Hitachi H 70SD Manual

POWER TOOLS
TECHNICAL DATA
AND
SERVICE MANUAL
HAMMER
H 70SD
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No. E461 Dec. 2001
H
MODEL
H 70SD

1. PRODUCT NAME ...........................................................................................................................1
2. MARKETING OBJECTIVE .............................................................................................................1
3. APPLICATIONS ..............................................................................................................................1
4. SELLING POINTS ..........................................................................................................................1
4-1. Selling Point Descriptions .............................................................................................................. 2
5. SPECIFICATIONS ..........................................................................................................................4
5-1. Optional Accessories ..................................................................................................................... 5
6. COMPARISONS WITH SIMILAR PRODUCTS ..............................................................................7
6-1. Specification Comparisons ............................................................................................................ 7
6-2. Demolition Performance Comparisons .......................................................................................... 8
7. PRECAUTIONS IN SALES PROMOTION .....................................................................................8
7-1. Handling Instructions ..................................................................................................................... 8
7-2. Caution Plate ................................................................................................................................. 8
7-3. Grease Replacement ..................................................................................................................... 9
7-4. O-Ring Replacement ..................................................................................................................... 9
8. REFERENCE INFORMATION ......................................................................................................10
8-1. Sealed and Dustproof Construction ............................................................................................. 10
8-2. Vibration-Absorbing Construction ................................................................................................ 10
8-3. Tool Retainer ................................................................................................................................ 13
9. REPAIR GUIDE ............................................................................................................................14
9-1. Precautions and Suggestions for Disassembly and Reassembly of the Main Body .................... 14
10. STANDARD REPAIR TIME (UNIT) SCHEDULES .....................................................................23
Assembly Diagram for H 70SD
CONTENTS
Page

--- 1 ---
1. PRODUCT NAME
Hitachi Electric Hammer, Model H 70SD
2. MARKETING OBJECTIVE
The Model H 70SD has been developed based on the current Model H 65SD, which features the use of 28.5 mm
(1-1/8") air tool shank tools, standard hexagonal shank tools (combo type), and retaining groove tools without
collar. While the Model H 65SD has a D-shaped handle, the Model H 70SD has a T-shaped handle intended for
downward chipping and demolishing. The compact Model H 70SD broadens our lineup of 90-class hammers
(T-shaped handle).
3. APPLICATIONS
Demolishing of concrete and similar materials
Groove and channel digging in concrete
Groove and channel digging in asphalt and gravel roads
Tamping/compacting of asphalt and graveled roads
Cuting of asphalt
[Typical applications]
Construction work, piping/wiring work, water supply/drain work, etc.
4. SELLING POINTS
Internal double-insulation construction
with sturdy aluminum frame
Dustproof double air vent construction
protects against concrete chips.
This hammer is specifically designed for downward
chipping and demolishing in the 65 --- 70 class.
More compact and lightweight than
90-class hammers (T-shaped handle)
T-shaped handle with shock
absorber reduces operator fatigue.
Tool retainer accepts 3 types of
28.5 mm (1-1/8") hex. shank tools

--- 2 ---
4-1. Selling Point Descriptions
4-1-1. Highest chipping and demolishing performance in its class
The powerful impact force of each blow ensures efficient and easy demolition of concrete. The demolition
performance is 1.0 --- 1.3 times more powerful than that of similar products.
4-1-2. T-shaped handle with shock absorber reduces operator fatigue
The T-shaped handle is equipped with the Hitachi's original shock absorber. Vibration transmitted from the tool
main body is effectively absorbed and vibration transmitted to handle (B) and the side handle is minimized by
compressing and shearing the two blocks of rubber mounted between the housing and handle (B) and between
the housing and the side handle. The T-shaped handle improves downward chipping and demolishing
performance and reduces operator's fatigue for a long-time operation.
4-1-3. Dustproof double air vent construction protects against concrete chips
A fine mesh is mounted between the tail cover and the housing which act as the air vent (inlet) for the motor
cooling fan. The double air vent construction prevents concrete chips from entering in the motor directly (Fig. 1).
Cooling air
Housing Tail cover
Mesh
Tail cover Housing
Concrete chip
Cooling air
Ratio of demolished weight (%)
100
100
79
Maker •Model
HITACHI H 70SA •H70SD
HITACHI H 65SD
C
Fig. 1

--- 3 ---
4-1-4. More compact and lightweight than 90-class hammers (T-shaped handle)
The Model H 70SD is lighter than the 90-class hammers (T-shaped handle) by 9 to 12 kg (19.8 to 26.5 lbs.) in
weight and shorter by 96 to 137 mm (3-25/32" to 5-13/32") in length since it has been developed based on the
current Model H 65SD which features the use of 3 types of 28.5 mm (1-1/8") hex. shank tools.
4-1-5. Tool retainer accepts 3 types of 28.5 mm (1-1/8") hex. shank tools
Three types of shank tools (Fig. 2) can be used in the Model H 70SD by turning the tool retainer in the following
two methods.
Fig. 2
Air tool shank tool Retaining groove tool
without collar
Stanard hex. shank
tool (combo type)
Fig. 3
(1) Mounting air tool shank tools and standard hex. shank tools (combo type)
(2) Mounting standard hex. shank tools (combo type) and retaining groove tools without collars
Fig. 4
Maker •Model
HITACHI H 70SD
HITACHI H 70SA
HITACHI H 90SC
HITACHI H 90SE
B
C
Weight
20 kg (44.1 lbs.)
18 kg (39.7 lbs.)
32 kg (70.5 lbs.)
32 kg (70.5 lbs.)
29 kg (63.9 lbs.)
29 kg (63.9 lbs.)
Overall length
722 mm (28-7/16")
625 mm (24-5/8")
842 mm (33-5/32")
859 mm (33-13/16")
845 mm (33-1/4")
818 mm (32-7/32")

--- 4 ---
No-load
Full-load
Power source
Voltage (V)
Motor type
Insulation structure
Enclosure Material
Paint
Switch
Type of handle
Full-load current
Power input
Striking speed
Weight
Packaging
Standard accessories
5. SPECIFICATIONS
H 70SD
Single-phase AC 50/60 Hz
110, 230, 240
AC single-phase series commutator motor
Double insulation
Aluminum alloy die casting, cast aluminum alloy,
glass-fiber reinforced plastic resin
Hammer-net silver green and black
Trigger switch
T-shaped handle
11.8 A (110 V), 5.7 A (230 V), 5.4 A (240 V)
1,240 W (for Australia only 1,400 W)
1,850 /min.
1,400 /min.
20.0 kg (44.1 lbs.); excluding cord
22.0 kg (48.5 lbs.)
Corrugated cardboard box
Hex. bar wrench (for M8) •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Hex. bar wrench (for M4) ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Item
Product
Packed

--- 5 ---
+
+
5-1. Optional Accessories
(1) Bull point
2. Grooving and chiseling work
(1) Cold shisel
Overall length
410 mm (16-9/64")
Code No.
996372
+
3. Cutting and stripping work (asphalt cutting, etc.)
(1) Cutter
4. Digging (substitute pick-ax)
+
Code No.
985233
Overall length
546 mm (21-1/2")
(1) Scoop
Code No.
996373
985231
Overall length
410 mm (16-9/64")
520 mm (20-15/32")
Overall length
410 mm (16-9/64")
520 mm (20-15/32")
Width
75 mm (3")
75 mm (3")
Code No.
996374
985232
1. Demolition work

--- 6 ---
(Note)
Code numbers listed above are subject to change. Please refer to periodic Technical News Bulletins.
5. Grease for impact drill
500 g (1.1 lbs.) Can 30 g (1 oz) Tube
70 g (2.5 oz) Tube
Code No. 981840
Code No. 308471Code No. 980927

--- 7 ---
W
min-1
mm
mm
mm
kg
dB(A)
dB(A)
m/s
2
---
J
---
---
A
B
C
6. COMPARISONS WITH SIMILAR PRODUCTS
6-1. Specification Comparisons
* For Australia only 1,400 W
C
C
B
Maker
Model name
Power input
Full-load impact rate
Dimensions
Striking energy per stroke
Insulation structure Double
insulation
85.0
102.1
14.0
20.0
(44.1 Ibs.)
Double
insulation
85.0
102.1
14.0
18.0
(39.7 Ibs.)
HITACHI
H 70SD
1,240*
1,400
722
(28-7/16")
554
(21-13/16")
237
(9-5/16")
42.0
H 70SA
1,240*
1,400
625
(24-5/8")
554
(21-13/16")
237
(9-5/16")
42.0
Lubricating method
No-load noise level
Vibration-absorbing handle
Full-load noise level
Vibration level
Weight (without cord)
GreaseGrease
Provided Provided
(illustration
below)
A
A
B
H 65SD
Double
insulation
102.2
18.0
(39.7 Ibs.)
823
(32-13/32")
1,240*
1,400
42.0
--- (
120
(4-23/32")
87.0
19.0
Grease
Provided
235
(9-1/4")
Double
insulation
101.9
17.0
(37.5 Ibs.)
613
(24-1/8")
C
1,240
1,200
46.8
--- (
520
(20-15/32")
93.5
20.0
Grease
Not provided
225
(8-7/8")
H 65SD

--- 8 ---
6-2. Demolition Performance Comparisons
The data shown in Fig. 5 are obtained in actual factory tests, and are for reference only. The demolished amount
may vary in accordance with operating conditions, operator skill, etc.
Fig. 5
7. PRECAUTIONS IN SALES PROMOTION
In the interest of promoting the safest and most efficient use of the Model H 70SD Electric Hammer 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 Caution 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
safety 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 Electric Hammer 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
The Model H 70SD unit is provided with a Nameplate (illustrated below) which lists basic safety precautions in its
use. Carefully ensure that the customer fully understands and follows these precautions before using the tool.
For Australia
250 Demolished amount
(kg/30 min.)
200
150
100
At rated
voltage
H 70SD
•
H 70SA
H 65SD
C161 (355 lbs.)
203 (448 lbs.)
203 (448 lbs.)
Demolished weight for 30 min. (kg)

--- 9 ---
7-3. Grease Replacement
Different kinds of grease are used in the electro-pneumatic hammering section and the speed-change gear
section. It is not necessary to replenish the grease between 6-month (approx.) change intervals unless the tool is
disassembled or there is grease leakage due to a damage or worn seal.
To ensure the smooth reciprocating of the striker and the second hammer, special grease (Part No. 980927
or 981840 or 308471 for impact drill) is used in the hammering section. If the hammering section [inside
the cylinder case and housing (crank shaft side)] is disassembled, thoroughly wipe away all old grease
from all parts, and apply 30 g (1 oz) of new grease within the cylinder case and 40 g (1.4 oz) of new grease
within the housing (crank shaft side). Do not exceed the designated amounts of grease. If there is
excessive grease, it may flow between the striker and piston and cause reduced hammering efficiency
and/or increased recoil force.
N.P.C. SEP-3A (Part No. 930035) is used in the speed-change gear section (inside the gear cover). The proper
supply amount is 80 g (2.8 oz). Never use the hammering section special grease in the speed-change section.
The special soft grease would leak into the motor section and cause serious problems.
7-4. O-Ring Replacement
The O-ring mounted on the piston is extremely important to ensure adequate sealing of the air pressure.
Although the O-ring is made of special rubber to ensure a long service life, it does nonetheless become worn and
should be replaced periodically depending on frequency of tool use. With average use, it is recommended that
the O-ring should be replaced every six months to ensure maximum effectiveness.

--- 10 ---
8. REFERENCE INFORMATION
8-1. Sealed and Dustproof Construction
The cylinder case section and housing (crank case side) are sealed by four (4) O-rings, a holder seal and a seal
ring. These seals serve to prevent leakage of the grease, as well as to prevent dust and dirt from entering the
mechanism.
Fig. 6
Housing
Seal ring
Cylinder case
O-ring
(64.4 mm (2-17/32") inner dia.)
Holder seal
O-ring
(23.7 mm (15/16") inner dia.)
O-ring (44.4 mm (1-3/4") inner dia.)
O-ring
(59.6 mm (2-11/32") inner dia.)
Gear cover
8-2. Vibration-Absorbing Construction
(1) Vibration-absorbing construction
The handle holders which secure handle (B) and the side handle to the housing can be smoothly turned
thanks to the handle pins inserted in the slotted through holes at both sides of the housing. The handle pins
are supported by dampers (B) fitted into the slotted through holes so that they can be moved in the axial
direction of the tool. Two blocks of rubber (handle dampers (B)) are inserted between the housing and the
handle holder. By pressing the handle portion, the handle holder turns and handle damper (B) is compressed
and sheared according to the movement of the main body. Damper (B) is also compressed when it comes in
contact with the handle pin. Thus, vibration transmitted from the main body to the handle portion is minimized.
The four cylindrical rubbers (handle dampers) cushion the shock generated between the housing and the
handle holder when the handle holder returns to the original position. The T-shaped handle with shock
absorber improves downward chipping and demolishing performance and reduces operator's fatigue for a
long-time operation.

--- 11 ---
Side handle
Handle holder
Switch lever Housing
Fig. 7
Handle holder
Handle damper (B)
Damper (B)
Handle damper
Handle holder
Handle (A) (B)
Handle pin
Slotted through hole Damper (B)
Housing

--- 12 ---
(Note) For improved operability in chipping and breaking operations, it is recommended that operating force be
limited to the dead weight of the tool rather than pressing forcefully down on the handles. In keeping
with this, the handle pressing force at which the vibration-absorbing effect is maximum is set for
between 5 kg (11.0 lbs.) and 10 kg (22.0 lbs.). The customer should be cautioned to avoid pressing
fully down on the handles during operation.
Pressing force (load) (N)
Z
HITACHI H70SD
(2) Level of handle vibration in Z direction
The graph below illustrates the relationship between handle pressing force and handle vibration level in the Z
direction.
Z
126.0
125.0
124.0
123.0
121.0
122.0
49 98 147 196 245
Vibration level (dB)
C

--- 13 ---
Fig. 10 Fig. 11
Retainer
Front cover
Tool shank
Recessed portion
Fig. 8
8-3. Tool Retainer
Three types of shank tools (Fig. 2) can be mounted
to the Model H 70SD by turning the saddle-shaped
retainer.
(1) Mounting air tool shank tool and standard hex.
shank tool
Raise the retainer in A direction and insert
the tool shank into the hexagonal hole of the
front cover as far as it will go (Fig. 8). Put the
retainer back in position to fix the tool shank
(Fig. 9).
(2) Mounting standard hex. shank tool and retaining
groove tool without collar
Lower the retainer in B direction and insert
the tool shank into the hexagonal hole of the
front cover as far as it will go facing the
recessed portion of the tool shank to the
retainer (Fig. 10). Turn the retainer in C
direction to fix the tool shank (Fig. 11).
Front cover
Retainer
Tool shank
Fig. 9

--- 14 ---
Fig. 12
9. REPAIR GUIDE
9-1. Precautions and Suggestions for Disassembly and Reassembly of the Main Body
The [Bold] numbers in the descriptions below correspond to the item numbers in the Parts List and exploded
assembly diagram.
9-1-1. Disassembly
[NOTE] If it is difficult to loosen and remove the fixing bolts, use an appropriate heating device to heat them to
approximately 80˚C (176˚F).
Disassembly of the Armature Ass'y [88]
(1) Loosen the four Seal Lock Hex. Socket Hd. Bolts M4 x 12 [55], remove the Cap Covers [56], Cap Rubbers
[57] and Brush Caps [58], and take out the Carbon Brushes (Auto Stop Type) (1 Pair) [59]. At this time, be
very careful not to lose the disassembled parts.
(2) Loosen the four Nylock Hex. Socket Hd. Bolts M8 x 35 [21], and remove the Cylinder Case [18]. Next, after
loosening the Seal Lock Hex. Socket Hd. Bolt M8 x 16 [30], the Connecting Rod Ass'y [27] and Crank Washer
[29] can be disassembled. Leave the Striker [20] and Piston [25] as they are.
(3) Loosen the six Seal Lock Hex. Socket Hd. Bolts M6 x 45 [61], and disassemble the Gear Cover [32] and
Counter Gear [63]. Then, by inserting a flat-blade screwdriver or similar tool into one of the air vents of the
Inner Cover [36] and lifting it upwards, the Inner Cover [36], Armature Ass'y [88], Crank Shaft [41], and related
parts can be removed in a single body.
(4) As illustrated in Fig. 12, support the Inner Cover [36] with an appropriate tubular jig, and push down on the end
surface of the armature shaft with a hand press to separate the Armature Ass'y [88] from the Inner Cover [36].
Disassembly of the Crank Shaft [41] section
First, remove the four Seal Lock Hex. Socket Hd. Bolts M5 x 16 [40] which fix the Bearing Cover [39]. Then,
as illustrated in Fig. 13, support the lower surface of the Inner Cover [36] with an appropriate tubular jig,
align an appropriate steel rod with the end surface of the Crank Shaft [41], and press down on the steel rod
with a hand press. The Ball Bearing 6205DDCMPS2L [38], Distance Ring (B) [35], Final Gear [34], two
Woodruff Keys 4 x 16 [42], and Crank Shaft [41] can then be disassembled from the Inner Cover [36].
Inner Cover [36]
Crank Shaft [41]
Armature Ass'y [88] Tubular jig
Press the end surface of the armature shaft
with a hand press.

--- 15 ---
Disassembly of remaining parts from the Inner Cover [36]
Loosen the three Seal Lock Hex. Socket Hd. Bolts M5 x 16 [40], and take out Bearing Cover (A) [65] and the
Ball Bearing 6203DDCMPS2L [66].
Disassembly of the Mouth [14] and related parts
First, remove the six Nylock Hex. Socket Hd. Bolts M8 x 30 [4], and separate the Front Cover [6] from the
Cylinder Case [18]. The Second Hammer [8], Shank Sleeve [13], Damper (A) [12], Mouth [14], Mouth Cover
[15], Mouth Washer [16], and Urethane Ring [17] can then be taken out.
Removal of O-Ring (E) [11]
As O-Ring (E) [11] is installed in the inner portion of the Shank Sleeve [13], it may be difficult to remove. As
illustrated in Fig. 14, pry O-Ring (E) upward gently with a slender flat-blade screwdriver, being very careful
not to damage the surface of the O-ring.
Removal of the Striker [20] and related parts
Remove the four Nylock Hex. Socket Hd. Bolts M8 x 35
[21], and separate the Cylinder Case [18] from the
Housing Ass'y [103]. From the Cylinder Case [18],
take out the Striker [20], Piston [25], and Connecting
Rod Ass'y [27] in a single body.
Holding the Striker [20] firmly in one hand, grasp the
Connecting Rod Ass'y [27] in the other hand and pull it forcefully
to separate it from the striker. Finally, extract the Piston Pin [26]
from the Piston [25], and separate the Piston from the
Connecting Rod Ass'y [27].
Disassembly of Switch (A) (1P Screw Type) W/O Lock [98] and related parts
Pry off the Retaining Ring (E-Type) for D4 Shaft [71] with a small flat-blade screwdriver, pull out the Pin [69],
and remove the Switch Lever [70]. Then, remove the two Seal Lock Hex. Socket Hd. Bolts M6 x 30 [45] on
the Handle (B) side and the two Tapping Screws (W/Flange) D4 x 20 (Black) [102], and remove Handle (B)
[101].
Fig. 13
Press the end surface of the Crank Shaft
by fitting a steel rod with a hand press.
Final Gear [34]
Tubular jig
Crank Shaft [41]
Inner Cover [36]
Ball Bearing 6302VVCMPS2L [33]
Fig. 14
O-Ring (E) [12] Slender
flat-blade
screwdriver
Shank
Sleeve [14]

--- 16 ---
Remove the two Roll Pins D6 x 55 [2] from the 6 mm dia. holes of the Retainer [1] and remove the Lever Pin
[3]. The Retainer [1] and two Retainer Dampers [5] can then be removed from the Front Cover [6] (Fig. 15).
Fig. 15
Front Cover [6]
Retainer Dampers [5]
(2 pcs.)
Retainer [1]
Lever Pin [3]
Roll Pins D6 x 55 [2] (2 pcs.)
Disassembly of the Retainer [1] section

--- 17 ---
9-1-2. Reassembly
Reassembly can be accomplished by following the disassembly procedures in reverse. However, special
attention should be given to the following items.
Reassembly of the Crank Shaft [41] section
Press-fit the Ball Bearing 6205DDCMPS2L [38] into the Inner Cover [36], and fasten the Bearing Cover [39]
onto the Inner Cover [36] with the four Seal Lock Hex. Socket Hd. Bolts M5 x 16 [40]. Support the inner race
of the Ball Bearing 6205DDCMPS2L [38] with an appropriate jig, and press-fit the Crank Shaft [41] into the
Ball Bearing. Next, insert Distance Ring (B) [35] and two Woodruff Keys 4 x 16 [42] into the Crank Shaft [41],
and press-fit the Final Gear [34] and Ball Bearing 6302VVCMPS2L [33] with a hand press.
Reassembly of the Armature Ass'y [88]
Press-fit the Ball Bearing 6203DDCMPS2L [66] into the Inner Cover [36], and fasten Bearing Cover (A) [65]
onto the Inner Cover with the three Seal Lock Hex. Socket Hd. Bolts M5 x 16 [40].
Reassembly of the Striker [20] (Two possible methods)
(1) After the Connecting Rod Ass'y [27] has been
assembled into the Housing Ass'y [103], mount the
Piston [25] and press it into the Striker [20].
(2) Mount the Piston [25] onto the Connecting Rod
Ass'y [27], and push down on the Connecting
Rod Ass'y to press the Piston into the Striker [20].
Either of the two methods described above requires a pressing force of more than 30 kg. When a "hissing"
sound is heard, the Piston [25] is properly inserted in the Striker [20]. (The "hissing" is the sound of the
compressed air escaping from the Striker [20] when the Piston [25] reaches the respiratory chambers within
the Striker [20].)
Fig. 16
Connecting Rod Ass'y [27] Striker [20]
Respiratory holes
Piston [25]
Respiratory holes
Piston [25] Striker [20]
Connecting Rod Ass'y [27]
Housing Ass'y [103]

--- 18 ---
Reassembly of the Handle Holder [47] section
Mount four Dampers (B) [43] and four Handle Dampers [49] to the Housing Ass'y [103], then mount two
Handle Dampers (B) [48] to the Housing Ass'y [103] in the direction of arrow marked on Handle Damper (B)
[48] surface. Next, mount two Handle Holders [47] to the Housing Ass'y [103] and insert two Handle Pins
[92] into two 17.5 mm dia. holes of the Handle Holders [47]. Finally, tighten two Seal Lock Hex. Socket Hd.
Bolts M8 x 16 [30] with two Washers [100]. At this time, align the notch of the flange portion of the handle pin
with the notch of the Handle Holder [47] and then hold the flange portion of the Handle Pin [92].
Fig. 17
Handle Damper (B) (2 pcs.) [48]
Handle Holder (2 pcs.) [47]
Damper (B) (4 pcs.) [43]
Handle Pin (2 pcs.) [92]
Washer (2 pcs.) [100]
17.5 mm dia. holes
Handle Damper (4 pcs.) [49]
Housing Ass'y [103]
Seal Lock Hex. Socket Hd. Bolt M8 x 16 (2 pcs.) [30]