Impact Driver) .................................................................. 12
6-2. Specification Comparisons (Cordless Impact Wrench) ............................................................... 13
6-3. Tightening Torque ........................................................................................................................ 14
6-4. Tightening Speed ......................................................................................................................... 17
6-5. Number of Screws or Bolts Driven ............................................................................................... 18
7. PRECAUTIONS IN SALES PROMOTION ...................................................................................19
7-1. Safety Instructions ....................................................................................................................... 19
7-2. Tightening Torque Inspection Prior to Operation ......................................................................... 21
7-3. Tightening Torque Variation ......................................................................................................... 21
7-4. Suggestions and Precautions for the Efficient Use of the Charger .............................................. 22
8. OTHER PRECAUTIONS ..............................................................................................................23
9. REPAIR GUIDE ............................................................................................................................24
9-1. Precautions in Disassembly and Reassembly ............................................................................. 24
9-2. Precautions in Disassembly and Reassembly of Battery Charger .............................................. 33
10. STANDARD REPAIR TIME (UNIT) SCHEDULES .....................................................................34
Assembly Diagram for WH 9DM2
Assembly Diagram for WR 9DM2

--- 1 ---
1. PRODUCT NAME
Hitachi Cordless Impact Driver, Model WH 9DM2
Hitachi Cordless Impact Wrench, Model WR 9DM2
2. MARKETING OBJECTIVE
The new cordless impact driver Model WH 9DM2 ("Super Impact 9") and the new cordless impact wrench Model
WR 9DM2 ("Super Wrench 9") are brought out as DC 9.6 V products of the Super Impact series. They are
upgraded versions of the current Models WH 9DM and WR 9DM, developed to expand the market share and the
sales.
The new Model WH 9DM2 provides the lower maximum tightening torque 80 N•m than that of the current Model
WH 9DM (95 N•m). This is to realize a lightweight and compact driver (overall length 20 mm, product weight
200 g). The Model WH 9DM2 is very convenient for tightening small screws such as sash screws requiring less
tightening torque.
The new Model WR 9DM2 provides the class-top tightening torque 120 N•m that is 40% higher than the current
Model WR 9DM.
3. APPLICATIONS
•Tightening/loosening of small screws, tapping screws, wood screws, bolts, nuts, etc.
•Drilling into wood and various other materials (with use of optional accessory drill chuck adapter).
[Applicable Markets]
•Wood-product assembly: Tightening/loosening of wood screws, lag bolts, etc.
•Construction industry: Assembly of scaffolding, roofing, aluminum sashes, fencing, etc.; removal of plastic cones
from concrete forms, mounting/removal of form ties; drilling into the wood frames of concrete forms, etc.
•Manufacturing industry: Assembly work for automobiles, rolling stock, shipbuilding, agricultural machinery and
tools, industrial machines, steel furniture, etc.
•Utility industry: Assembly and installation of electric equipment, plumbing facilities, air conditioning (duct
assembly, etc.), sanitary fixtures and various other facilities.
•Service industry: General repair work; installation of advertising signs, automobile repair, assembly of garages
and carports storage sheds, etc.
•Various other assembly, construction or repair facilities.

--- 2 ---
Selling points common to the Model
WH 12DM2
New design
Elastomer is new titanium silver color.
Protector is standard.
Convenient light equipped hook
High durability, dust resistance and
long service life
Advanced case (excellent
accommodation)
4. SELLING POINTS
(1) Cordless impact driver Model WH 9DM2
The shortest overall length in the class
147 mm
Convenient for work in narrow places
Lightweight 1.2 kg
Easy to operate for a long time
Easily portable
30% lower striking start torque
Optimum for light-duty works such as
tightening sash screws, plastic screws
and Teks screws

--- 3 ---
(2) Cordless impact wrench Model WR 9DM2
9.5 mm (3/8")
(Reference) WR 12DM2: 12.7 mm (1/2")
Selling points common to the Model
WR 12DM2
New design
Elastomer is new titanium silver color.
Protector is standard.
Convenient light equipped hook
High durability, dust resistance and
long service life
Advanced case (excellent
accommodation)
Class-top tightening torque
120 N•m {1220 kgf•cm}
C: 100 N•m
Compact
Overall length 160 mm
C: 168 mm

--- 4 ---
4-1. Selling Point Descriptions
Refer to pages 4 through 10 of Technical Data Service Manual for the Models WH 12DM2/WR 12DM2 for
common selling points.
Model WH 9DM2
(1) The shortest overall length in the class 147 mm / light weight 1.2 kg
To realize a lightweight and compact driver, the Model WH 9DM2 provides the lower maximum tightening
torque 80 N•m than that of the current Model WH 9DM (95 N•m).
Comparison of the armature
Comparison of the decelerating unit
WH 9DM2 WH 9DM C
Product Unit
Overall length mm
Weight g
Hitachi
WH 9DM2
22.6 (57/64")
30 (0.066 lbs.)
Hitachi
WH 9DM
25.2 (63/64")
53 (0.117 lbs.)
C
25.5 (1")
44 (0.097 lbs.)
1
2
Equipped with a new rare-earth magnet motor having 1.2 times greater magnetic force (Same as the Model
WH 12DM2)
The Model WH 9DM2 is equipped with a new rare-earth magnet motor that is smaller than the Model WH 9DM
by 30% while providing higher power.
Equipped with a reinforced plastic gear for the decelerating unit
The gear is made of heat-resistant nylon resin reinforced with fiberglass.
It is lightweight and strong. In addition, the gear is uniquely shaped so
that the gear itself has the cushioning function. The Model WH 9DM2 is
lightweight thanks to deletion of the damper (a cushioning part) that is
used in the Model WH 12DM2. Cushioning
function
Product Unit
mm
Overall length mm
Weight g
Thickness
Hitachi
WH 9DM2
12 (15/32")
79 (7/64")
92 (0.2 lbs.)
Hitachi
WH 9DM
17 (43/64")
86 (25/64")
111 (0.25 lbs.)
C
12.5 (1/2")
74 (29/32")
75 (0.17 lbs.)

--- 5 ---
Product Unit
Overall length mm
Weight g
Hitachi
WH 9DM2
48.6 (1-29/32")
160 (0.35 lbs.)
Hitachi
WH 9DM
57.6 (2-17/64")
214 (0.47 lbs.)
C
57.0 (2-15/64")
175 (0.39 lbs.)
WH 9DM2 WH 9DM C
Product Unit
mm
Center height mm
Height mm
Overall length
Measured value kg
kgCatalog value
Weight
Hitachi
WH 9DM2
147 (5-25/32")
26.5 (1-3/64")
223 (8-25/32")
1.2 (2.6 lbs)
1.29 (2.8 lbs)
Hitachi
WH 9DM
167 (6-37/64")
26 (1-1/64")
221 (8-45/64")
1.4 (3 lbs)
1.46 (3.2 lbs)
164 (6-29/64")
25 (1-63/64")
236 (9-5/16")
1.1 (2.4 lbs)
1.13 (2.5 lbs)
C
Model
WH 9DM
C
Number of trigger switch depressing
0.68 N•m {6.9 kgf•cm, 6.0 in-lbs.}
2.0 times
(Reference) WH 12DM2
WH 9DM2 8.6 times
5.0 times
7.4 times
0.95 N•m {9.7 kgf•cm, 8.4 in-lbs.}
0.71 N•m {7.2 kgf•cm, 6.2 in-lbs.}
1.26 N•m {12.8 kgf•cm, 11.1 in-lbs.}
Table 1
3
(2) 30% lower striking start torque
The Model WH 9DM2 has lower striking start torque 0.68 Nm {6.9 kgf•cm, 6.0 in-lbs} than the current Model
WH 9DM (0.95 Nm {9.7 kgf•cm, 8.4 in-lbs}) to minimize damage to the screws. Thanks to the lower striking
start torque, the Model WH 9DM2 is optimum for light-duty works such as tightening sash screws, plastic
screws and Teks screws because it gives less damage to the small screws and the workpieces.
Table 1 shows a comparison of number of trigger switch operations when tightening a tapping screw D4 x 25
in a workpiece of nylon resin (prepared hole diameter 3.5 mm) until each driver idles. The Model WH 9DM2
has the highest resistance to idling because the number of adjustments is most frequent. (The switch is
turned off immediately after striking is started. The higher the striking start torque, the longer tightening time is
required and the driver is apt to idle.)
Compact and lightweight hammer assembly
The hammer assembly is newly designed according to the maximum tightening torque 80 N•m.
Comparison of the hammer assembly
4
Appearance and dimensions
Cordless impact driver: Model WH 9DM2
Striking start torque
* The data above are intended for reference purpose only because actual number of trigger
switch depressing may vary depending on tightening conditions.

--- 6 ---
Model WR 9DM2
(1) Class-top tightening torque 120 N•m (1220 kgf•cm, 1060 in-lbs.)
The right graph shows a comparison of tightening torque when
tightening an M12 high-strength bolt with a hexagonal socket
(overall length 33 mm) for 3 seconds. The Model WR 9DM2
provides the class-top tightening torque that is 40% higher than
the current Model WR 9DM and 30% higher than C.
Product Unit
mm
Center height mm
Height mm
Overall length
Measured value kg
kgCatalog value
Weight
Hitachi
WR 9DM2
160 (6-19/64")
26.5 (1-3/64")
223 (8-25/32")
1.4 (3 lbs.)
1.43 (3.1 lbs.)
Hitachi
WR 9DM
167 (6-37/64")
26 (1-1/64")
221 (8-45/64")
1.4 (3 lbs.)
1.46 (3.2 lbs.)
168 (6-39/64")
26 (1-1/64")
231 (9-3/32")
1.4 (3 lbs.)
1.49 (3.3 lbs.)
C
122
88 93
160
140
120
100
80
60
40
20
0
WR 9DM2 WR 9DM C
Tightening torque
(N.m)
(2) Compact
The overall length of the Model WR 9DM2 is 7 mm shorter than the current Model WR 9DM and 8 mm shorter
than C. It is convenient for work in narrow places.
Cordless impact wrench: Model WR 9DM2

--- 7 ---
5. SPECIFICATIONS
5-1. Specifications
Model Cordless impact driver
WH 9DM2
Capacity
Item
Cordless impact wrench
WR 9DM2
Small screw M4 --- M8 (5/32" --- 5/16")*1
Ordinary bolt M5 --- M12 (3/16" --- 15/32")
Ordinary bolt M6 --- M14 (1/4" --- 9/16")
High-strength bolt M6 --- M10 (1/4" --- 3/8")
Tightening torque 80 N•m (820 kgf •cm, 710 in-lbs.)*2120 N•m (1220 kgf •cm, 1060 in-lbs.)*3
Tip condition 6.35 mm (1/4") Bit holder 9.5 mm (3/8") Square drive
Type of motor Fan cooled DC magnet motor
Enclosure Main body: Polyamide resin •••••• Housing
Aluminum alloy die casting •••••• Hammer case
Storage battery: ABS resin (black)
Charger: ABS resin (black)
Type of switch
Trigger switch with forward/reverse changeover pushing button (with brake and variable)
Handle configuration T-type
No-load rotational speed 0 --- 2,800 /min
Impact rate 0 --- 3,200 /min
Main body 1.2 kg (2.6 lbs.)
Battery 0.55 kg (1.2 lbs.)
Overall length x height 147 mm (5-25/32") x 223 mm (8-25/32")
Center height 26.5 mm (1-3/64")
Battery (Type EB 9B) Sealed cylindrical nickel-cadmium batteries
Nominal voltage: DC 9.6V
Nominal life: Charging/discharging approximately 1,000 cycles (in the case of Model
UC 14YF2, UC 14YFA)
Nominal capacity: 2.0 Ah
160 mm (6-37/64") x 223 mm (8-25/32")
Battery (Type EB 930H) Sealed cylindrical nickel-metal hydride batteries
Nominal voltage: DC 9.6V
Nominal life: Charging/discharging approximately 500 cycles (in the case of Model
UC 14YF2, UC 14YFA)
Nominal capacity: 3.0 Ah
Charger (UC 14YF2) Charger power source: single-phase AC, 50/60 Hz
Voltage: Depending on the order specification
Power input: 44 W
Charging system: Constant current charge with full wave phase control
Overcharge protection system: (1) Battery voltage detection ( 2V system)
(2) Battery surface temperature detection
(thermostat or thermistor)
(3) 120-minute timer
Output voltage: 7.2 V --- 14.4 V
Output current: 1.9 A
Charging time: Approx. 60 minutes (for B-type storage battery at 20 ˚C)
Approx. 90 minutes (for H-type storage battery at 20 ˚C)
Product weight: 1.3 kg
Operable ambient temperature range: 0 ˚C --- 40 ˚C
The maximum allowable temperature of the EB 9B type battery is 60 ˚C and the
EB 930H type battery is 45 ˚C.
Weight
0 --- 2,600 /min
1.4 kg (3.0 lbs.)