Hitachi G 10SF3 Manual

POWER TOOLS
TECHNICAL DATA
AND
SERVICE MANUAL
DISC GRINDER
G 10SF3
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No. E243 Aug. 2001
G
MODEL
G 10SF3

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:
Symbols Utilized
Competitors
Company Name Model Name
MAKITA 9523NB
C

Page
CONTENTS
1. PRODUCT NAME ...........................................................................................................................1
2. MARKETING OBJECTIVE .............................................................................................................1
3. APPLICATIONS ..............................................................................................................................1
4. SELLING POINTS ..........................................................................................................................1
5. SPECIFICATIONS ..........................................................................................................................3
6. COMPARISONS WITH SIMILAR PRODUCTS ..............................................................................4
6-1. Specification Comparisons ............................................................................................................ 4
6-2. Comparisons in Torque vs. Rotation Speed and Stator Coil Temperature Rise ............................ 5
7. PRECAUTIONS IN SALES PROMOTION .....................................................................................6
7-1. Handling Instructions ..................................................................................................................... 6
7-2. Caution Plate (For China only) ...................................................................................................... 6
7-3. Precautions on Usage ................................................................................................................... 6
8. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY ............................................................7
8-1. Disassembly .................................................................................................................................. 7
8-2. Reassembly ................................................................................................................................... 9
8-3. Lubrication Points and Types of Lubricant .................................................................................... 11
8-4. Tightening Torque ......................................................................................................................... 11
8-5. Wiring Diagram ............................................................................................................................. 11
8-6. Insulation Tests ............................................................................................................................ 12
8-7. No-load Current Value ................................................................................................................. 12
9. STANDARD REPAIR TIME (UNIT) SCHEDULES .......................................................................13
Assembly Diagram for G 10SF3

--- 1 ---
1. PRODUCT NAME
Hitachi Disc Grinder, Model G 10SF3 [100 mm (4")]
2. MARKETING OBJECTIVE
The current Model G 10SF2 has been favorably accepted in the compact disc grinder market in China. However,
recent Chinese market is fiercely competitive due to a price war. To address the severe situation, we have
developed a new disc grinder Model G 10SF3 that is comprised of parts manufactured in China. The Model
G 10SF3 is more powerful than the current Model G 10SF2 thanks to the improved cooling efficiency of the motor.
The components of the Model G 10SF3 are the same as those of the Model G 10SF2 except the enclosure and
the wiring components.
3. APPLICATIONS
Removal of casting fin and finishing of various types of steel, bronze, aluminum, and other metallic materials
and castings
Grinding of welded sections, or sections cut by acetylene torch
Grinding of slate, brick, marble and similar materials
4. SELLING POINTS
High power input: 560 W
(G 10SF2 and C: 540 W)
New vaned dust seal efficiently
prevents dust from entering the ball
bearing on the commutator side.
Easy-to-use snap switch
Excellent wear resistance of armature coil:
2 times higher than the Model G 10SF2
1.7 times higher than C

--- 2 ---
Excellent wear resistance of armature coil
Wear resistance of the armature coil is greatly increased thanks to the smaller air vent to minimize sucking
dust and fine gravel into the machine.
G 10SF3
(Comparison of wear resistance of armature coils when dust and fine gravel are sucked into the machines)
(Comparison of air vents near the commutator)
Smaller air vent is
provided near the
commutator. Two air vents are provided
near the commutator.
G 10SF2
100
40
100
G10SF3
G10SF2
50
C
10 13.5
0
60

--- 3 ---
Depressed
center
wheel
5. SPECIFICATIONS
4,300 m/min (14,100 ft/min, 72 m/s)
Dimensions
Model
Item
O.D. 100 mm (4") x Thickness 4 mm (5/32")
x I.D. 16 mm (5/8")
Offset amount: 4 mm (5/32")
Max. peripheral speed
G 10SF3
AC single phase 50 or 60 Hz
Power source
Snap switch
1.4 kg (3.09 lbs.)
2.4 kg (5.3 lbs.)
Corrugated cardboard box
No-load speed
Type of motor
Enclosure
Type of switch
Weight Net: *1
Gross:
Packaging
Standard accessories*2Depressed center wheel [Outer dia.100 mm (4") ] .................1
Wrench ...................................................................................1
Voltage, current and power input
12,000/min
AC single phase commutator motor
Housing tail cover
Gear cover
Inner cover packing gland
Glassfiber reinforced polycarbonate resin (Green)
Aluminum alloy die casting (Metallic silver)
Aluminum alloy die casting
Voltage (V)
Current (A)
Power input (W)
220
560
2.7
*1: Net weight excludes cord, depressed center wheel, wheel nut, wheel washer and wheel guard.
*2: Standard accessories are subject to change without prior notice.

--- 4 ---
HITACHI
G 10SF3
100
12,000
560
380
640
254
67
60
200
1.4
(1.5)
Snap
Maker
Model
Wheel diameter mm
No-load speed /min
Power input W
Power output W
Max. power output W
L mm
Dimensions W mm
H mm
P mm
Weight * kg
(Actual weight)
Type of switch
6. COMPARISONS WITH SIMILAR PRODUCTS
6-1. Specification Comparisons
G 10SF2
100
12,000
540
330
610
254
67
60
200
1.4
(1.5)
Snap
100
11,000
540
290
620
256
81
70
195
1.4
(1.5)
Slide
C
L
H
W
P: Perimeter
* Weight excludes cord, depressed center wheel, wheel nut, wheel washer and wheel guard.

--- 5 ---
6-2. Comparisons in Torque vs. Rotation Speed and Stator Coil Temperature Rise
Figure 1 shows comparisons of the rotation speed and the stator coil temperature rise between a competitive
model with respect to torque. Torque represents the magnitude of load, i.e., the amount of pressing force, cutting
depth and forward force in actual cutting jobs. This shows that a powerful motor is less likely to burn out because
it has both a minimum drop of rotation speed even at a greater torque and a lower stator coil temperature rise at
the same torque.
Fig. 1 Comparisons in torque vs. rotation speed and stator coil temperature rise
Figure 1 indicates the followings:
The motor speed of the Model G 10SF3 is higher than that of C at the same torque. This means that the
working efficiency of the Model G 10SF3 is superior to C (Model G 10SF2 is also superior to C).
The stator coil temperature rise of the Model G 10SF3 is lower than the Model G 10SF2 thanks to the
improved cooling mechanism and it is equivalent to that of C. This means that the Model G 10SF3 has a burn-
resistant and tenacious motor.
Load
Stator coil temp. rise (K)
2,000
0
C
4,000
6,000
8,000
12,000
10,000
0
0
600
100
200
300
400
500
Rotation speed of spindle (/min.)
X
X
X
C
Torque range
HITACHI G 10SF3
Stator coil temp. rise
X: Burn-out point
HITACHI G10SF2
HITACHI G 10SF2, G 10SF3
Rotation speed of spindle

--- 6 ---
7. PRECAUTIONS IN SALES PROMOTION
In the interest of promoting the safest and most efficient use of the Model G 10SF3 Disc Grinder by all of our
customers, it is very important that at the time of sale, the salesperson carefully ensures that the buyer seriously
recognizes the importance of the contents of the Handling Instructions, and fully understands the meaning of the
precautions listed on the Name Plate attached to each tool.
7-1. Handling Instructions
Although every effort is made in each step of design, manufacture and inspection to provide protection against
any hazards, the dangers inherent in the use of any electric tool cannot be completely eliminated. Accordingly,
general precautions and suggestions for the use of electric power tools, and specific precautions and suggestions
for the use of the disc grinders are listed in the Handling Instructions to enhance the safe, efficient use of the tool
by the customer. Salespersons must be thoroughly familiar with the contents of the Handling Instructions to be
able to offer appropriate guidance to the customer during sales promotion.
7-2. Caution Plate (For China only)
The following caution is listed on the Name Plate attached to the main body of each tool.
7-3. Precautions on Usage
Instruct the customer to pay particular attention to the two points described below.
(1) Use of the side handle (Optional accessory)
When the side handle is used, the customer must be instructed to ensure without fail that the wheel guard is
mounted in the manner so that it protects the operator's hand from coming into contact with the depressed
center wheel.
Fig.2
Side handle
Pushing button
Wheel guard
(2) Never press the pushing button while the depressed center wheel is rotating.
If the pushing button (Fig. 2) is pressed while the depressed center wheel is rotating, the spindle will stop
immediately. In such a case, there is a danger that the wheel nut may be loosened, so that the depressed
center wheel flies out unexpectedly and may cause possibly serious injury.

--- 7 ---
8. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY
Procedures and precautions for disassembly and reassembly are described below. The [Bold] numbers in the
descriptions below correspond to the item numbers in the Parts List and the exploded assembly diagram.
8-1. Disassembly
(1) Disassembly of the armature
Remove the Brush Caps [39], and take out the Carbon Brushes [40].
Loosen the four Tapping Screws D5 x 25 [1] which fix the Gear Cover Ass'y [3], and remove the Inner
Cover [8] together with the Armature 220 V [9] from the Housing [34].
(2) Disassembly of the pinion
Loosen the Special Nut M7 [4] on the Armature 220 V [9], and remove the Pinion [5].
(3) Disassembly of the stator
Remove the Armature 220 V [9] and loosen the Tapping Screw (W/Flange) D4 x 25 (Black) [48] to remove
Tail Cover (B) [47].
Loosen the Machine Screw (W/Washer) M3.5 x 6 [49] that secures the internal wire of the Cord [51] to the
Switch [50] and also the screw on the cord side of the Pillar Terminal [43]. Remove the two internal wires
from the Cord [51].
Remove the Tapping Screw (W/Flange) D4 x 40 [38] and the Tapping Screw (W/Flange) D4 x 20 (Black)
[37]. Remove Tail Cover (A) [36] then remove the Earth Terminal [44] from the Housing [34].
Disconnect the two Internal Wires [13] coming from the Brush Holder [41] from the Stator [11].
Remove the Internal Wires [12] and [14] from the Stator [11] with the Pillar Terminal [43], Noise Suppressor
[46] and Switch [50] connected.
Loosen the Hex. Hd. Tapping Screw D4 x 65 [10] securing the Stator [11]. Remove the Stator [11] from the
Housing [34].

--- 8 ---
(4) Disassembly of the gear (Fig. 3)
Loosen the Seal Lock Screw (W/Sp. Washer) M4 x 12 [23] fixing the Packing Gland [22], and remove the
Packing Gland [22] from the Gear Cover Ass'y [3].
Support the button of the Packing Gland [22] with a jig, and push down on the upper portion of the Spindle
M10 x P1.5 [25] with a hand press until the end surface of the Woodruff Key 2.5 x 8 [24] contacts the Ball
Bearing 6001VVCMPS2L [20] and the Spindle M10 x P1.5 [25] cannot be pushed down any more. Be
careful not to deform the Fringer [26].
Turn the Packing Gland [22] upside down and fix it, then push down the Spindle M10 x P1.5 [25].
Insert the gear puller J-128 (use of a steel plate is permitted as a substitute) between the Gear [17]
and the Packing Gland [22], and push down the Spindle M10 x P1.5 [25] with a hand press to remove it.
[25]
[24]
[26]
Fig. 3
Replace the Ball Bearing 6001VVCMPS2L [20] with new one every time the Gear is disassembled
because the force to pull out the Gear is applied to the Ball Bearing 6001VVCMPS2L [20].
[20]
[25]
[20]
[22]
Push Push
Push
[24]
[22]
[20]
[25]
[22]
[17]
Step Step Step
Gear puller J-128
(steel plate)

--- 9 ---
8-2. Reassembly
Push the parts together in the reverse order of disassembly, with the precautions given below.
(1) Ensure that the terminals of the stator are not bent or otherwise damaged.
(2) Generously lubricate the teeth of Gear [17] and Pinion [5] with grease. Rub grease onto the teeth with your
fingers so that the grease reaches each tooth bottom. Note that the Gear [17] and the Pinion [5] may wear
faster than normal if under-lubricated.
(3) Be sure to soak the inner diameter of the Felt Packing [21] with machine oil. Otherwise, its dust-sealing
function will fail to work properly, resulting in earlier damage of the Ball Bearing 6001VVCMPS2L [20].
(4) When replacing the Armature 220 V [9] and the Ball Bearing 608VVC2PS2L [7] on the commutator side, press
inward on the Dust Seal [15] while taking care of its direction until the end face of the Dust Seal [15] contacts
against the end surface of the Armature 220 V [9] and make sure that Dust Seal [15] cannot be turned freely
by hand. Keep the end face of the armature shaft approximately 0.2 mm (reference) distance inward of the
end face of the Ball Bearing 608VVC2PS2L [7]. (See Fig. 5.)
The Dust Seal [15] is an important element for improved dust protection of the Ball Bearing 608VVC2PS2L
[7]. Be sure to replace with a new one each time.
Fig. 5
Armature shaft
About 0.2 mm (reference)
Ball Bearing 608VVC2PS2L [7]
Dust Seal [15]
(5) When connecting the Earth Terminal [44] to the internal wire (the middle wire among three) of the Noise
Suppressor [46], strip the insulation sheath on the internal wire by about 6 mm and press connect it together
with the Earth Terminal [44] with a clamping tool available on the market.
Fig. 6
Solderless connection
(6) Connect the Internal Wires [12], [13] and [14] to the Stator [11] correctly as shown in Fig. 7.
(7) Connect each internal wire correctly as shown in Fig. 8 being careful not to put them between the parts.

--- 10 ---
Fig. 7
Fig. 8
Fit the Internal Wire 85L [13] between
the housing ribs securely (4 pcs.).
Brush Holder [41]
Connect the terminal securely without folding.
Fit the internal wire of the Cord [51] between the ribs.
Fit each internal wire between the ribs.

--- 11 ---
(8) When replacing the Gear Cover Ass'y [3], lubricate the metal part with mixed oil.
Mixed oil: A mixture of Hitachi Power Tool Grease No. 2 (Unilube No. 00 Code No. 939302 is recommended)
and turbine oil
Mixture ratio ......... 1:1 (weight ratio) Quantity ........... 0.5 cc
8-3. Lubrication Points and Types of Lubricant
Pinion chamber of Gear Cover Ass'y [3] ..................... Nippeco grease (SEP-3A) 10 g
(Code No. 930035 is recommended.)
Generously rub grease onto the gear and pinion.
Metal ............................................................................ Mixed oil 0.5 cc
Mixed oil: Mixture of Hitachi Power Tool Grease No. 2
(Unilube No. 00, Code No. 939302) and
turbine oil
Mixture ratio ................1:1 (weight ratio)
8-4. Tightening Torque
D4 Tapping Screws [10] [37] [38] [48].................................... 2.0 0.5 N•m (20 5 kgf•cm, 1.5 0.4 fb-lbs.)
M4 Slotted Hd. Tapping Screw (Seal Lock) [6] ....................... 1.8 0.4 N•m (18 4 kgf•cm, 1.3 0.3 fb-lbs.)
M4 Seal Lock Screws (W/Sp. Washer) [18] [23] .................... 1.8 0.4 N•m (18 4 kgf•cm, 1.3 0.3 fb-lbs.)
D5 Tapping Screw [1].............................................................. 2.9 0.5 N•m (30 5 kgf•cm, 2.2 0.4 fb-lbs.)
M5 Machine Screw (W/Sp. Washer) [27]................................ 1.6 0.4 N•m (16 4 kgf•cm, 1.2 0.3 fb-lbs.)
M7 Special Nut [4] .................................................................. 6.4 1.0 N•m (65 10 kgf•cm, 4.7 0.7 fb-lbs.)
Brush Cap [39]........................................................................ 0.6 0.2 N•m (6 2 kgf•cm, 0.4 0.1 fb-lbs.)
8-5. Wiring Diagram
Black
Noise
Suppressor [46]
Pillar Terminal [43]
Cord [51]
Switch [50]
Stator [11]
Black Black
Black
Blue
Brown

--- 12 ---
8-6. Insulation Tests
On completion of disassembly and repair, carefully measure the insulation resistance and conduct a dielectric
strength test.
Insulation resistance: 7 M Ωor more with 500 V DC Megohm Tester
Dielectric strength test: AC 4,000 V/1 minute with no abnormalities
8-7. No-load Current Value
After no-load running for 30 minutes, the no-load current value should be as follows.
Voltage (V)
Current (A) max.
220
1.1

--- 13 ---
9. STANDARD REPAIR TIME (UNIT) SCHEDULES
MODEL 10 20 30 40
Fixed
Variable
Work Flow
Pushing Button
Gear Cover
Ass'y
Lock Pin
Gear
60 min.
50
Bearing Cover
(B)
Ball Bearing
6001VVCMPS2L
Felt Packing
Packing Gland
Spindle
Fringer
Wheel Guard
Ass'y
Switch
Cord
Tail Cover (A)
Tail Cover (B)
Pinion
Ball Bearing
608VVC2PS2L
x 2
Inner Cover
Armature
Dust Seal
General Assembly
G 10SF3
Housing
Stator

ELECTRIC TOOL PARTS LIST
LIST NO.
DISC GRINDER
Model G 10SF3
2001
•
8
•
10
(E1)
E243
1
2
3
4
5
6
7
8
10
11
12
9
13
13
14
15
7
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
34
35
36
37
38
40
41
42
43
44 45
46
47
48
49
50
51
501
33
39

*ALTERNATIVE PARTS
--- 2 ---
ITEM
NO. CODE NO. DESCRIPTION REMARKS
NO.
USED
PARTS G 10SF3
8-- 01
1 937-807 TAPPING SCREW D5X25 4
2 301-944 PUSHING BUTTON 1
3 303-078 GEAR COVER ASS’Y 1 INCLUD.2,16
4 301-941 SPECIAL NUT M7 1
5 301-939 PINION 1
6 301-936
SLOTTED HD. SCREW (SEAL LOCK) M4X10 2
7 608-VVM BALL BEARING 608VVC2PS2L 2
8 301-935 INNER COVER 1
9 360-464E ARMATURE 220V 1
10 963-712 HEX. HD. TAPPING SCREW D4X65 2
11 340-428E STATOR 220V 1
12 320-273 INTERNAL WIRE 70L 1
13 320-274 INTERNAL WIRE 85L 2
14 320-275 INTERNAL WIRE 60L 1
15 315-877 DUST SEAL 1
16 301-943 LOCK PIN 1
17 301-940 GEAR 1
18 997-263
SEAL LOCK SCREW (W/SP. WASHER) M4X10 3
19 938-058 BEARING COVER (B) 1
20 600-1VV BALL BEARING 6001VVCMPS2L 1
21 301-946 FELT PACKING 1
22 301-947 PACKING GLAND 1
23 307-127
SEAL LOCK SCREW (W/SP. WASHER) M4X12 4
24 940-220 WOODRUFF KEY 2.5X8 1
25 302-046 SPINDLE M10XP1.5 1
26 301-945 FRINGER 1
27 308-386 MACHINE SCREW (W/SP. WASHER) M5X16(BLACK) 2
28 301-949 SET PLATE 1
29 301-948 WHEEL GUARD ASS’Y 1 INCLUD.27,28
30 310-787 WHEEL WASHER 1
31 316-820 D. C. WHEELS 100MMX4T A36Q (25 PCS.) 1
32 314-437 WHEEL NUT (C) 1
33 301-938 GEAR AND PINION ASS’Y 1 INCLUD.5,17
34 320-271 HOUSING 1
35 NAME PLATE 1
36 320-276 TAIL COVER (A) 1
37 302-086
TAPPING SCREW (W/FLANGE) D4X20 (BLACK) 1
38 306-664 TAPPING SCREW (W/FLANGE) D4X40 1
39 936-551 BRUSH CAP 2
40 999-021 CARBON BRUSH (1 PAIR) 2
41 313-777 BRUSH HOLDER 2
42 980-063 TERMINAL 1 FOR CORD
43 938-307 PILLAR TERMINAL 1
44 314-854 EARTH TERMINAL 1
45 980-063 TERMINAL 1 FOR NOISE SUPPRESSOR
46 994-273 NOISE SUPPRESSOR 1
47 320-272 TAIL COVER (B) 1
48 304-035
TAPPING SCREW (W/FLANGE) D4X25 (BLACK) 1
49 305-499 MACHINE SCREW (W/WASHER) M3.5X6 2
50 955-509 SWITCH (1P SCREW TYPE) 1
* 51 315-879 CORD 1

*ALTERNATIVE PARTS --- 3 ---
ITEM
NO. CODE NO. DESCRIPTION REMARKS
NO.
USED
PARTS
* 51 500-237Z CORD 1 FOR HKG
G 10SF3
8-- 01

*ALTERNATIVE PARTS
--- 4 ---
ITEM
NO. CODE NO. DESCRIPTION REMARKS
NO.
USED
STANDARD ACCESSORIES G 10SF3
501 313-933 WRENCH 1
Printed in Japan
(010810N)
8 -- 01