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