Hitachi NV 50AF3 Manual

TECHNICAL DATA
AND
SERVICE MANUAL
COIL NAILER
NV 50AF3
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No.: E019 Jan. 2005
N
MODEL
NV 50AF3
Hitachi 
Power Tools

CONTENTS
Page
1. PRODUCT NAME ............................................................................................................................ 1
2. MARKETING OBJECTIVE .............................................................................................................. 1
3. APPLICATIONS ............................................................................................................................... 1
4. SELLING POINTS ........................................................................................................................... 1
4-1. Selling Point Descriptions ................................................................................................................ 2
5. SPECIFICATIONS ........................................................................................................................... 3
5-1. Specifications ....................................................................................................................................3
5-2. Nail Selection ....................................................................................................................................4
5-3. Nail Driving Force .............................................................................................................................6
5-4. Optional Accessory ...........................................................................................................................7
6. PRECAUTIONS IN SALES PROMOTION ...................................................................................... 8
6-1. Safety Instructions ............................................................................................................................8
6-2. Related Laws and Regulations .........................................................................................................9
6-3. Precautions in Sales Promotion ........................................................................................................9
7. MECHANISM AND OPERATION PRINCIPLE .............................................................................. 10
7-1. Mechanism .....................................................................................................................................10
7-2. Operation Principle .........................................................................................................................12
8. TROUBLESHOOTING................................................................................................................... 14
8-1. Troubleshooting and Correction ......................................................................................................14
8-2. Possible Causes and Corrections for Air Leakage .........................................................................19
9. DISASSEMBLY AND REASSEMBLY ........................................................................................... 21
9-1. General Precautions in Disassembly and Reassembly ..................................................................21
9-2. Disassembly and Reassembly of the Output Section .....................................................................22
9-3. Disassembly and Reassembly of the Control Valve Section ..........................................................24
9-4. Disassembly and Reassembly of the Cap and the Magazine Section ........................................... 27
9-5. Disassembly and Reassembly of the Driving Section .................................................................... 29
10. INSPECTION AND CONFIRMATION AFTER REASSEMBLY ................................................... 33
11. STANDARD REPAIR TIME (UNIT) SCHEDULES....................................................................... 34
Assembly Diagram for NV 50AF3

--- 1 ---
1. PRODUCT NAME
Hitachi Coil Nailer, Model NV 50AF3
2. MARKETING OBJECTIVE
The Model NV 50AF3 is a lightweight coil nailer that can handle wire-collated nails with lengths of 27 mm
(1-1/16") to 50 mm (2") and sheet-collated nails with lengths of 25 mm (1") to 45 mm (1-3/4"). This model's
outstanding features are as follows.
Small and lightweight [1.4 kg (3.1 lbs)]
Exhaust muffler for reduction of exhaust noise and dust disturbance
New magazine with a tilt bottom for easy top loading
Nailing depth adjustment mechanism with an easy-to-see calibrated dial
3. APPLICATIONS
* General nailing for construction such as nailing of a variety of backing materials, such as plywood or drywall.
* Fastening of a variety of interior finishing materials
* Nailing of a variety of architectural metals, such as reinforcing brackets [0.35 m (0.014") or less in thickness]
for joining frames or rafters of wooden buildings
4. SELLING POINTS
Newly designed magazine
for easy nail top loading
with tilt bottom
Continuous nailing/single
nailing changeover capability
[For Europe, by turning the
lever with the accessory hex.
bar (allen) wrench]
Exhaust muffler:
Reduces exhaust noise
Flings up less dust
Top cover swivels 360 for
precise, one-touch exhaust
air control
Nailing depth adjustment
mechanism with an easy-
to-see calibrated dial
Equipped with a handle grip
Protector
Small and lightweight
1.4 kg (3.1 lbs)
Automatic changeover between
wire-collated nails and sheet-collated
nails for stabler nail driving

--- 2 ---
The nailing depth can be changed by 0.5 mm per click.
The adjustable range of nailing depth is from 0 mm to 0.5 mm.
4-1. Selling Point Descriptions
(1) Magazine
(a) Tiltable
The nail holder can be tilted for easy nail loading.
[Reference]
Adjust the nail holder according to the length of nails to be used
as shown below.
1 Turn the nail holder about 90 counterclockwise.
2 Adjust the upper surface of the nail holder to a desired mark on
the inside of the magazine according to the length of nails to be
used by sliding the nail holder vertically.
3 Turn the nail holder clockwise until a click is heard (about 90 ).
(2) Nailing depth adjustment mechanism
The Model NV 50AF3 is equipped with a nailing depth adjustment mechanism that enables adjustment of
nailing depth by turning the adjuster dial.
However, an air pressure which exceeds the proper level for the driving resistance of the nails can shorten the
service life of the coil nailer. Be sure to instruct customers to adjust both the air pressure level and the
adjuster dial by referring to the table below.
Adjust the adjuster dial and the air pressure level referring to the
table below.
Perform a test driving. When the nail head is sunk below the
wood surface, adjust the adjuster dial clockwise (Up).
When the nail head is left above the wood surface, adjust the air
pressure level to higher.
Proper
Nail head is
lower than the
surface. (Turn
the adjuster dial
clockwise (Up).)
Nail head is
higher than the
surface. (Turn the
adjuster dial
counterclockwise
(Down).)
Adjuster dial
Up
Down
Nail holder
Magazine
Magazine
cover
Nail holder
For 27 mm
For 32, 38 mm
For 45, 50 mm
Magazine
Nail
Reference of air pressure and adjuster dial setting
Nail length Air pressure Adjuster dial
27 mm to 32 mm
38 mm to 50 mm
4.9 bar (5 kgf/cm2,, 70 psi)
6.9 bar (7 kgf/cm2, 98 psi)
Fully turn the adjuster
dial counterclockwise
for the lowermost level.

--- 3 ---
Sequential fire parts set (Code No. 881012)
Pneumatic tool lubricant [30 cc (1 oz) oil feeder] (Code No. 877153)
Pneumatic tool lubricant [120 cc (4 oz) oil feeder] (Code No. 872042)
Pneumatic tool lubricant [1 ltr (1 quart) can] (Code No. 876212)
Grease (ATTOLUB No. 2) [500 g (1.1 lbs.)] (Code No. 317918)
5. SPECIFICATIONS
5-1. Specifications
Model
Driving system
Applicable pressure
Driving speed
Product weight
Main body dimensions
(Length x Height x Width)
Nail feed system
Nail capacity
Air consumption
Air inlet
Packaging
Package dimensions
(Length x Height x Width)
Standard accessories
Optional accessories
NV50AF3
Reciprocating piston type
4.9 --- 8.3 bar (5 --- 8.5 kgf/cm2, 70 --- 120 psi) (Gauge pressure)
3 pcs./sec
1.4 kg (3.1 lbs)
252 mm x 269 mm x 112 mm
(9-15/16" x 10-19/32" x 4-13/32")
Reciprocating piston type
0.80 liter/cycle at 6.9 bar
(0.80 liter/cycle at 7 kgf/cm2)
(0.28 ft3/cycle at 100 psi)
3/8 NPT thread
Corrugated cardboard box (Sleeve type)
310 mm x 350 mm x 135 mm
(12-3/16" x 13-25/32" x 5-5/16")
Safety glasses (Code No. 875769) ••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Hex. bar wrench for M4 screw (Code No. 943277) ••••••••••••••••••••••••••• 1
Hex. bar wrench for M5 screw (Code No. 944458) ••••••••••••••••••••••••••• 1
Hex. bar wrench for M6 screw (Code No. 944459) ••••••••••••••• •••••••••••• 1
Oiler (30 cc) (Code No. 877153) ••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Case (Code No. 881849) ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Nose cap (A) (Code No. 881092) •••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Nose cap (B) (Code No. 881093) •••••••••••••••••••••••••••••••••••••••••••••••••••• 1
200 --- 400 nails

--- 4 ---
Wire-collated nails
Min. Max.
Fig. 1 Dimensions of nails
5-2. Nail Selection
The Model NV 50AF3 utilizes common round-head nails collated by wire or sheet into coils from 200 to 400
pieces. Applicable nail dimensions are shown below. However, it is recommended to use genuine HITACHI nails
to ensure satisfactory driving quality.
CAUTION: Ensure that nails are as specified in Figs. 1, 2 and 3. Other nails will cause clogging of nails
and subsequent damage to the nailer.
NOTE: Aluminum nails may bend when driven into a hard workpiece. Test before use.
4.6 mm
(0.181")
4.8 mm
(0.189")
2.3 mm
(0.091")
1.8 mm
(0.071")
27 mm (1-1/16")
50 mm (2")
Sheet-collated nails
Min. Max.
4.6 mm
(0.181")
5.2 mm
(0.205")
2.0 mm
(0.079")
1.6 mm
(0.063")
25 mm (1")
45 mm (1-3/4")

--- 5 ---
Ld1
27 --- 50
(1-1/16 --- 2)
12
(0.472)
Unit: mm (inch)
dL
1L2D1D2H
1.8 --- 2.3
(0.071 --- 0.091)
24
(0.98)
22
(0.866)
100
(3.937)
72
(2.835)
0.6
(0.024)
Fig. 2 Dimensions of wire-collated nails
Fig. 3 Dimensions of sheet-collated nails
4.5
(0.177)
0.8
(0.031)
12.5
(0.492)
9.7
(0.382)
14
(0.551)
6
(0.236)
6
(0.236)
L
25 --- 45
(1 --- 1-3/4)
dD1D2H
1.6 --- 2.0
(0.063 --- 0.079)
25
(1)
98
(3.858)
47
(1.85)

--- 6 ---
5-3. Nail Driving Force
Figure 4 shows the energy required to drive a nail flush and the output energy of the NV 50AF3 nailer.
When the supplied pressure is adjusted so that the output energy of the nailer equals the energy required for
driving a nail, the nail can be completely driven.
For example, in driving wire-collated nails of 2.1 mm dia. x 50 mm length (0.080" dia. x 2" length) into Hemlock
below a 12 mm plywood sheet with the Model NV 50AF3, a force of about 5.3 bar (5.6 kgf/cm2, 79.8 psi) is
required to drive the nail flush with the surface of the plywood. If the nail is driven with a force more than 5.5 bar
(5.6 kgf/cm2, 79.8 psi), the nail head will be sunk below the wood surface. Please use Fig. 4 as a rough guide
only, because figures vary according to the workpiece materials, moisture content, and grain of the wood.

--- 7 ---
Fig. 4 Required nailing energy and nailer output energy
5-4. Optional Accessory
Sequential fire parts set:
The sequential fire parts set is provided as an optional accessory for the Model NV 50AF3. By using this optional
accessory, a nail is driven by pressing the pushing lever first against a workpiece and then pulling the trigger, and
no nail is driven when pulling the trigger first and then pressing the pushing lever against a workpiece (single-shot
operation). Please recommend the sequential fire parts set to the customers who want to use it. Salespersons
must instruct the customers to read the Handling Instructions attached to the sequential fire parts set and also the
Handling Instructions of the Model NV 50AF3 thoroughly for correct use.
4 5 6 7 8
4 5 6 7 8
60 70 80 90 100 110 120
Air pressure setting to drive nail flush
with NV50AF3
Nail: d x L
(
mm x mm )
d
L
2.3 mm x 50 mm
(0.091" x 2")
bar
kgf/cm
2
PSi
2.1 mm x 50 mm
(0.083" x 2")
1.8 mm x 27 mm
(0.071" x 1-1/16")
Size of nail
40 60 80 100 120 140
mm
2
in
2
50
40
30
20
10
50
40
30
20
10
500
400
300
200
100
500
400
300
200
100
40
30
20
10
40
30
20
10
(ft-Ibs) (J)
(kgf cm)
(ft-Ibs) (J)
(kgf cm)
Nailer output energy
Required nailing energy
0.05 0.1 0.15 0.2
Hemlock + 12mm (0.47") plywood Output range of
NV50AF3

--- 8 ---
6. PRECAUTIONS IN SALES PROMOTION
6-1. Safety Instructions
In the interest of promoting the safest and most efficient use of the Model NV 50AF3 Nailer 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 Warning Label attached to each tool.
(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 pneumatic tool cannot be completely eliminated.
Accordingly, specific precautions and suggestions for the use of the pneumatic nailer are listed in the Handling
Instructions to enhance the safe and 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.
(2) Warning Label
Each Model NV 50AF3 unit is provided with a Warning Label (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.
GEFAHR Vor Gebrauch die BETRIEBSANLEITUNG LESEN. Ein Nichtbeachten
der Betriebsanleitung KANN ZU ERNSTHAFTEN VERLETZUNGEN FÜHREN.
Anwender und andere Personen, die sich im Arbeitsbereich aufhalten, MÜSSEN
DIE ERFORDERLICHEN SCHUTZBRILLEN TRAGEN.
NIEMALS FLASCHENGASE BENUTZEN. Ausschließlich regulierte Druckluft benutzen.
ÜBERSCHREITEN SIE NIEMALS 120 psi/8.3 bar. TRAGEN SIE DIE MASCHINE
NIEMALS MIT DEM FINGER AM SCHALTER. Vor Service-und Reparaturarbeiten,
sowie wenn das Gerät nicht benutzt wird, DRUCKSCHLAUCH ABKLEMMEN.
DANGER LISEZ LE MANUEL D'UTILISATION avant usage. VOUS POUVEZ
VOUS BLESSER GRAVEMENT en ne suivant pas les instructions. L'opérateur ainsi
que toute personne à aproximité DOIT PORTER DES LUNETTES DE SECURITE
AGREES. NE JAMAIS UTILISER DU GAZ EMBOUTEILLE. Utiliser uniquement de
l'air règlé. NE PAS DEPASSER 12 psi/8.3 bar. NE JAMAIS PORTER AVEC LE
DOIGT SUR LA GACHETTE. DEBRANCHEZ L'AIR avant de commencer l'entretien,
le règlade ou avant d'arrêter le travail.
C316007

--- 9 ---
6-2. Related Laws and Regulations
As nailers and staplers are designed to instantaneously drive nails and staples, there is an ever-present danger of
misfiring and subsequent possible serious injury. Accordingly, close attention in handling is absolutely necessary
at all times. Carefully ensure that the customer is fully aware of the precautions listed in the Handling Instructions
provided with each unit.
While there are no specific safety regulations, there are related items in various general safety regulations with
which the salespersons should be familiar in order to advise the customer properly. Please check your national
and/or local regulations for applicable items.
Some applicable items are outlined below.
(1) Europe
EUROPEAN STANDARD EN792-13 JUNE 2000
HAND-HELD NON-ELECTRIC POWER TOOLS---SAFETY REQUIREMENTS
Part 13: Fastener driving tools
(2) The U.S.A.
OSHA 1926.102 Eye and Face Protection
1926.302 Power-Operated Hand Tools
ANSI SNT-101-2002 Portable, Compressed-Air-Actuated,
Fastener Driving Tools---Safety Requirements for
6-3. Precautions in Sales Promotion
The salespersons must instruct customers to observe the following precautions.
(1) An air pressure less than 4.4 bar (4.5 kgf/cm2, 63 psi) or more than 7.8 bar (8 kgf/cm2, 112 psi) can affect the
performance, service life and safety of the Model NV 50AF3. Pay special attention to the pressure level,
capacity and piping of the air compressor. [If using an air compressor capable of high air pressure [9.8 bar
(10 kgf/cm2, 140 psi) or more], be sure to install a pressure reducing valve on the air compressor and limit the
pressure to 7.8 bar (8 kgf/cm2, 112 psi) or less.]
(2) To protect the Model NV 50AF3 against rust, apply oil and perform idle driving two or three times to spread the
applied oil fully inside this nailer when it is not used for a long time. Also coat the steel parts with oil.
(3) Rust inside this nailer can cause performance degradation or failure. The salespersons must instruct the
customers to drain the air compressor tank without fail.
(4) The salespersons must instruct the customers, especially those who use the Model NV 50AF3 frequently, to
check and maintain this nailer without fail.
(5) The salespersons must instruct the customers to clean and apply the provided oil to the sliding sections of the
pushing lever regularly.

--- 10 ---
7. MECHANISM AND OPERATION PRINCIPLE
7-1. Mechanism
Most of the parts of the Model NV 50AF3 have been newly designed, though the basic construction is the same
as that of the Model NV 38AB2. Features of the main parts are described below.
Output section .................. Most of the parts have been newly designed, though the basic construction is the same
as that of the Model NV 38AB2.
The muffler has been added to reduce air exhaust force.
Control valve section ........ This section is common to that of the Model NV 38AB2.
Driving section.................. The adjuster, nose, nail guide and other parts have been newly designed for
improvement of operability in nailing depth adjustment.
Magazine section ............. Most of the parts have been newly designed for easier nail loading.

--- 11 ---
Top cover
Cylinder
Piston bumper
Pushing lever (A)
Head valve
Exhaust cover
Control valve ass'y
Plunger spring
Plunger (A)
Valve
bushing (B)
Valve bushing (A)
Control valve ass'y
Feeder (Feed claw)
Nail guide
Feed piston
Nail holder
Magazine cover
Guide lock
A
Fig. 5 Construction
Cross section A --- A
Exhaust port
Head ring
Muffler
Protector(A)
Piston
(Driver blade)
Body
Feeder
(Feed chuck)
Adjuster
Nose
Ejection port
Vinyl cover
(Dust proof cover)
Magazine
Hook
Valve piston (B)
Change knob (B)
Trigger (A)
Magazine section
Output section
Driving section

--- 12 ---
(1) Prior to nailing (See Fig. 6.)
1. When compressed air is supplied to the main body,
it fills the accumulator (see diagram).
2. At the same time, the compressed air flows into the
valve piston lower chamber of the control valve
section, and pushes up the valve piston. Also, the
compressed air flows from the air supply vent,
through air passage (A), and into the head valve
upper chamber where it simultaneously pushes
down the head valve and the head valve spring to
seal the upper surface of the head valve and the
cylinder.
(2) During nailing (I) (See Fig. 7.)
1. When plunger (A) is pushed up by operating both
the pushing lever and trigger (A), the compressed
air in the valve piston lower chamber is exhausted
from the lower part of plunger (A). Then, the valve
piston is pushed down by the compressed air from
the accumulator so that it shuts off the air supply
vent and releases the exhaust valve.
2. When the exhaust valve opens, the compressed air
in the head valve upper chamber is exhausted into
the atmosphere through air passage (A).
3. The air pressure applied against the lower surface
of the head valve soon exceeds the force of the
head valve spring, and pushes the head valve up.
The head valve is pushed fully upward by the
compressed air, and seals the upper surface of the
exhaust cover and the head valve.
4. When the head valve is pushed up, the
compressed air flows rapidly into the cylinder and
pushes down the piston to drive a nail. At this time,
the compressed air flows through the cylinder hole,
into the return air chamber, through air passage (B),
and into the chamber at the left side of the feed
piston in the nail feeder section. When the air
pressure exceeds the force of the feed spring, the
feeder moves to the right.
7-2. Operation Principle
Cylinder
Head valve spring Air passage (A)
Head valve Accumulator
Valve piston (B)
Control
valve
section
Air supply vent
Pushing
lever (A)
Fig. 6 Prior to nailing
Air supply vent
Fig. 7 During nailing (I)
Exhaust valve
Accumulator
Exhaust cover
Air passage (A)
Head valve spring
Head valve
Cylinder
hole
Piston
Cylinder
[Return air
chamber]
Air passage
(B)
Plunger (A)
Trigger (A)
Pushing
lever (A)
Valve piston
Nail feeder
section
Feed spring
Feed piston
Feeder
Pushing lever (B)

--- 13 ---
(3) During nailing (II) (See Fig. 8.)
1. When the piston moves down inside the cylinder,
the air below the piston flows through air passage
(C) under the cylinder and is accumulated in the
return air chamber together with the compressed air
flowing through the cylinder hole.
2. When the compressed air in the left chamber of the
feed piston moves the feed piston fully to the right,
the nail feeder (feed pawl) engages the next nail.
(4) After nailing (See Fig. 9.)
1. When the trigger is released, the plunger goes
down, the air supply vent opens, the valve piston
goes up, and the compressed air in the
accumulator passes through air passage (A) into
the head valve upper chamber. The head valve is
then pushed down by the head valve spring and the
air pressure against the upper surface of the head
valve. At the same time, the exhaust valve opens
and the upper chamber of the cylinder is opened to
the atmosphere.
2. When the head valve seals the upper surface of the
cylinder, the compressed air accumulated in the
return air chamber passes through air passage (C),
presses on the lower surface of the piston, and
forces the piston to return upward to its original
position. Also, the compressed air above the piston
is exhausted through the head valve hole.
3. The compressed air accumulated in the left
chamber of the feed piston passes through air
passage (B), goes into the return air chamber, and
is then exhausted through the nose hole. The feed
piston is then moved to the left by the force of the
feed spring, and the feed pawl feeds the next nail
into the ejection port. This completes one full
nailing cycle.
Cylinder
[Return air
chamber]
Air passage
(C)
Piston
Nail feeder
Cylinder hole
Fig. 8 During nailing (II)
[Return air
chamber]
Piston
Head valve spring
Head valve
Cylinder
Air passage (A)
Fig. 9 During return
Feed piston
Nail feeder
Air passage (C)
Feed piston
Feed spring
Plunger (A)
Trigger
Valve piston
Air supply vent
[Accumulator]

--- 14 ---
* The air passage is jammed
(with pieces of broken
piston bumper etc.).
* The feed piston chamber
contains foreign matter
such as pieces of broken
bumper etc.
Remove foreign matter.
Replace the piston bumper
with new one.
Body....Remove foreign matter
in the return air chamber.
Nose....Remove foreign
matter in the air passage and
the feed piston chamber.
8. TROUBLESHOOTING
8-1. Troubleshooting and Correction
Fault Cause
( The mark * refers to main causes. )Inspection method Remedy
(1)
Nails fail to
eject.
< Nail >
The nailer is loaded with
nails not approved by
Hitachi.
The nailer is loaded with
abnormal nails (bent nails,
nail heads too large, or too
small, abnormally collated
nails, deformed wire).
Nails or link pieces are
jammed.
Deformation and breaking
of collated nails
Check whether or not the
nailer is normally loaded with
nails approved by Hitachi.
Use specified nails.
Remove abnormal nails and
load the nailer with proper
nails.
< Nail feeding section:
nose, feeder,
feed piston, etc. >
The sliding resistance of
the feed piston is too great.
The nail guide face of the
nose is abnormal
(deformed, jagged,
damaged and/or worn).
The feed spring and/or
feeder spring is abnormal
(damaged and/or fatigued).
The feeder is abnormal
(damaged and/or worn).
Remove the feed piston, and
examine the feed piston slide
surface of the nose.
Apply grease.
Polish the scratched section
with abrasive paper.
Replace parts.
Check whether or not the nail
feeding section is abnormal
(jagged, deformed, damaged
or worn).
Replace parts.
Smooth jagged areas.
Correct the deformed part.
The nose is not correctly
loaded with nails in the
groove.
Check whether or not the
nailer is correctly loaded with
nails in the specified groove.
Load the nailer with nails in
the correct position in the
nose.
Insufficient oil and/or dust
sticking in the chuck
groove's slide of the nose.
Remove dust and then apply
oil.
Air pressure is too low. Adjust air pressure in a range
of 4.9 --- 8.3 bar (5 --- 8.5
kgf/cm2, 70 --- 120 psi).
Open the nail guide and inject
air to check the feeder's
action.

--- 15 ---
Replace parts.
Apply grease.
Replace the piston bumper
with new one.
Pushing lever (A)
* The piston bumper is
abnormal.
The inner face of the
cylinder is abnormal ( packed
with dust and/or worn ).
The sliding face of the head
valve is abnormal (seized,
damaged, and/or oil has
depleted).
Examine the action of pushing
lever (A).
Reassemble or replace the
O-ring with new one.
< Nail guide section >
The nail guide face of the
nail guide is abnormal
(deformed, jagged,
damaged and/or worn).
Air leaks from a gap
between the body and the
nose.
Fault Cause
( The mark * refers to main causes. )Inspection method Remedy
(1)
Nails fail to
eject.
(Continued)
Open the nail guide and inject
air to check feeder's action.
Tighten screws and examine
the O-rings (1AP-3).
O-rings are worn and
deformed.
Check whether or not the nail
guide is abnormal (jagged,
deformed and/or damaged).
Examine the O-ring.
Examine the action of nail
stopper (A) and nail stopper
(B).
Remove dust and then apply
oil.
Replace abnormal parts.
Collate the nails normally and
reload the nailer with normally
collated nails.
Remove burrs and deformed
parts and replace parts.
Adjust the height of the nail
holder correctly.
< Magazine section >
< Pushing lever (A) >
Magazine Check whether or not a nail
catches on another nail in the
magazine.
Check whether or not a nail
catches on some part of the
magazine.
Check the nail holder for the
height.
Correct or replace parts.
< Output section: Piston,
driver blade, etc. >
Air pressure is low. Adjust air pressure in the
range of 4.9 --- 8.3 bar (5 ---
8.5 kgf/cm2, 70 --- 120 psi).
* Piston rings are worn.
Open the nail guide and inject
air to examine whether or not
the driver blade is reset.
Replace the piston ring with
new one.
Examine whether or not nails
can be driven at a pressure of
4.9 bar (5 kgf/cm2, 70 psi).
Correct the driver blade or
replace it with new one.
The O-ring in the cylinder
section is abnormal (off,
jagged and/or damaged).
Inject air to check nail driving
action.
Remove dust and then apply
oil. Or replace the cylinder
with new one.
The driver blade is
abnormal ( deformed, jagged,
damaged and/or worn ).
The O-rings need oil. Apply grease or oil.
Correct and replace part.
Dust is stuck to the inside of
the nail guide groove, and
the oil in the groove has
depleted.
* A spring is abnormal (off,
damaged and/or fatigued).
The claw ridge section of
the nail stopper is abnormal
(damaged, worn and/or
jagged).

--- 16 ---
Disassemble the output
section and check whether or
not the piston ring, the O-ring
and the cylinder are normal.
* The piston ring is
abnormal (worn and/or
damaged).
The inner face of the
cylinder is abnormal (worn
and/or rough).
Inject air to check whether or
not the driver blade is left
lowered.
Nails are not completely fed
in the injection port.
Nails not approved by
Hitachi are used.
Replace parts.The spring of the head
valve is abnormal (fatigued
and/or damaged).
Inject air to check whether or
not the driver blade is left
lowered.
Fault Cause
(
The mark * refers to main causes. )Inspection method Remedy
(1)
Nails fail to
eject.
(Continued) < Control valve section >
Plunger (A), valve piston
(B), valve bushing (A) and
valve bushing (B) are
abnormal (seized and/or
damaged).
Disassemble the control valve
and check the O-rings.
Apply grease or replace it.
Refer to Item 1. Refer to Item 1.
Check whether or not the
driver blade head is
abnormally worn.
Replace it.
Nails not approved by
Hitachi are used.
Check whether or not the nail
is appropriate for metal
reinforcing plates.
Use nails approved by Hitachi.
Adjust air pressure in the range
of 4.9 --- 8.3 bar (5 --- 8.5 kgf/
cm
2
, 70 --- 120 psi) .
Replace the abnormal parts.
(2)
Nails are
driven bent.
The wood being nailed is
very hard.
Check whether or not the nail
is bent, even when it is driven
into soft wood.
The nailer cannot be used
because the material is
beyond its applicable range.
(3)
Nails cannot
be driven
into the
wood
completely:
the heads
cannot be
made flush.
The adjuster is incorrectly
set.
Try to drive nails with the
adjuster set to maximum
depth.
Adjust the adjuster to the
optimum depth.
Check whether or not the nail
heads are flush with the
surface when driven into soft
wood.
The nailer cannot be used
because the material is
beyond its applicable range.
Inject air and check whether
or not the driver blade sticks
out from the nose.
Replace it.
Replace abnormal parts.
O-rings are worn.
When driving a short nail,
the adjuster set for
insufficient depth.
Check whether or not the
adjuster is set for insufficient
depth.
Use the nailer with the
adjuster set to greater depth.
(Decrease the pressure.)
* The driver blade is worn.
Air pressure is low.
The wood being nailed is
excessively hard.
* The driver blade is worn.
Check whether or not the
sliding face is abnormal and
oil has depleted.
The sliding face of the head
valve is abnormal (seized,
damaged, and/or oil has
depleted).
The cylinder plate or the
O-ring is abnormal
(dislocated, deformed
and/or broken).
Disassemble the cylinder
plate section and check for
abnormality.
Replace the abnormal parts.
Replace the abnormal parts.
Apply grease.

--- 17 ---
Fault Cause
(
The mark * refers to main causes. )Inspection method Remedy
(4)
Nail
jamming
< Nail >
*Nails not approved by
Hitachi are used.
* Abnormal nails are mixed.
*The collation sheet is
abnormal (deformed and/or
broken). (Sheet collation
nails)
Nails fall off.
(Sheet collation nails)
Nails are missing from the
sheet. (Sheet collation
nails)
Abnormality in wire collation
nails (Breakage, wrong
welding, deformation and/or
wrong welding position)
(Wire collation nails)
*Wire collated nails are
deformed.
(Deformation in collation
angle, collation pitch, etc.)
* The diameter of nail head is
too small.
(Wire collation nails whose
head diameter is 4.3 mm
(0.17") or less are liable to
cause jamming)
Check whether or not nails
approved by Hitachi are used.
Check nails referring to the
following figures.
Use the nails approved by
Hitachi.
Remove abnormal nalis and
refill the nailer with normal
nails.
6 mm
(0.24")
(Wire collation nails)
L1D
16
L2
Dimension L219.2
(0.76")
24
(0.94")
Dimension D 4.6 --- 4.7
(0.18" --- 0.19")
4.8
(0.19")
Dimension L17.6
(0.30")
12
(0.47")
Unit : mm
(Sheet collation nails)

--- 18 ---
Check whether or not when
injecting air or actually
injecting nails, the driver blade
is completely returned.
Open the nail guide to check
the position of the feeder
claw.
Check whether or not the
chuck of the feeder holds a
nail, and the first nail is
positioned in the injection
port.
(Check that the second claw
chucks the nail shaft and
feeds it.)
Disassemble the control valve
section to check the O-rings
of plunger (A) and valve
piston (B).
Check for the abnormality
(wear, damage and/or
deformation) in each part.
Check where the single shot/
continuous shot change knob
is positioned.
* The O-ring of plunger (A)
is worn.
* The O-ring of valve piston
(B) is worn.
The sliding face of plunger
(A) of valve piston (B) is
abnormal (seized and/or
deformed).
Plunger (A), trigger (A) and
pushing lever (B) are
abnormal (worn and/or
deformed).
The single shot/continuous
shot switch lever is
positioned incorrectly.
Replace abnormal parts.
Nose…Remove the foreign
matter in the feed piston
chamber.
< Body: Nail feeding is
incomplete. >
The feeder is worn, and the
sliding section is abnormal.
The nail guide face of the
nose and the sliding
section of the feeder are
abnormal (deformed,
warped and/or damaged).
The nail guide face of the
nail guide is worn.
The driver blade head is
worn.
The feed spring and the
feeder spring are abnormal
(damaged, fatigued and/or
damaged).
* The feed piston chamber
contains foreign matter
such as piston bumper
pieces.
Fault Cause
(
The mark * refers to main causes. )Inspection method Remedy
(4)
Nail
jamming
(Continued)
Adjust the air pressure in a
range of 4.9 --- 8.3 bar (5 --- 8.5
kgf/cm2, 70 --- 120 psi).
Replace the abnormal parts.
Set the single shot/continous
shot change knob to a correct
position.
< The driver blade is not
completely returned. >
Refer to Item 1.
< Output section: Piston,
driver blade, etc.>
< Output section: Piston,
driver blade, etc. >
(5)
Single
shot is
impossible.
Air pressure is too high. When nails are driven at a
high pressure and speed,
nails can cause jamming.
Check pressure and driving
speed.
< Body: Abnormality in nail guide section > Refer to Item 1 < Nail guide section >