Nitto Kohki L-25B User manual

INSTRUCTION
MANUAL
 Please read this manual carefully before you attempt to use your tool so that you may use it
properly and safely.
 Please keep the manual handy - so you can use it whenever necessary.
• Due to continuous product development/improvement the specifications and configurations in this
document are subject to change without prior notice.
TQ12790-5 07/2019
<Specifications>
Model L-25B L-35C AL-55A
Maximum Operating Pressure MPa 0.6
Air Consumpion (No Load) m3/min 0.4 0.35 0.17
Rated Speed (No Load) min-1 27000 35500 56500
Size of Collet Chuck mm 6 6 3
Mass (Weight) kg 0.6 0.45 0.27
Sound Pressure Level *1dB(A) 76 76 71
Sound Power Level *1dB(A) 87 87 82
Vibration Level [Uncertainty K] *2m/s27.2 [4.6] 3.1 [0.8] 0.8 [0.6]
Thread Size of Air Inlet Rc1/4 Rc1/4 G1/4
*1 Based on the ISO15744 measurement standard.
*2 Based on the 3 axes combined value measurement standard of the
ISO28927-12 of the hand-tool frequency correction vibration acceleration
effective value.
Professional Tool Pneumatic Die Grinder
Model: L-25B, L-35C, AL-55A
Manufactured by:
NITTO KOHKI CO., LTD. 9-4, Nakaikegami 2-chome, Ohta-ku, Tokyo, 146-8555, Japan
Tel : [phone] Fax : [phone]

EN
Instructions
Thank you very much for your purchase of this NITTO KOHKI product.
Before using your tool, please read this manual carefully so that you may use it properly to get the most out of it.
Please keep the manual handy - so you can use it whenever necessary.
The following Safety notations are used throughout the manual to highlight safety precautions for the user and for the tool.
WARNING: Indicates a potentially hazardous situation which, if not avoided by following the
instructions given, could result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation which, if not avoided by following the
instructions given, could result in injury or material damage.
* Please note, however, that failure to observe safety precautions under the “ CAUTION” category could result in
a serious occurrence depending on the situation.
Please observe all safety precautions in the manual.
CAUTION:Important precautions for tool setup, operation and maintenance.
About pictograms
WARNING:It might be dangerous to operate the tool if the instructions supplied are not followed.
Using this tool improperly could result in serious injury. Read the instruction manual before using.
Contents
Precautions on Use
(Make sure to follow the instructions given) .........1
1 Application.......................................................9
2 Checking Inside the Package..........................9
3 Part Names................................................... 11
4 Air Supply......................................................12
5 Preparation....................................................13
Attachments
Mounting and Removing Mounted Wheels and
Rotary Burrs
6 How to Operate the Tool ...............................16
Start and Stop
Adjust Valve
7 Thread Size of Hose Fitting...........................17
8 Storage..........................................................17
9 Optional Parts ...............................................18
10 Ordering Service Parts..................................18
California Proposition 65
WARNING
Some dust created by power sanding, sawing, grinding, drilling, and other construction activities contains chemicals
known [to the State of California] to cause cancer birth defects or other reproductive harm.
Some examples of these chemicals are:
 Lead from lead-based paints,
 Crystalline silica from bricks and cement and other masonry products, and
 Arsenic and chromium from chemically-treated lumber.
Your risk from these exposures varies, depending on how often you do this type of work. To reduce your exposure
to these chemicals: work in a well ventilated area, and work with approved safety equipment, such as those dust
masks that are specially designed to filter out microscopic particles.

1
EN
Precautions on Use (Make sure to follow the instructions given)
Before using your tool, to avoid personal injury always take the basic precautions explained in later sections.
General Power Tool Safety Warnings
Personal safety
WARNING
 Dress properly.
Do not wear loose clothing or jewelry. There is a
danger of being caught in moving parts. Wear a
pair of non-slip shoes. If your hair is long, wear a
protective hair covering to contain your hair.
 Always wear eye protection.
Corrective glasses are not considered eye
protection. Always wear appropriate eye
protection.
 Wear a dust mask.
When dust is generated in the workplace, wear a
dust mask.
 Use a dust collector or dust collection equipment
correctly.
If a dust collector or dust collection equipment are
being used, check that these are connected and
used properly. Use of a dust collector can reduce
risk caused by dust.
 When loud noise is generated in the workplace,
wear a hearing protection.
 Do not overreach.
Keep proper footing and balance at all times.
 Be on your guard when working.
Do not use the tool when you are tired.
When you use the tool, be sure about the handling method, how to work, and pay sufficient attention to the
surrounding environment.
 Never touch the tip of moving parts when the tool is running.
Also, do not direct the tip of moving parts toward people or animals.
 Be aware of tool vibration and recoil. Some tools can cause a considerable amount of vibration.
Depending on how the product is operated, the type of tool setting, and the length of operation, it could place
a tremendous burden on your hands, arms and body.
The tool could cause a vibration injury or tendonitis. Avoid long-term use and take appropriate breaks.
Consult a doctor if you experience any discomfort or pain while operating the tool.
Protective hair
covering
Dust mask
Work clothing
Safety shoes
Protective
goggles
Earplugs

2
EN
About Work Area
WARNING
 Do not use the tool at home.
This is a professional tool (industrial or work tool for business). Do not bring the tool home and use it there.
 Keep the work area clean.
Working in a messy work area or work table could cause an accident.
 Be cautious about the work area.
Do not expose the tool to rain.
Do not use the tool in a damp or wet place.
Keep the work area well lit.
 Do not operate the tool in an explosive atmosphere, such as in the
presence of flammable liquids (thinner, lacquer, gasoline, etc.) or
gas.
 Do not let children come close to the work area.
Keep children and bystanders away while operating tool.
 Some tools generate loud noise.
Check that the noise regulations of each area are complied with.
 When work has to be done in high locations, make sure there is
nobody underneath the work area.
If the tool or material is dropped, it could cause an accident or
injury.
 Before starting operation, make sure that there is no conduit, water
pipe or gas pipe by your work area.
If a tool touches a buried object, it could cause electrical shock or leakage, which could cause an accident.
Before starting to work
WARNING
 Perform inspection before using the tool.
Before using the tool, check for loose screws on the tool and for damage on the protective cover or other parts,
and make sure that the tool operates normally and demonstrates prescribed functions.
Check the position adjustment and tightening status of moving parts, parts damage, attachment status, and all
other locations for issues that could affect operation.
For parts replacement and repair, follow the instructions indicated in the instruction manual.
If there are no instructions in the instruction manual, contact the retailer where you purchased the tool or the
nearest NITTO service member store.
Do not use the power tool if the switch does not turn it ON and OFF.
 Make sure to properly attach the tip tool.
If the tip tool is not attached properly, there is a risk of jumping out or damage, which could result in injury.
 After adjustment, be sure to remove tools such as spanners, wrenches, etc.
 Use appropriate tools.
Do not force small tools to do the job of a heavy duty tool. Do not use tools for purposes not intended.
 Do not use tools in an unreasonable manner.
When the specifications are followed, tools can be used efficiently and safely.
 Secure workpieces.
Where possible use clamps or a vise to hold the work. It is safe to hold the workpieces by hand and both hands
can be used for operation.
Precautions on Use

3
EN
Handling tools
WARNING
 Storing the tool
When the tool is not used, store the tool in a dry location. Also, store the tool out of the reach of children.
For some tools, the storage temperature and humidity are specified. Store the tool in an appropriate location.
 Be cautious about how the tool is carried.
Do not carry the tool with your hand touching the operation switch.
 Do not leave the tool while the tool is still running.
Do not leave the work area until you turn off the operating switch, remove the power source and the tool
completely stops.
 Do not allow the following chemicals to come into contact with the tool, as parts could deteriorate.
Acetone, benzine, thinner, ketone, ether, trichloroethylene and other similar chemicals
Maintenance and Inspection
WARNING
 Do not disassemble or alter the tool.
Using the tool after disassembling or remodeling it could cause an accident or injury.
 Inspect tip tools and accessories.
Always inspect tip tools and accessories for damage or deterioration before attaching them to the tool.
If damage or deterioration is found, request repair from the retailer where you purchased the tool or the nearest
NITTO service member store.
 Inspect for damaged sections.
Sufficiently check for damage on accessories or other parts, that the tool operates normally, and that work can be
performed appropriately.
If there are accessories or parts that have been damaged or could hinder work, request repair from the retailer
where you purchased the tool or the nearest NITTO service member store.
 Request repair from a dedicated store.
For repair or replacement of parts, request service from the retailer where you purchased the tool or the nearest
NITTO service member store.
Repair requires special knowledge and skills. If repair is performed at a place other than a specialty store, the
tool may not demonstrate its full performance or it could lead to an accident or injury.
Request repair with the failed status kept intact. When requesting a repair, do not throw away damaged parts. It
could be important information for investigating the failure cause so do not change the status.
 Use genuine parts.
If inappropriate parts are used, it could cause accident or injury.
 Genuine parts are listed in the instruction manual or brochure. Inquire at the retailer where you purchased the
tool or the nearest NITTO service member store.
 Do not remove the labels or plates on the tools.
If labels or plates are broken or peeling, for a replacement label or plate contact the retailer where you purchased
the tool or the nearest NITTO service member store.

4
EN
General Pneumatic Tool Safety Warnings
WARNING
 Use the tool with proper air pressure.
If the air pressure is high, the rotation speed and reciprocation frequency become faster, causing damage such
as damage or accelerated wear. Also, unexpected accidents could occur.
 Connect the tool to air piping.
In some factories, other than air piping, there may be other piping such as oxygen, nitrogen, gas, etc. Before
connecting to piping, make sure it is the correct piping.
 Do not start the tool carelessly.
Turn off the operation switch, then attach the Connecting Hose to the tool.
 When attaching, removing, and maintaining accessories, make sure to detach the Connecting Hose from the
tool.
 Be cautious about exhaust.
Pneumatic tool exhaust contains oil and drainage, etc. Be careful about the exhaust direction so that the exhaust
does not directly hit people nearby.
 Do not allow sources of electricity to touch the tool.
The pneumatic tool is not insulated against contact by electric sources. Because there is a risk of electric shock,
do not allow sources of electricity to touch the tool.
CAUTION
 Handle the tool with care.
Rough handling could cause accidents or malfunctions. Do not exert an impact on the tool by throwing or
dropping it.
 Handle the Connecting Hose with care.
Do not carry the tool by holding the Connecting Hose, and do not pull the Connecting Hose to remove it.
Safety Warnings for PNEUMATIC DIE GRINDER
The following warnings are those required to be displayed as instructed by ISO11148-9.
General Safety Rules
WARNING
 For multiple hazards, read and understand this instruction manual before installing, operating, repairing,
maintaining, changing accessories on, or working near this tool. Failure to do so can result in serious bodily
injury.
 Only qualified and trained operators should install, adjust or use this tool.
 Do not modify this tool. Modifications can reduce the effectiveness of safety measures and increase the risks
to the operator.
 Do not discard this instruction manual; hand it to the operator.
 Do not use this tool if the tool has been damaged.
 This tool shall be inspected periodically to verify the ratings and markings. When a label/nameplate is damaged,
worn or missing, contact the retailer where you purchased the tool or the nearest NITTO KOHKI's overseas
affiliates/offices (see the back cover of this manual) directly for a replacement.

5
EN
Projectile Hazards
WARNING
 Be aware that failure of the workpiece or accessories, or even of the inserted tool itself can generate high-
velocity projectiles.
 Always wear impact-resistant eye protection while operating this tool. The grade of protection required should
be assessed for each operation.
 Ensure that the workpiece is securely fixed.
 Check regularly that the speed of this tool is not higher than the speed marked on it. These speed checks shall
be carried out without the abrasive product mounted and in accordance with the instructions given by the
manufacturer.
 Ensure that sparks and debris resulting from use do not create a hazard.
 Disconnect this tool from the energy supply before changing the abrasive product and servicing.
 The risks to others should also be assessed at this time.
Entanglement Hazards
WARNING
 Choking, scalping and/or lacerations can occur if loose clothing, personal jewelry, neckwear, hair or gloves are
not kept away from the tool and its accessories.
Operating Hazards
WARNING
 Avoid contact with the rotating spindle and mounted wheel to prevent cutting of hands and other body parts.
 Use of this tool can expose the operator's hands to hazards, including cuts, abrasions and burns. Wear suitable
gloves to protect hands.
 Operators and maintenance personnel shall be physically able to handle the bulk, weight and power of the tool.
 Hold the tool correctly; be ready to counteract normal or sudden movements and have both hands available.
 Maintain a balanced body position and secure footing.
 Release the start-and-stop device if the energy supply is interrupted.
 Use only lubricants recommended by the manufacturer.
 Personal protective safety glasses shall be used; suitable gloves and protective clothing are recommended.
 The rotary file shall not be operated at a speed exceeding the rated speed.
 For overhead work, wear a safety helmet.
 Be aware that the rotary inserted tool may continue to rotate for a while even after the start-and-stop device has
been released.
 Explosion or fire can occur depending on the type of material and the working condition.
Repetitive Motion Hazards
WARNING
 When using this tool to perform work-related activities, the operator may experience discomfort in the hands,
arms, shoulders, neck or other parts of the body.
 While using this tool, the operator should work in a comfortable posture while maintaining secure footing and
avoiding awkward or off-balance postures. The operator should change posture during extended tasks; this
can help avoid discomfort and fatigue.
 If the operator experiences symptoms such as persistent or recurring discomfort, pain, throbbing, aching,
tingling, numbness, burning sensations or stiffness, these warning signs should not be ignored. The operator
should tell their employer and consult a qualified health professional.

6
EN
Accessory Hazards
WARNING
 Disconnect the tool from the energy supply before fitting or changing the inserted tool or accessory.
 Use only accessories and consumables that are the sizes and types recommended by the manufacturer of this
tool; do not use accessories or consumables of other types or sizes.
 Avoid direct contact with the inserted tool during and after use, as it can be hot or sharp.
 Check that the maximum operating speed of the inserted tool is equal or exceeds the rated speed marked on
the tool.
 Never mount a grinding wheel, cut-off wheel or router cutter on a die grinder. A grinding wheel that bursts can
cause very serious injury or death.
 Do not use mounted wheels that are chipped or cracked, or that could have been dropped.
 Use only permitted inserted tools of the correct shaft diameter.
 Pay attention to the fact that the permitted speed of the mounted point has to be lowered due to the increase
of the length of the shaft between the end of the collet and the mounted point (overhang). Make sure that the
minimum gripping length of 10 mm is observed (see the recommendations of the manufacturer of mounted
points).
 Be aware of the risk of mismatching the diameter of the mounted point’s shaft and the diameter of the collet.
Workplace Hazards
WARNING
 Slips, trips and falls are major causes of workplace injury. Be aware of slippery surfaces caused by the use of
the tool and also of trip hazards caused by the air line or hydraulic hose.
 Proceed with care in unfamiliar surroundings. There can be hidden hazards, such as electricity or other utility
lines.
 This tool is not intended for use in potentially explosive atmospheres and is not insulated against contact with
electric power.
 Ensure that there are no electrical cables, gas pipes, etc., which can cause a hazard if damaged by the use of
the tool.
Dust and Fume Hazards
WARNING
 Dust and fumes generated when using this tool can cause ill health (for example cancer, birth defects, asthma
and/or dermatitis); risk assessment and implementation of appropriate controls for these hazards are essential.
 Risk assessment should include risks such as the dust created by the use of the tool and the potential for
disturbing existing dust.
 Operate and maintain this tool as recommended in these instructions to minimize dust or fume emissions.
 Direct the exhaust so as to minimize disturbance of dust in a dust-filled environment.
 Where dust or fumes are created, the priority shall be to control them at the point of emission.
 All integral features or accessories for the collection, extraction or suppression of airborne dust or fumes
should be correctly used and maintained in accordance with the manufacturer's instructions.
 Select, maintain and replace the consumable or inserted tool as recommended in the instruction handbook to
prevent an unnecessary increase in dust or fumes.
 Use respiratory protection in accordance with the employer's instructions and as required by occupational
health and safety regulations.
 Working with certain materials creates emissions of dust and fumes, causing a potentially explosive
environment.

7
EN
Noise Hazards
WARNING
 Exposure to high noise levels can cause permanent, disabling hearing loss and other problems, such as
tinnitus (ringing, buzzing, whistling or humming in the ears). Therefore, risk assessment and implementation of
appropriate controls for these hazards are essential.
 Appropriate controls to reduce the risk can include actions such as damping materials to prevent workpieces
from “ringing”.
 Use hearing protection in accordance with the employer's instructions and as required by occupational health
and safety regulations.
 Operate and maintain this tool as recommended in the instruction handbook to prevent an unnecessary
increase in the noise level.
 Select, maintain and replace the consumable or inserted tool as recommended in the instruction handbook to
prevent an unnecessary increase in noise.
 If this tool has a silencer, always ensure it is in place and in good working order when the tool is being
operated.
 The noise-emission value in this manual is measured in accordance with ISO standards. Since the real value
may change depending on the work condition, please use this tool with measurements in the actual condition.
Please don't operate beyond the time set by the region where the tool is used.
Vibration Hazards
WARNING
 Exposure to vibration can cause disabling damage to the nerves and blood supply of the hands and arms.
 Wear warm clothing when working in cold conditions and keep your hands warm and dry.
 If you experience numbness, tingling, pain or whitening of the skin in your fingers or hands, stop using this
tool, tell your employer and consult a physician.
 Operate and maintain this tool as recommended in the instruction handbook to prevent an unnecessary
increase in vibration levels.
 Select, maintain and replace the consumable or inserted tool as recommended in the instructions handbook to
prevent an unnecessary increase in vibration levels.
 Support the mass of the tool in a stand, tensioner or balancer, if possible.
 Hold the tool with a light but safe grip, taking account of the required hand reaction forces, because the risk
from vibration is generally greater when the grip force is higher.
 An improperly mounted or damaged inserted tool can cause excessive vibration levels.
 The vibration-emission value in this manual is measured in accordance with ISO standards. Since the real value
may change depending on the work condition, please use this tool with measurements in the actual condition.
Please don't operate beyond the time set by the region where the tool is used.
Additional Safety Instructions
WARNING
 Air under pressure can cause severe injury:
 ―always shut off air supply, drain hose of air pressure and disconnect tool from air supply when not in use,
before changing accessories or when making repairs;
 ―never direct air at yourself or anyone else.
 Whipping hoses can cause severe injury. Always check for damaged or loose hoses and fittings.
 Whenever universal twist couplings (claw couplings) are used, lock pins shall be installed and whip check
safety cables shall be used to safeguard against possible hose-to-tool or hose-to-hose connection failure.
 Do not exceed the maximum air pressure stated on the tool.
 Never carry an air tool by the hose.
 When a tool is taken permanently out of service, it is advised that the tool be disassembled and degreased, and
parts be separated by material and recycled locally in the appropriate manner.

8
EN
Product Specific Safety Rules
The Word "attachment" in the sentences below refers to mounted wheels and rotary burrs.
WARNING
 Do not use an attachment with rated revolution speed (the number of revolutions marked on the package) less
than the actual revolution speed of the Die Grinder.
 Inspect attachment for chips or cracks prior to mounting.
Do not use an attachment that is chipped or cracked or otherwise damaged. Do not use an attachment that has
been soaked in water or any other liquid.
 Make certain the diameter of the attachment mandrel suits the chuck.
Fasten the attachment securely. Use a genuine chuck sleeve.
 After mounting a new attachment, hold the Die Grinder under a steel workbench or inside a casting and run it
for at least one minute.
Make certain no one is within over the rotating surface. If the attachment is defective, improperly mounted or the
wrong size and speed, this is the time it will usually fail.
 Air pressure at the Die Grinder inlet with the Die Grinder running must not exceed 0.6 MPa (6 kgf/cm2, 85 psig, 6
bar)
 When starting a cold Mounted Wheel, apply it to the work slowly until the Mounted Wheel gradually warms up.
Make smooth contact with the work and avoid any bumping action or excessive pressure.
 After a Die Grinder repaired and is issued for use, check the free speed with no attachment mounted using a
tachometer to make certain its actual speed at 0.6 MPa (6 kgf/cm2) does not exceed rated speed stamped or
printed on the name plate.
Die Grinders in use on the job must be similarly checked at least once each shift, When checking, the Adjust
Valve of the tool should be set for maximum speed position.
 Wear protective glasses and a dustproof mask.
Operation generates chips and dust particles, etc. which may cause eye and/or respiratory injury: Always use
PPE (Personal Protective Equipment) for eye and respiratory protection.
 Do not put any inflammable liquid or use the grinding/sanding tool in a potentially explosive atmosphere as
there is a possibility of sparks when grinding which could cause a fire/explosion.
 When you replace or adjust the cutting tool or parts, be sure to detach the tool from the air hose.

9
EN
1 Application
This is handheld Pneumatic die grinder for grinding workpieces using a mounted wheel or a rotary burr.
2 Checking Inside the Package
When you open the package box, check the contents of the package and also check for any damage that may have
occurred during transportation.
If an abnormality is found, request service from the retailer where you purchased the tool or the nearest NITTO service
member store.
L-25B
①
①
②
②
③
③
④
④
⑤ ⑥
Package Contents Qty Check
①L-25B Main Unit 1
②Single Ended Spanner 14 1
③Chuck Pin 1
④Mounted Wheel No.2 1
⑤Mounted Wheel No.3 1
Package Contents Qty Check
⑥Bushing R1/4×NPT1/4 1
⑦Instruction Manual (This
Document) 1
⑧Declaration of Conformity 1
⑨Caution for Use 1
Package Contents Qty Check
①L-35C Main Unit 1
②Single Ended Spanner 14 2
③Mounted Wheel
13×13×6×38 1
④Bushing R1/4×NPT1/4 1
Package Contents Qty Check
⑤Instruction Manual (This
Document) 1
⑥Declaration of Conformity 1
⑦Caution for Use 1
L-35C

10
EN
Package Contents Qty Check
①AL-55A Main Unit 1
②Spanner 7×9 1
③Lock Wrench 1
④Mounted Wheel 5×13×3 1
⑤Bushing R1/4×NPT1/4 1
Package Contents Qty Check
⑥Instruction Manual (This
Document) 1
⑦Declaration of Conformity 1
⑧Caution for Use 1
AL-55A
②③
①
④⑤

11
EN
3 Part Names
L-25B
①Mounted Wheel
② Chuck nut
③ Front Cover
④ Housing
⑤ Valve Ring
⑥ Air Hose
⑦ Socket
①Mounted Wheel
② Chuck nut
③ Front Cover
④ Housing
⑤ Throttle Lever
⑥ Lock Lever
⑦ Air Hose
⑧ Hose Nipple
①Mounted Wheel
② Chuck Nut
③ Lock Ring
④ Housing
⑤ Lock Lever
⑥ Throttle Lever
⑦ Air Hose
⑧ Hose Nipple
②
②
③
③
④
④
①
①
⑤
⑤
⑥
⑥
⑦
⑦
⑧
⑧
L-35C
AL-55A
②③
④
①
⑤
⑥
⑦

12
EN
4 Air Supply
CAUTION
 Remove drainage before stating work.
When drainage enters the tool, the vicinity of the exhaust port freezes, which could cause a loss of power.
①
②
③
④
⑤
⑥
⑦
⑧
①Compressor
②Air Filter
③Air Regulator
④Lubricator
⑤Connecting Hose
⑥Machine Oil
⑦Cupla
⑧Tool
Air pressure used
Use the tool with air pressure at 0.6 MPa. If the pressure is too low, the tool cannot demonstrate the required
performance. If it is too high, it could damage parts of the tool. Use an Air Regulator (③) to adjust the pressure to the
appropriate level.
Air line
Use a Connecting Hose (⑤) with an internal diameter of 9.5 mm (3/8”) between the Compressor (①) and the tool (⑧).
Compressed air exits the Compressor and cools and moisture condenses. Some moisture could condense inside the
Connecting Hose and get inside the tool, causing a malfunction. Install the Air Filter (②) and Lubricator (④) between
the Compressor and the tool.
Machine oil
Install a Lubricator between the Compressor and the tool, and be sure to use machine oil (ISO VG-10).
Failure to do so could cause damage to the tool. Also, if lubricating oil with high viscosity is used, it could cause
performance degradation.
Refueling
Each day before starting work detach the Connecting Hose and refill a few drops of machine oil (ISO VG-10) (⑥) from
the Coupler (⑦) to the tool.
After refueling, connect the Connecting Hose and perform idle operation for a few seconds to allow the oil to blend in
the entire tool.

13
EN
5 Preparation
WARNING
 Do not use any attachment for which the operating speed is lower than the actual free speed of the grinder.
 The attachment mandrel shall be inserted to the full depth of the gripping jaws of the grinder chuck.
Attachments
Selecting Attachments
The maximum speed of an attachment is determined by the factors listed below. Use attachments which have a
strength exceeding the speed of this tool.
(1) Shape and size of the attachment
(2) Size of the mandrel
(3) Overhang of the mandrel
(4) Wheel specification
Mounted Wheel Attachment
WARNING
 Be sure to dress the grinding face of the Mounted Wheel before using it.
 Refer to the table below when selecting Mounted Wheels. When an unmarked Mounted Wheel is to be used, refer
to the manufacturer of the wheel and select one which is safe.
 For 6.0 mm or 3.0 mm mandrels with 13 mm max overhang.
(mm)
L-25B D max=19 L max=25
d=6.0
D max=16
L max=32
d=6.0
D max=16
d=6.0
L-35C D max=16 L max=19
d=6.0
D max=13
L max=19
d=6.0
D max=10
d=6.0
AL-55A D max=6 L max=10
d=3.0
D max=5
L max=13
d=3.0
D=6
d=3.0

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Rotary Burr Attachment
 Squeeze the Rotary Burr lightly against the face to be ground and feed the Rotary Burr in the right-to-left direction.
 Using a double-cut Rotary Burr is recommended.
 Insert the Rotary Burr as deepest as possible and fastened.
 For L-25B, L-35C
Use the blade section not more than 10 mm in diameter.
 For AL-55A
Use the blade section not more than 6.4 mm in diameter and 13 mm or less in length and the shaft 30 mm or less in
length.
Mounting and Removing Mounted Wheels and Rotary Burrs
WARNING
 Be sure to turn off the air supply and disconnect the air hose.
For L-25B
 Mounting
After inserting the Chuck Pin (②) in the Lock Ring, insert the mandrel (④) of the Mounted Wheel (⑤) in the Chuck
and secure it by turning the Chuck Nut (①) with the Spanner 14 (③) in a clockwise direction. The Chuck Pin (②)
serves to prevent rotation at this time.
 Removal
Turn the Chuck Nut (①) in a counterclockwise direction with the Spanner 14 (③) and withdraw the mandrel(④)
from the chuck.
②
③
④①
⑤
①Chuck Nut
②Chuck Pin
③Spanner 14
④Mandrel
⑤Mounted Wheel or Rotary Burr
Loosen
Tighten

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For L-35C
 Mounting
Hold the body of the chuck with a Spanner 14 (③) and insert the Rotary Burr (⑤) mandrel (④). Secure the Rotary
Burr (⑤) by turning the Chuck Nut (①) with another Spanner 14 (③) in a clockwise direction.
 Removal
Turn the Chuck Nut (①) in a counterclockwise direction with the Spanner 14 (③) and withdraw the mandrel (④)
from the chuck.
②
③
④
①
⑤
①Chuck Nut
②Chuck Body
③Spanner 14
④Mandrel
⑤Mounted Wheel or Rotary Burr
①Chuck Nut
②Front Cover
③Lock Wrench
④Mounted Wheel or Rotary Burr
⑤Mandrel
⑥Spanner 7×9
For AL-55A
 Mounting
Align the holes of the Chuck Nut (①) and the Front Cover (②) and Insert the lock wrench (③). Insert the Mandrel
(⑤) into the chuck and turn the Chuck Nut (①) clockwise with a Spanner 7×9 (⑥) to fix the Mandrel (⑤).
 Removal
Turn the Chuck Nut (①) in a counterclockwise direction with the Spanner 7×9 (⑥) and withdraw the mandrel (⑤)
from the chuck.
②
③
④①
⑥
⑤
Loosen
Loosen
Tighten
Tighten

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6 How to Operate the Tool
WARNING
 Always wear eye protection during operations.
 Start the equipment. Then squeeze the equipment lightly against the workpiece and moveAIR SONIC in the direction of the
arrow, as shown in Fig.
 Strong push against the workpiece will not improve working efficiency. Such strong push may cause damage to the
Mounted Wheel and the Rotary Burr.
Start and Stop
For L-25B, L35C
To start: Release the Lock Lever (①) and grasp the Throttle Lever (②).
To stop : Release the Throttle Lever (②).
For AL-55A
To start: Turn the Valve Ring (①) clockwise and match [▲] to [
■
] on the Housing ( ②).
To stop : Turn the Valve Ring (①) counterclockwise and match [▲] to [●] on the Housing (②).
Feeding direction
Direction of rotation of the rotary burr
Work material
②
ON
ON
OFF OFF
①
①Lock Lever
②Throttle Lever
①Housing
②Valve Ring
②
①Release

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Adjust Valve
WARNING
 Be sure to keep hands clear of moving parts.
For L-25B, L-35C
The desired speed between maximum and
minimum speed is obtainable by turning the
groove of valve in a clockwise or counterclockwise
direction with screwdriver.
 Maximum speed
Position the groove of Adjust Valve (①) horizontal
to main body.
 Minimum speed
Position the groove of Adjust Valve (①) vertical
to main body.
For AL-55A
The motor speed can be adjusted in the range from 0 to the maximum speed by adjusting the opening of the valve.
Adjust the motor speed according to the purpose of use.
7 Thread Size of Hose Fitting
The product comes with a metal fitting with R (metric) thread. Connect the Bushing R thread × NPT thread included as
standard accessories, if you would like to have American NPT thread instead.
8 Storage
CAUTION
 When tool is not used, store it out of reach of children.
Avoid storing the tool in a location subject to high humidity. If the tool is left as it is used, residual moisture on the
inside can cause rusting. Before storing, and after operation, oil the tool at the air inlet with machine oil ISO VG-10 and
run it for a short time.
①Adjust Valve
Maximum
Minimum
①

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9 Optional Parts
L-25B
Part No. Description Qty
TA9A277 Mounted Wheel No.1 5 pcs
TA9A278 Mounted Wheel No.2 5 pcs
TA9A279 Mounted Wheel No.3 5 pcs
TA9A280 Mounted Wheel No.4 5 pcs
TA9A281 Mounted Wheel No.5 5 pcs
TA9A282 Mounted Wheel No.6 5 pcs
TA9A283 Mounted Wheel No.7 5 pcs
TA9A284 Mounted Wheel No.8 5 pcs
L-35C
Part No. Description Qty
TP10594 Rotary Burr No.1 1
TP10595 Rotary Burr No.2 1
TP10596 Rotary Burr No.3 1
TP10597 Rotary Burr No.4 1
TP10598 Rotary Burr No.5 1
TP10599 Rotary Burr No.6 1
TP10600 Rotary Burr No.7 1
TP10601 Rotary Burr No.8 1
AL-55A
Part No. Description Qty
TB00137 Mounted Wheel 5×13×3 10 pcs
10 Ordering Service Parts
For further operational and handling information or for replacement of parts and components, contact the
company from whom you purchased the tool or an authorized dealer.
In ordering parts and components give each part number, part name and quantity required. Use only NITTO
genuine parts.