Hitachi WH9DM Manual

POWER TOOLS
TECHNICAL DATA
AND
SERVICE MANUAL
CORDLESS IMPACT DRIVER
WH 9DM
CORDLESS IMPACT WRENCH
WR 9DM
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST Nos. WH 9DM: F863
WR 9DM: F865 Oct. 2001
W
MODEL
WH 9DM
WH 9DM WR 9DM
WR 9DM
2000mAh
WH9DM
2000mAh
WR9DM

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
C MAKITA 6990D
WH 9DM

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 ..........................................................................................................................6
5-1. Specifications................................................................................................................................. 6
5-2. Optional Accessories ..................................................................................................................... 7
6. COMPARISONS WITH SIMILAR PRODUCTS ............................................................................10
6-1. Specification Comparisons (Cordless Impact Driver) .................................................................. 10
6-2. Specification Comparisons (Cordless Impact Wrench) ................................................................11
6-3. Tightening Torque ........................................................................................................................ 12
6-4. Tightening Speed ......................................................................................................................... 15
6-5. Number of Screws or Bolts Driven............................................................................................... 16
7. PRECAUTIONS IN SALES PROMOTION ...................................................................................17
7-1. Safety Instructions ....................................................................................................................... 17
7-2. Tightening Torque Inspection Prior to Operation ......................................................................... 19
7-3. Tightening Torque Variation ......................................................................................................... 19
7-4. Suggestions and precautions for the Efficient Use of the Charger .............................................. 20
8. OTHER PRECAUTIONS ..............................................................................................................21
9. REPAIR GUIDE ............................................................................................................................22
9-1. Precautions in Disassembly and Reassembly............................................................................. 22
9-2. Precautions in Disassembly and Reassembly of Battery Charger .............................................. 29
10. STANDARD REPAIR TIME (UNIT) SCHEDULES .....................................................................30
Assembly Diagram for WH 9DM
Assembly Diagram for WR 9DM

--- 1 ---
1. PRODUCT NAME
Hitachi Cordless Impact Driver, Model WH 9DM
Hitachi Cordless Impact Wrench, Model WR 9DM
2. MARKETING OBJECTIVE
The new cordless impact driver Model WH 9DM and the new cordless impact wrench Model WR 9DM are
brought out as DC 9.6 V products of the Super Impact series. They are upgraded versions of the previous Models
WH 8DH and WR 8DH, developed under the concept for more compact, powerful and convenient models to
expand the market share of our cordless impact products.
The Model WH 9DM provides 30% faster tightening speed than the previous Model WH 8DH and this is the class-
top speed. The WR 9DM has a square drive dimension of 9.5 mm. Since the Model WR 12DM has a square
dimension of 12.7 mm, two square drive dimensions are available with those Impact series.
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 12DM
• Newly designed compact body
• Ergonomically designed comfortable
handle (slip-resistant double-molded
grip)
• Convenient hook
(with the torsion bit holder)
• Stable flat battery (interchangeable)
• High durability, dust resistance and
long service life
2000mAh
WH 9DM
4. SELLING POINTS
(1) Cordless Impact Driver: WH 9DM
Class-top tightening speed
30% faster than the previous model
(Example: When tightening a wood screw 90 mm in length)
WH 9DM: 3.8 seconds
WH 8DH: 5.2 seconds
C: 5.0 seconds
-Reference-
WH 12DM (new model): 2.9 seconds
WH 12DH (previous model): 4.1 seconds
Compact body
Overall length of the Model
WH 9DM compared with
following models:
WH 8DH: -9 mm
C: -1 mm
(Reference)
WH 12DM: 0 mm
Height of the Model WH 9DM
with respect to:
WH 8DH: +1 mm
C: -10 mm
(Reference)
WH 12DM: -5 mm Lightweight
Weight of the Model WH 9DM
compared with following models:
WH 8DH: -200 g
C: 0 g
(Reference)
WH 12DM: -200 g

--- 3 ---
2000mAh
WR 9DM
(2) Cordless Impact Wrench: WR 9DM
Selling points common to the
Model WH 12DM
•Newly designed compact body
•Ergonomically designed comfortable
handle (slip-resistant double-molded
grip)
•Convenient hook
•Stable flat battery (interchangeable)
•High durability, dust resistance and
long service life
Compact body
Overall length of the Model WR 9DM
compared with following models:
WR 8DH: -14 mm
(Reference)
WR 12DM: -6 mm
Height of the Model WR 9DM with
respect to:
WR 8DH: +1 mm
(Reference)
WR 12DM: -5 mm
Lightweight
Weight of the Model WR 9DM
compared with following
models:
WR 8DH: -200 g
WR 12DM: -200 g
9.5 mm (3/8")
(Reference) WR 12DM: 12.7 mm (1/2")

--- 4 ---
4-1. Selling Point Descriptions
Refer to pages 4 through 8 of Technical Data Service Manual for the Models WH 12DM/WR 12DM for common
selling points.
(1) Compact body (WH 9DM/WR 9DM)
The Models WH 9DM/WR 9DM are equipped with a separate-type motor in which the armature is separated
from the magnet like a 100-V motor while the previous models are equipped with an integrated-type motor
contained in a steel case. Thanks to the new separate-type motor, the steel case is eliminated and the motor
section is downsized. In addition, the hammer case is downsized. The overall length of the Models WH 9DM/
WR 9DM is shortened by 8 mm and the girth is shortened by 10 mm in comparison with the previous models
WH 8DH/WR 8DH. The Models WH 9DM/WR 9DM are convenient for working in narrow places. The weight
is about 70 g lighter than the Model WH 12DM (12-V product). The reason why the Models WH 9DM/
WR 9DM are heavier than C by 80 g is because they are equipped with a metal ring gear while C is equipped
with a plastic ring gear. In performance, however, the Model WH 9DM provides 30% faster tightening speed
than C and this is the class-top speed.
2000mAh
WH9DM
H
L
A
Model Unit
mm
A Center height mm
H Height mm
L Overall length
Actual weight kg
kgCatalog weight
Weight
WH 9DM
167 (6-37/64")
26 (1-1/64")
221 (8.7")
1.4 (3.0 lbs)
1.49 (3.3 lbs)
WH 8DH
176 (6-15/16")
26 (1-1/64")
220 (8-21/32")
1.6 (3.5 lbs)
1.60 (3.5 lbs)
6990D
168 (6-39/64")
26 (1-1/64")
231 (9-3/32")
1.4 (3.0 lbs)
1.41 (3.1 lbs)
WH 12DM
(12-V product)
167 (6-37/64")
26 (1-1/64")
226 (8.9")
1.6 (3.5 lbs.)
1.66 (3.7 lbs.)
Cordless impact driver: WH 9DM
Cordless impact driver: WR 9DM
Model Unit
mm
A Center height mm
H Height mm
L Overall length
Actual weight kg
kgCatalog weight
Weight
WR 9DM
167 (6-37/64")
26 (1-1/64")
221 (8.7")
1.4 (3.0 lbs)
1.49 (3.3 lbs)
WR 8DH
181
26 (1-1/64")
220 (8-21/32")
1.6 (3.5 lbs)
1.60 (3.5 lbs)
173 (6-13/16")
26 (1-1/64")
226 (8.9")
1.6 (3.5 lbs)
1.67 (3.7 lbs)
WH 12DM
(12-V product)

--- 5 ---
(2) Class-top tightening speed (WH 9DM)
The Model WH 9DM is equipped with the new rare-earth magnet motor that is more powerful than the
previous model by 30%. Thanks to the new motor and the computer analysis, the Model WH 9DM gives
optimum impact at tightening screws and the tightening speed is 30% higher than the previous model and is
the class-top speed (also 30% higher than C). Tightening time comparison of the Model WH 9DM with the
previous Model WH 8DH and C is shown below (refer to pages 15 and later for detailed data on the tightening
time and the working capacity). For reference, the tightening speed of the Model WH 9DM is about 8% higher
than the previous Model WH 12DH (12 V product) though it is about 40% slower than the Model WH 12DM.
HITACHI WH 9DM
HITACHI WH 8DH
C
3.8 sec.
Model 510 sec.
5.2 sec.
5.0 sec.
Reference (12-V product):
2.4 sec.
4.1 sec.
67894321
WH 12DH
Fast Slow
WH 12DM
Tightening time comparison (Wood screw: 4.5 mm dia. x 90 mm length, hemlock spruce)
* Tightening time may vary depending on hardness of the workpiece, ambient temperature, characteristics
of the battery, etc.

--- 6 ---
5. SPECIFICATIONS
5-1. Specifications
Model Cordless Impact Driver
WH 9DM
Capacity
Item Cordless Impact Wrench
WR 9DM
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 95 N•m (970 kgf•cm, 840 in-lbs.)*2
88.2 N•m (900 kgf•cm, 780 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 --- 2,300 /min
Impact rate 0 --- 3,000 /min
Main body 1.4 kg (3.0 lbs.) (Includes battery)*4
Battery 0.55 kg (1.2 lbs.)
Overall length x height 167 mm (6-37/64") x 221 mm (8.7")
Center height 26 mm (1-1/64")
Battery (Type EB 9B) Sealed cylindrical nickel-cadmium batteries
Nominal voltage: DC 9.6V
Nominal life: Charging/discharging approximately 1,000 cycles (in case of Model
UC 14YF2)
Nominal capacity: 2.0 Ah
167 mm (6-37/64") x 221 mm (8.7")
Battery (Type EB 930H) Sealed cylindrical nickel-metal hydride batteries
Nominal voltage: DC 9.6V
Nominal life: Charging/discharging approximately 500 cycles (in case of Model
UC 14YF2)
Nominal capacity: 3.0 Ah
*1: In the case of tapping screws and wood screws, a minimum of M3 (1/8") is possible.
*2: This torque is based on tightening an M12 (15/32") bolt (strength grade: 12.9) for 3 seconds with a hexagonal socket.
*3: This torque is based on tightening an M12 (15/32") bolt (strength grade: 12.9) for 3 seconds with a hexagonal socket.
*4: Main body does not include accessory tools (hexagonal bit, etc.).
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

--- 7 ---
Prior to charging
During charging
Charging completed
Charging not
possible
High battery
temperature
Blinks
Lit
Blinks
Flickers
Lit
0.5 sec ON, 0.5 sec OFF
Stays ON constantly
0.5 sec ON, 0.5 sec OFF
0.1 sec ON, 0.1 sec OFF
Stays ON constantly
Pilot lamp indications (UC 14YF2)
Red pilot lamp
remains lit or flashes.
Green pilot lamp is lit.
Storage battery or charger
is faulty.
Charging not possible
because storage battery
temperature is too high.
5-2. Optional Accessories
(1) Optional accessories for the Model WH 9DM
•Plus driver bit
50 mm (2")
Bit No.
No. 2
No. 3
Code No.
992671
992672
•Hexagon socket
L
B
Stamped figures
9961778 (5/16")65 (2-9/16")8
Stamped figures
5 mm Hexagon socket
Part name L
(mm) B (mm) Code No.
98532910 (3/8")65 (2-9/16")106 mm Hexagon socket
99617812 (15/32")65 (2-9/16")125/16" Hexagon socket 99617913 (1/2")65 (2-9/16")138 mm Hexagon socket
99618014 (9/16")65 (2-9/16")1410 mm Hexagon socket (small type)
99618116 (5/8")65 (2-9/16")1610 mm Hexagon socket 99618217 (21/32")65 (2-9/16")1710 mm Hexagon socket
99619721 (53/64")166 (6-17/32")211/2" Hexagon long socket
•Woodworking drill bit (Code No. 959183)
14 mm dia.
(35/64")
83 mm (3-17/64")