Hitachi WH 12DAF2 Manual

TECHNICAL DATA
AND
SERVICE MANUAL
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST Nos. WH 12DAF2: G836
WR 12DAF2: G837
August 2005
W
MODELS
WH 12DAF2
WR 12DAF2
Hitachi 
Power Tools
CORDLESS IMPACT DRIVER
WH 12DAF2
CORDLESS IMPACT WRENCH
WR 12DAF2
WH 12DAF2 WR 12DAF2

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
WH 12DAF2
Symbol Utilized Competitor
Company Name Model Name
WR 12DAF2
P1 DeWALT DW053
PDeWALT DW052

Page
CONTENTS
1. PRODUCT NAME ............................................................................................................................ 1
2. MARKETING OBJECTIVE .............................................................................................................. 1
3. APPLICATIONS ............................................................................................................................... 1
4. STANDARD EQUIPMENT ............................................................................................................... 1
5. SELLING POINTS ........................................................................................................................... 2
5-1. Selling Point Descriptions ................................................................................................................ 4
6. SPECIFICATIONS ........................................................................................................................... 6
6-1. Specifications ....................................................................................................................................6
6-2. Optional Accessories ........................................................................................................................7
7. COMPARISONS WITH SIMILAR PRODUCTS .............................................................................. 11
7-1. Specification Comparisons ............................................................................................................. 11
7-2. Tightening Torque ...........................................................................................................................13
7-3. Number of Screws or Bolts Driven ..................................................................................................15
8. PRECAUTIONS IN SALES PROMOTION .................................................................................... 16
8-1. Safety Instructions ..........................................................................................................................16
8-2. Tightening Torque Inspection Prior to Operation ............................................................................18
8-3. Tightening Torque Variation ............................................................................................................18
8-4. Suggestions and Precautions for the Efficient Use of the Charger ................................................. 20
9. OTHER PRECAUTIONS ............................................................................................................... 20
10. REPAIR GUIDE ........................................................................................................................... 21
10-1. Precautions in Disassembly and Reassembly ..............................................................................21
10-2. Precautions in Disassembly and Reassembly of Battery Charger ............................................... 27
11. STANDARD REPAIR TIME (UNIT) SCHEDULES....................................................................... 28
For Model WH 12DAF2 ..........................................................................................................................28
For Model WR 12DAF2 ..........................................................................................................................29
Assembly Diagram for WH 12DAF2
Assembly Diagram for WR 12DAF2

--- 1 ---
1. PRODUCT NAME
Hitachi Cordless Impact Driver, Model WH 12DAF2
Hitachi Cordless Impact Wrench, Model WR 12DAF2
2. MARKETING OBJECTIVE
The new Models WH 12DAF2 and WR 12DAF2 are the upgraded versions of the well-reputed Models WH 12DAF
and WR 12DAF. They incorporate many features including the following with the comparable price.
Increased maximum tightening torque
Increased battery capacity (standard accessory)
Convenient belt hook with LED job light
Bit holder
Powerful new design
With the introduction of the new Models WH 12DAF2 and WR 12DAF2, we aim to increase our market share and
sales.
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
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 aids, automobile repair, assembly of garages
and carports storage sheds, etc.
Various other assembly, construction or repair facilities
4. STANDARD EQUIPMENT
(1) NN specification: Without battery, charger and case (only main body)
(2) 2SGK specification: Two EB 1214S batteries (NiCd, capacity 1.4 Ah), UC 18YG charger and case
(3) SGK specification: One EB 1214S battery (NiCd, capacity 1.4 Ah), UC 18YG charger and case
(4) 2SGKX specification: Two EB 1214S batteries (NiCd, capacity 1.4 Ah), UC 18YG charger, case and UB 12D
torchlight
(5) 2BLGK specification: Two EB 1220BL batteries (NiCd, capacity 2.0 Ah), UC 18YG charger and case
(6) 2HLFK specification: Two EB 1226HL batteries (NiMH, capacity 2.6 Ah), UC 14YFA charger and case
4

--- 2 ---
5. SELLING POINTS
(1) Cordless impact driver Model WH 12DAF2
Soft-grip handle
Variable speed reversible
switch with electric brake
Durable die-casting aluminum hammer case
Powerful new design
Convenient belt hook
with LED job light
Bit holder
Fast tightening speed
30% faster than the Model WH 12DAF
Max. torque 110 N•m (975 in-lbs.)
WH 12DAF: 88 N•m (780 in-lbs.)

--- 3 ---
(2) Cordless impact wrench Model WR 12DAF2
Soft-grip handle
Variable speed reversible
switch with electric brake
Durable die-casting aluminum hammer case
Powerful new design
Convenient belt hook
with LED job light
Max. torque 130 N•m (1150 in-lbs.)
WR 12DAF: 110 N•m (975 in-lbs.)

--- 4 ---
5-1. Selling Point Descriptions
Common selling points (Models WH 12DAF2 and WR 12DAF2)
(1) Soft-grip handle
The grip is soft, slip-resistant and comfortable thanks to the soft resin (elastomer) covered on the handle.
(2) Convenient belt hook with LED job light
It can be used as a hook for suspending from a waist belt or storing. Its yellow LED light is very convenient for
such operations as tightening screws in a dark place. This hook features the following:
It can be slid out when necessary and slid in when not necessary with one-touch simple operation. The
angle can be adjusted in 5 steps.
It can be installed on either right or left side. It is easily replaceable with a flat-blade screwdriver or a coin.
The yellow LED light can be lit by turning on its switch when necessary. The lighting direction is diagonal to
minimize shadowing over the tool tip and the operator's hand holding a screw. The light will turn off
automatically after 15 minutes if forgotten.
Selling points of the Model WH 12DAF2
(1) Fast tightening speed thanks to the powerful tightening torque (30% faster than the conventional model when
tightening a universal machine screw of 5.3 mm diameter and 120 mm length)
The maximum tightening torque and the tightening speed of the Model WH 12DAF2 are greatly increased in
comparison with the Model WH 12DAF thanks to the increased output of the motor and the large hammer.
Tightening time comparison
Figure 1 shows the time required for tightening a wood screw (5.3 mm dia. x 120 mm length) into a lauan
workpiece.
1
* Tightening time may vary depending on hardness of the workpiece, ambient temperature, characteristics
of the battery, etc.
Fig. 1 Tightening time comparison
WH 12DAF2
WH 12DAF
4.8 sec.
Model (sec.)
6.5 sec.
4.7 sec.
612
814
4
210
Fast Slow
P
16

--- 5 ---
Fig. 3
Selling points of the Model WR 12DAF2
(1) Max. torque 130 N•m (1150 in-lbs.)
The maximum torque is 130 N•m (1150 in-lbs.) thanks to the optimum striking design while maintaining high
mechanical strength with the durable die-casting aluminum hammer case etc.
(2) Tightening torque comparison
Figure 3 shows the torque required for tightening an M12 high-strength bolt in 3 seconds with a hexagon
socket (overall length 33 mm) (20 % higher than the Model WR 12DAF).
*1: Max. tightening torque is based on tighting an M16 F10T bolt in 3 seconds with a hexagon socket
(40 mm long).
* The data above are intended for reference purposes only because actual tightening torque will vary
depending on tightening conditions.
Tightening torque
0
80
60
40
20
100
120
140
WR 12DAF P1*1
kgf cm
113
164
134
WR 12DAF2
160
180
200
0
1800 (1562 in-lbs.)
2000 (1736 in-lbs.)
N
m
400 (347 in-lbs.)
800 (694 in-lbs.)
1200 (1042 in-lbs.)
1600 (1389 in-lbs.)
200 (174 in-lbs.)
1000 (868 in-lbs.)
600 (521 in-lbs.)
1400 (1215 in-lbs.)
(2) Max. torque 110 N•m (975 in-lbs.)
The maximum torque is 110 N•m (975 in-lbs.) thanks to the optimum striking design while maintaining high
mechanical strength with the durable die-casting aluminum hammer case, etc.
Tightening torque comparison
Figure 2 shows the torque required for
tightening an M12 high-strength tension
bolt in 3 seconds with a hexagon socket
(overall length 33 mm) (25% higher than
the Model WH 12DAF).
Fig. 2 Tightening torque comparison
113
40
80
160
0
WH 12DAF
WH 12DAF2
400 (347 in-lbs.)
800 (694 in-lbs.)
1200 (1042 in-lbs.)
N m
120
1600 (1389 in-lbs.)
90
116
140
100
60
200 (174 in-lbs.)
1000 (868 in-lbs.)
600 (521 in-lbs.)
1400 (1215 in-lbs.)
kgf cm
20
P *1
Tightening torque
1
*1: Max. tightening torque is based on tighting an M14 high-strength tension bolt in 3 seconds with a
hexagon socket (40 mm long).
(3) Bit holder
A bit holder is provided at the handle portion. It is very convenient for holding a spare bit.

--- 6 ---
6. SPECIFICATIONS
6-1. Specifications
Capacity Small screw M4 --- M8 (5/32" --- 5/16")*1
Ordinary bolt M5 --- M12 (3/16" --- 15/32")
High-strength bolt M5 --- M10 (3/16" --- 25/64")
Tightening torque*2110 N•m (1120 kgf •cm, 975 in-lbs.)
Tip condition 6.35 mm (1/4") bit holder
Type of motor Fan cooled DC magnet motor
Enclosure Main body: Glassfiber reinforced polyamide resin (black)
and thermoplastic elastomer (green)
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)
Handle configuration T-type
No-load rotational speed 0 --- 2,500/min
Impact rate 0 --- 2,900/min
Main body 1.6 kg (3.5 lbs.) (with battery EB 1214S)
1.7 kg (3.7 lbs.) (with battery EB 1220BL/EB 1226HL)
Battery 0.5 kg (1.1 lbs.) (EB 1214S)
0.6 kg (1.3 lbs.) (EB 1220BL/EB 1226HL)
Overall length x height 181 mm (7-1/8") x 217 mm (8-35/64")
(with battery EB 1214S)
182 mm (7-11/64") x 226 mm (8-29/32")
(with battery EB 1220BL/EB 1226HL)
Center height 26.5 mm (1-3/64")
Battery
(Type EB 1214S/
EB 1220BL)
Sealed cylindrical nickel-cadmium battery
Nominal voltage •••••••• DC 12 V
Nominal life •••••••••••••• Charging/discharging: approximately 300 cycles
(in the case of the Model UC 14YFA or UC 18YG)
Nominal capacity ••••••• 1.4 Ah/2.0 Ah
Weight
•••••• Housing
Battery
(Type EB 1226HL)
Sealed cylindrical nickel-metal hydride batteries
Nominal voltage •••••••• DC 12 V
Nominal life •••••••••••••• Charging/discharging: approximately 500 cycles
(in the case of the Model UC 14YFA)
Nominal capacity ••••••• 2.6 Ah
Item Model Cordless Impact Driver
WH 12DAF2
Cordless Impact Wrench
WR 12DAF2
Ordinary bolt M6 --- M14 (1/4" --- 9/16")
High-strength bolt M6 --- M10 (1/4" --- 25/64")
130 N•m (1330 kgf •cm, 1150 in-lbs.)
12.7 mm (1/2") square drive
176 mm (6-15/16") x 217 mm (8-35/64")
(with battery EB 1214S)
176 mm (6-15/16") x 226 mm (8-29/32")
(with battery EB 1220BL/EB 1226HL)
Charger power source: Single-phase AC, 50/60 Hz
Voltage: Depending on the order specification
Power input: 56 W
Charging system: Constant current charge with feedback control
Overcharge protection system: (1) Battery voltage detection ( 2V system)
Battery temperature detection (dT/dt system)
for Ni-MH battery
(2) Battery surface temperature detection
(thermistor)
(3) 120-minute timer
Output voltage: 7.2 V --- 14.4 V
Output current: 2.6 A
Charger
(Model UC 14YFA)

--- 7 ---
*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.
Charging time: Approx. 30 minutes (for type EB 1214S battery at 20ûC)
Approx. 60 minutes (for type EB 1226HL battery at 20ûC)
Approx. 50 minutes (for type EB 1220BL battery at 20ûC)
Power weight: 0.6 kg
Operable ambient temperature range: 0ûC --- 40ûC
The maximum allowable temperature of the EB 1214S or EB 1220BL type battery is
55ûC and the EB 1226HL type battery is 45ûC.
Charger
(Model UC 14YFA)
Overcharge prevention circuit:
A thermostat monitors the surface temperature of the battery and, on detecting the
temperature rise which occurs on completion of charging, automatically turns off the
unit to prevent the battery from overcharge.
Output capacity: 70 W
Indication method: Pilot lamp indicator of battery charging
Function: On.............................................................................. During charging
Off ............................................................................. Charging completed
Charger
(Model UC 18YG)
NOTE: The Model UC 18YG
charger is exclusive to
NiCad batteries.
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 (Model UC 14YFA)
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.
6-2. Optional Accessories
(1) Battery (EB 1214S, EB 1220BL, EB 1226HL)
(2) For the Model WH 12DAF2
There are two types of attachment sizes for the driver bit and the socket. Please refer to the table below and
select the attachment size for the driver bit or socket that is appropriate for your WH 12DAF2.