Hitachi NR 90AD (S) Manual

TECHNICAL DATA
AND
SERVICE MANUAL
STRIP NAILER
NR 90AD
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No. E016 Jun. 2004
N
MODEL
NR 90AD
Hitachi 
Power Tools

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
PPaslode F-350S
QSENCO FramePro 701XP

CONTENTS
Page
1. PRODUCT NAME............................................................................................................................. 1
2. MARKETING OBJECTIVE ............................................................................................................... 1
3. APPLICATIONS................................................................................................................................ 1
4. SELLING POINTS ............................................................................................................................ 1
5. SPECIFICATIONS ............................................................................................................................ 2
5-1. Specifications.....................................................................................................................................2
5-2. Explanation of the Nailing Action .......................................................................................................3
5-3. Nail Selection.....................................................................................................................................4
5-4. Nail Driving Force ..............................................................................................................................5
6. COMPARISONS WITH SIMILAR PRODUCTS ................................................................................ 6
7. PRECAUTIONS IN SALES PROMOTION ....................................................................................... 7
7-1. Handling Instructions .........................................................................................................................7
7-2. Warning Label....................................................................................................................................7
7-3. Related Laws and Regulations ..........................................................................................................8
8. MECHANISM AND OPERATION PRINCIPLE ................................................................................. 9
8-1. Mechanism ........................................................................................................................................9
8-2. Operation Principle ..........................................................................................................................11
9. TROUBLESHOOTING GUIDE ....................................................................................................... 14
9-1. Troubleshooting and Correction.......................................................................................................14
9-2. Regrinding the Driver Blade.............................................................................................................17
9-3. Possible Causes and Correction of Air Leakage .............................................................................18
10. DISASSEMBLY AND REASSEMBLY .......................................................................................... 20
10-1. General Precautions in Disassembly and Reassembly .................................................................20
10-2. Disassembly and Reassembly of the Output Section....................................................................21
10-3. Disassembly and Reassembly of the Control Valve Section .........................................................24
10-4. Disassembly and Reassembly of the Driving Section ...................................................................27
10-5. Disassembly and Reassembly of the Cap and the Magazine Section ..........................................30
11. INSPECTION AND CONFIRMATION AFTER REASSEMBLY .................................................... 33
12. STANDARD REPAIR TIME (UNIT) SCHEDULES ....................................................................... 34
Assembly Diagram for NR 90AD

--- 1 ---
1. PRODUCT NAME
Hitachi 90 mm (3-1/2") Strip Nailer, Model NR 90AD
2. MARKETING OBJECTIVE
The Model NR 90AD is a framing nailer for clipped head (D-head) nails. This is developed as a next-generation
nailer with an all-new design in order to expand our market share. The main features of the Model NR 90AD are
as follows:
(1) Lightweight (3.2 kg) and good balance
(2) Low height
(3) Rapid driving and quick response mechanism
(4) New aggressive appearance
(5) Selective actuation (single actuation/contact actuation)
(6) Tool-less depth adjustment
(7) Comfortable grip
3. APPLICATIONS
Floor and framing
Truss build-up, window build-up
Subflooring and roof decking
Wall sheathing
Mobile home and modular housing construction
4. SELLING POINTS
With "single actuation/
contact actuation" selector
New aggressive appearance
Low height
Rapid driving and
quick response
Tool-less depth
adjustment
Comfortable grip
Lightweight, only 3.2 kg (7.0 lbs.) and good balance

--- 2 ---
Optional accessories
Nail capacity
3.2 kg (7.0 lbs.)
2.5 ltr/cycle at 7 kgf/cm2(0.088 ft3/cycle at 100 psi) (2.5 ltr/cycle at 6.9 bar)
Corrugated cardboard box
3 pcs./sec.
Driving speed
462 mm x 322 mm x 125 mm
(18-3/16" x 12-11/16" x 4-15/16")
86 nails
Dimensions
(Length x Height x Width)
Nail feed system
3/8 NPT thread
Standard accessories
Weight
Spiral spring
Air consumption
Air inlet
Package dimensions
(Length x Height x Width)
Packaging
587 mm x 398 mm x 136 mm
(23-1/8" x 15-21/32" x 5-11/32")
Safety glasses (Code No. 875769)............................................................ 1
Pneumatic tool lubricant (1 oz oil feeder) (Code No. 877153)
Pneumatic tool lubricant (4 oz oil feeder) (Code No. 874042)
Pneumatic tool lubricant (1 quart can) (Code No. 876212)
Grease (ATTOLUB No. 2) (500 g (1.1 lbs.)) (Code No. 317918)
5. SPECIFICATIONS
5-1. Specifications
Reciprocating piston type
Model
Driving system
NR 90AD
Operating pressure 5 --- 8.5 kgf/cm2 (70 --- 120 psi, 4.9 --- 8.3 bar) (Gauge pressure)

--- 3 ---
5-2. Explanation of the Nailing Action
To meet the requirements of "ANSI SNT-101-2002", the Model NR 90AD is equipped with a nailing operation
switching device at the valve portion as shown in the figures below. Use SINGLE ACTUATION MECHANISM
(SINGLE SEQUENTIALACTUATION MECHANISM) or CONTACT ACTUATION MECHANISM in accordance with
the work to be performed. Each nailing operation is as follows.
SINGLE ACTUATION MECHANISM (SINGLE SEQUENTIALACTUATION MECHANISM):
First, press the pushing lever against the wood; next, pull the trigger to drive the nail. First, pull the trigger;
next, press the pushing lever against the wood to drive the nail. After nailing once, nailing will not be possible
again until the trigger is released and pressed again.
CONTACT ACTUATION MECHANISM:
First, press the pushing lever against the wood; next, pull the trigger to drive the nail. First, pull the trigger;
next, press the pushing lever against the wood to drive the nail. If the trigger is held back, a nail will be driven
each time the pushing lever is pressed against the wood.
Nailing operation switching device
Switching device
(Change knob) Switching device
(Change knob)
SINGLE ACTUATION
MECHANISM
(Switching device:
upward position)
CONTACT ACTUATION
MECHANISM
(Switching device:
downward position)

--- 4 ---
5-3. Nail Selection
The Model NR 90AD utilizes D-head (clipped head) nails collated with paper tape.
Applicable nail dimensions are shown below. Please note that screw-type nails cannot be used with the Model
NR 90AD.
CAUTION: Ensure that nails are as specified in Fig. 1. The Model NR 90AD utilizes D-head (clipped
head) nails collated at an angle of 35 degrees which are the same as the nails utilized by P.
However, some D-head nails made by other makers are collated at a different angle of 26
degrees. Use of such nails will cause clogging of nails and subsequent damage to the
nailer. Also avoid use of misaligned nails or nails collated with a weak paper tape. Do not
use P's 2" Roundrive nail (eccentric full round head nail) with the Model NR 90AD because it
may cause bending of nails. It is recommended to use genuine HITACHI nails to ensure
satisfactory driving quality.
6.8 mm
(0.266")
2.9 mm
(0.113")
50 mm (2")
Minimum
Paper tape collated strip nails D-head (clipped head) nails
Fig. 1 Dimensions of nail
Maximum
7.7 mm
(0.303")
90 mm (3-1/2")
3.8 mm
(0.148")
35˚
Paper tape
3.8 mm x 90 mm nails
(0.148" x 3-1/2")
Max.
4.6 mm
(0.181")
Max.
31.7 mm
(1.248")

--- 5 ---
5-4. Nail Driving Force
Figure 2 shows by type of wood and nail, the nailer output energy provided by the supply pressure and the nailing
energy required for driving the nail flush. Air pressure which exceeds the intersecting point between the nailer
output energy and the nailing energy required for driving the nail allows the nail to be fully driven.
For example, when driving a nail of 3.3 mm dia. by 90 mm length (0.131" x 3-1/2") into nine sheets of 12 mm
plywood (108 mm thick ) with the Model NR 90AD, a pressure of about 6.8 bar (6.9 kgf/cm2, 99 psi) allows the
nailer to drive the nail flush with the wood surface. Apressure beyond this value causes the nail head to be driven
below the wood surface. Fig. 2 should be used as reference data because those values vary depending on the
type, moisture content, and grain of wood.
Fig. 2 Required nailing energy and nailer output energy
NR 90AD
NR 83AA3, P, Q
12 mm (0.47")
plywood x 9
Required nailing energy Nailer output energy

--- 6 ---
6. COMPARISONS WITH SIMILAR PRODUCTS
2.9 mm --- 3.3 mm
(0.113" --- 0.131")
Maker HITACHI
Air consumption at
7 kgf/cm2(100 psi)
Operating pressure
Magazine type
Weight
Dimensions
(L x H x W)
Model
Nail capacity
(3-1/4" x 0.131)
5 --- 8.5 kgf/cm2
(70 --- 120 psi)
462 mm x 322 mm x 125 mm
(18-3/16" x 12-11/16" x 4-15/16")
NR 90AD
2.5 ltr/cycle
(0.08 ft3/cycle)
86
Rear loading (Aluminum)
3.2 kg (7.0 lbs.)
5 --- 8.5 kgf/cm2
(70 --- 120 psi)
460 mm x 360 mm x 108 mm
(18-1/8" x 14-3/16" x 4-1/4")
NR 83AA3
2.1 ltr/cycle
(0.073 ft3/cycle)
86
Rear loading (Aluminum)
3.9 kg (8.7 lbs.)
5.6 --- 8.5 kgf/cm2
(80 --- 120 psi)
488 mm x 333 mm x 130 mm
(19-7/32" x 13-1/8" x 5-1/8")
2.0 ltr/cycle
(0.07 ft3/cycle)
89
Top loading (Aluminum)
3.7 kg (8.2 lbs.)
With wrench
P
Driving depth
adjustment mechanism Tool not required Not provided With wrench
Protection of free-fire Not provided Not provided Provided Direction change of
exhaust air
Handing grip
Applicable
nails
(Clip head) Length
Dia.
Not provided
Rubber
50 mm --- 90 mm
(2" --- 3-1/2")
2.9 mm --- 3.8 mm
(0.113" --- 0.148")
Not provided
Rubber
50 mm --- 83 mm
(2" --- 3-1/4")
Rubber
50 mm --- 90 mm
(2" --- 3-1/2")
2.9 mm --- 3.8 mm
(0.113" --- 0.148")
Tool not required
5 --- 7 kgf/cm2
(70 --- 100 psi)
380 mm x 333 mm x 107 mm
(14-31/32" x 13-1/8" x 4-1/4")
2.6 ltr/cycle
(0.091 ft3/cycle)
64
Rear loading (Aluminum)
3.8 kg (8.4 lbs.)
Tool not required
Q
Provided
Rubber
50 mm --- 90 mm
(2" --- 3-1/2")
2.9 mm --- 3.8 mm
(0.113" --- 0.148")
Not provided
Single actuation/
contact actuation
selector
Provided Not provided Not provided

--- 7 ---
7. PRECAUTIONS IN SALES PROMOTION
In the interest of promoting the safest and most efficient use of the Model NR 90AD 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.
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 pneumatic tool cannot be completely eliminated.
Accordingly, general precautions and suggestions for use of pneumatic tools, and specific precautions and
suggestions for the use of the pneumatic nailer 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 customers during sales promotion.
7-2. Warning Label
Each Model NR 90AD unit is provided with a Warning Label (illustrated below) which lists basic safety precautions
in its use. Carefully ensure that customers fully understand and follow these precautions before using the tool.