Central Pneumatic 93727 User manual

SKU 93727 For technical questions, please call 1-800-444-3353 Page 1
1/4” Air Angle Grinder
ASSEMBLY AND OPERATING INSTRUCTIONS
3491 Mission Oaks Blvd., Camarillo, CA 93011
Visit our Web site at http://www.harborfreight.com
Copyright © 2006 by Harbor Freight Tools®. All rights reserved.
No portion of this manual or any artwork contained herein may be reproduced in any shape or form
without the express written consent of Harbor Freight Tools.
For technical questions and replacement parts, please call 1-800-444-3353
Manual Revised 11h
93727
Due to continuing improvements, actual product may differ slightly from the product described herein.

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Specications
Construction: Cast Aluminum Housing with
Machined Steel Components Air Consumption: 90 psi operating pressure 3.25 cfm air consumption
Tool Holder: 1/4” Collet Operating Speed: 16,000 rpm max.
Air Inlet: 1/4” npt Air Inlet Screen: 20 mesh
Overall Dimensions: 6-¼”L x 3”H x 1-½”W Net Weight: 1-¼ lbs.
Save This Manual
You will need the manual for the safety warnings and precautions, assembly instructions, operat-
ing and maintenance procedures, parts list and diagram. Keep your invoice with this manual. Write the
invoice number on the inside of the front cover. Keep the manual and invoice in a safe and dry place for
future reference.
Safety Warnings and Precautions
WARNING: When using tool, basic safety precautions should always be followed to reduce the risk
of personal injury and damage to equipment. Read all instructions before using this tool!
1. Keep work area clean. Cluttered areas invite injuries.
2. Observe work area conditions. Do not use machines or power tools in damp or wet locations.
Don’t expose to rain. Keep work area well lit. Do not use electrically powered tools such as an air
compressor in the presence of ammable gases or liquids.
3. Keep children away. Children must never be allowed in the work area. Do not let them handle
machines, tools, or extension cords.
4. Store idle equipment. When not in use, tools must be stored in a dry location to inhibit rust.
Always lock up tools and keep out of reach of children.
5. Use the right tool for the job. Do not attempt to force a small tool or attachment to do the work of a
larger industrial tool. There are certain applications for which this tool was designed. It will do the job
better and more safely at the rate for which it was intended. Do not modify this tool and do not use
this tool for a purpose for which it was not intended.
6. Dress properly while working. Do not wear loose clothing or jewelry as they can be caught
in moving parts. Protective, electrically non-conductive clothes and non-skid footwear are
recommended when working. Wear restrictive hair covering to contain long hair.
7. Use eye and ear protection. Always wear ANSI approved impact safety goggles. Wear a full
face shield if you are producing metal lings or wood chips. Wear an ANSI approved dust mask or
respirator when working around metal, wood, and chemical dusts and mists.
WARNING! Some dust created by power sanding, sawing, grinding, drilling, and other construction
activities, contain 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 or other masonry products, 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 lter
out microscopic particles. (California Health & Safety Code § 25249.5, et seq.)

SKU 93727 For technical questions, please call 1-800-444-3353 Page 3
8. Do not overreach. Keep proper footing and balance at all times. Do not reach over or across
running machines.
9. Maintain tools with care. Keep tools clean and in good condition for better and safer performance.
Follow instructions for lubricating and changing accessories. Inspect tool ttings and hoses
periodically and, if damaged, have them repaired by an authorized technician. The handles must be
kept clean, dry, and free from oil and grease at all times.
10. Stay alert. Watch what you are doing, and use common sense when operating a power tool.
Do not use a power tool while tired or under the inuence of drugs, alcohol, or medication. A
moment of inattention while operating power tools may result in serious personal injury.
11. Avoid accidental starting. Be sure the Throttle Lever is in the OFF position before attaching
the air pressure hose. Carrying power tools with your nger on the throttle lever invites accidents.
12. Remove adjusting keys or wrenches before turning the power tool on. A wrench or a key that
is left attached to a rotating part of the power tool may result in personal injury.
13. Do not overreach. Keep proper footing and balance at all times. Proper footing and balance
enables better control of the power tool in unexpected situations.
14. Use clamps (not included) or other practical ways to secure and support the work piece to a stable
platform. Holding the work by hand or against your body is unstable and may lead to loss of control.
15. Do not use the power tool if the Power Switch does not turn it on or off. Any tool that cannot be
controlled with the Power Switch is dangerous and must be replaced.
16. Disconnect the air hose from the tool before making any adjustments, changing accessories,
or storing the tool. Such preventive safety measures reduce the risk of starting the tool acciden-
tally.
17. Check for misalignment or binding of moving parts, breakage of parts, and any other
condition that may affect the tool’s operation. If damaged, have the tool serviced before
using. Many accidents are caused by poorly maintained tools.
18. Tool service must be performed only by qualied repair personnel. Service or maintenance
performed by unqualied personnel could result in a risk of injury.
19. When servicing a tool, use only identical replacement parts. Use of unauthorized parts or failure
to follow maintenance instructions may create a risk of electric shock or injury.
20. Maintain labels and nameplates on the tool. These carry important information. If unreadable or
missing, contact Harbor Freight Tools for a replacement.
21. When starting a hand-held power tool, always maintain a rm grip on the tool with both
hands to resist starting torque.
22. Always keep the air pressure hose away from moving parts on the tool.
23. Hold tool by insulated gripping surfaces when performing an operation where the tool may
contact hidden wiring. Contact with a “live” wire will make exposed metal parts of the tool
“live” and shock the operator.
24. Never lay the tool down until the motor has come to a complete stop. The tool may create
unforeseen risk while the motor cycles down.
Warning: The warnings, cautions, and instructions discussed in this instruction manual can-
not cover all possible conditions and situations that may occur. It must be understood by the
operator that common sense and caution are factors which cannot be built into this product,
but must be supplied by the operator.

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Assembly
1. Install the Male Quick Connect Coupler (40) to the Air Inlet (7). First wrap the threaded portion of the
coupler with pipe thread seal tape before threading it into the Air Inlet (7). Tighten securely.
2. Attach a standard quick connector (not included) to your air pressure source hose. Then attach the
air hose to the Quick Connect Coupler (40).
3. Set the air pressure regulator at 90 psi. WARNING: Do not exceed the recommended pressure of 90
psi. Damage to your tool, and possible personal injury may result.
4. Check the air line and its connections for air leaks. Make note of these, and repair them before using this tool.
5. Install an appropriate grinder following instructions on next page. NOTE: Turn off your air
compressor and disconnect the air pressure hose before changing grinders or making any
adjustments to this tool. Severe injury or property damage may otherwise result.
WARNING: This tool is rated at a maximum RPM of 16,000, assuming a maximum
air inlet pressure of 90 PSI. Use only with regulated air not to exceed 90 PSI,
as unregulated air or higher pressure could cause the Grinder to exceed the
maximum intended RPM.
WARNING! All accessories for this tool must be rated for at least 16,000 RPM. Grinding wheels
and other accessories running over their rated speed can y apart and cause injury.
Use only grinding wheels having a 1/4” center mounting axle.
WARNING! Never install a carbide tipped or steel circular saw blade for use in this tool. Never
install a wood carving blade, carving disc with chain saw cutters, or a cutting carving disc on
this tool.
For safest operation, it is recommended that only these accessories be used with this tool:
Abrasive cut-off discs and wheels, ap wheels, wire brushes, wire wheel brushes.
Before each use, inspect the accessory for cracking, over-worn condition, and other damage;
never use a damaged accessory.
NOTE: If you are not using an automatic in-line oiler, add a few drops of pneumatic oil to the Air Inlet
(7) before attaching the air hose. Add a few more drops of oil after every hour of continual use.
NOTE: Performance of this tool may vary depending on variations in local air pressure.
Air Pressure Supply
We recommend that you use both a lter and an in-line oiler in your air supply system as illustrated
in the diagram below. These components are not included with this tool, but are available from Harbor
Freight Tools.
We recommend that you install a quick-release nipple (not included) into the Air Inlet Bushing (7).
Working with air powered tools is easier and more convenient if you install quick release connectors at all
attachment points in your system.
Air Angle
Grinder

SKU 93727 For technical questions, please call 1-800-444-3353 Page 5
Unpacking
Your product includes the Air Angle Grinder, Male Quick
Connect Coupler, and Two Collet Wrenches. When un-
packing, check to make sure that the product is intact
and undamaged.
If any parts are missing or broken, please call Harbor
Freight Tools at the number on the cover of this manual.
Operation
1. Select the appropriate size grinder accessory (not
included) for your needs. The grinder must have an
integral 1/4” shaft to t in the collet.
2. Disconnect the air pressure hose from the tool.
3. Using the smaller Collet Wrench (37) prevent the Collet Holder (25) from turning. Using the large
Collet Wrench (38) turn the Collet Nut (36) counterclockwise to loosen it.
4. Insert the 1/4” shaft of the accessory grinder into the collet.
5. Using the smaller Collet Wrench (37) prevent the Collet Holder (25) from turning, use the large Collet
Wrench (38) turn the Collet Nut (36) clockwise to tighten it. Be sure the grinding wheel is centered in
the Collet (35), and held tight before beginning work.
6. When it is safe to do so, squeeze the Throttle Lever (2) to start the tool. Apply it to the work surface
as needed. When you are done grinding, release the Throttle Lever to stop the tool.
Specic Safety Precautions
1. Always wear safety equipment, including ear protection, and ANSI approved face shield and safety
goggles when using this tool.
2. The grinding wheel will continue to turn for a few seconds after the tool is turned off. Do not set the
tool down until the wheel has stopped turning.
3. Do not start the tool with the grinding wheel in contact with any surface. Start it rst, then apply the
grinding wheel to the work surface.
4. When the tool is in use, keep hands away from the cutting or grinding area.
5. Only use grinding and cutting wheels which are rated for 16,000 rpm or greater.
6. Only use grinding or cutting wheels with a 1/4” shaft designed for 1/4” collet type grinders.
7. Keep the air pressure hose well away from the work area. Always position the pressure hose so it
will not be caught in the work piece, or damaged by the grinding wheel.
8. Inspect the tool and the grinding wheel for safety before attaching the air pressure hose to the tool.
Maintenance Note: Inject a small amount of medium weight oil into the Oil Valve (29) after each
hour of continuous use.

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About Power Grinders and Grinding Wheels
While an extremely useful tool, power grinders can be dangerous if damaged or used improperly.
1. Grinding wheels are made of aggregates of a cutting material (grit) such as Aluminum Oxide, an
epoxy binder and usually a fabric matrix. During manufacture, the grit portion of the wheel is bonded
to steel anges which are bonded to the 1/4” shaft.
2. Grinding wheels come in dimensional sizes, speed ranges and grit sizes.
3. This grinder is designed to accept grinding wheels, with an shaft diameter of 1/4”. Do not use
wheels of any other size.
4. This grinder has a maximum speed of 16,000 rpm. WARNING: Do not use a grinding wheel
which is not rated for at least this speed. Using lower speed rated wheels at higher speed
may cause the grinding wheel to come apart and be ejected from the grinder at high speed,
possibly causing severe personal or property damage.
5. Grinding wheels are identied by the material which makes up the grit, the recommended workpiece
material, and a grit number which indicates the coarseness of the grit. Lower numbers are more
coarse. Coarse grits cut faster, but leave a rough surface. Finer grits (higher grit numbers) cut more
slowly, but leave a more nished surface. Select the grit which is appropriate to the job at hand.
6. During use, grinding wheels may become unevenly worn, cracked or chipped. Wheels which are
damaged in this way will usually cause the grinder to vibrate. WARNING: Damaged grinding
wheels may break apart during use, possibly causing injury. Never use a damaged or
unevenly worn grinding wheel.
7. No abrasive wheel or disc should be used without an appropriate safety guard. No guard is currently
available for this tool as abrasive at wheels or grinding wheels are NOT intended accessories.
Using the Angle Grinder
Before using the Angle Grinder, be sure all work area safety precautions are being observed. Be
sure to wear ANSI approved eye protection.
1. Start the tool, and place it on the workpiece at a 10 to 15° angle.
2. Guide the tool back and forth over the workpiece in a steady motion. Do not press down, but allow
the weight of the tool to do the work.
3. When cutting with the Angle Grinder, only use a cutting wheel with a thin cutting edge. Keep the
cutting wheel straight in the cut to prevent the wheel from being damaged.
CAUTION: This tool is not designed for wet grinding. Do not use water or other lubricants
while grinding or cutting with this tool.
NOTE: Do not cover the exhaust ports while the tool is in use. This will reduce the efciency of the
tool, and may cause damage.
4. Do not use a cutting wheel for rough grinding. Cutting wheels are thin and may break if used for grinding.

SKU 93727 For technical questions, please call 1-800-444-3353 Page 7
Parts List
PLEASE READ THE FOLLOWING CAREFULLY
THE MANUFACTURER AND/OR DISTRIBUTOR HAS PROVIDED THE PARTS DIAGRAM IN THIS MANUAL AS A REFERENCE
TOOL ONLY. NEITHER THE MANUFACTURER NOR DISTRIBUTOR MAKES ANY REPRESENTATION OR WARRANTY OF
ANY KIND TO THE BUYER THAT HE OR SHE IS QUALIFIED TO MAKE ANY REPAIRS TO THE PRODUCT OR THAT HE OR
SHE IS QUALIFIED TO REPLACE ANY PARTS OF THE PRODUCT. IN FACT, THE MANUFACTURER AND/OR DISTRIBUTOR
EXPRESSLY STATES THAT ALL REPAIRS AND PARTS REPLACEMENTS SHOULD BE UNDERTAKEN BY CERTIFIED AND
LICENSED TECHNICIANS AND NOT BY THE BUYER. THE BUYER ASSUMES ALL RISK AND LIABILITY ARISING OUT OF
HIS OR HER REPAIRS TO THE ORIGINAL PRODUCT OR REPLACEMENT PARTS THERETO, OR ARISING OUT OF HIS OR
HER INSTALLATION OF REPLACEMENT PARTS THERETO.
Part Description QTY.
1 Housing 1
2 Throttle Lever 1
3 Throttle Lever 1
4 O-Ring 1
5Mufer Cover 1
6 O-Ring 1
7 Air Inlet 1
8 Sleeve 1
9 Valve Bushing 1
10 Valve Stem 1
11 Valve 1
12 Spring 1
13 O-Ring 1
14 Valve Plug 1
15 Bearing 1
16 End Plate 1
17 Pin 2
18 Rotor 1
19 Rotor Blade 4
20 Cylinder 1
Part Description QTY.
21 Bushing 1
22 Front Plate 1
23 Pin 1
24 Bearing 2
25 Collet Holder 1
26 Retainer 1
27 Housing Cap 1
28 Angle Housing 1
29 Oil Valve 1
30 Bearing 1
31 Angled Gear 1
32 Retainer 1
33 Spindle 1
34 Woodruff Key 1
35 Collet 1
36 Collet Nut 1
37 Wrench 1
38 Wrench 1
39 Collet 1
40 Male Quick Connect Coupler 1

SKU 93727 For technical questions, please call 1-800-444-3353 Page 8
Assembly Drawing
NOTE: Some parts are listed and shown for illustration purposes only and are not available individually as
replacement parts.

SKU 93727 For technical questions, please call 1-800-444-3353 Page 9
90 Day Warranty
Harbor Freight Tools Co. makes every effort to assure that its products meet
high quality and durability standards, and warrants to the original purchaser that
this product is free from defects in materials and workmanship for the period
of 90 days from the date of purchase. This warranty does not apply to damage
due directly or indirectly, to misuse, abuse, negligence or accidents, repairs or
alterations outside our facilities, criminal activity, improper installation, normal
wear and tear, or to lack of maintenance. We shall in no event be liable for
death, injuries to persons or property, or for incidental, contingent, special or
consequential damages arising from the use of our product. Some states do
not allow the exclusion or limitation of incidental or consequential damages, so
the above limitation of exclusion may not apply to you. THIS WARRANTY IS
EXPRESSLY IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS.
To take advantage of this warranty, the product or part must be returned to us
with transportation charges prepaid. Proof of purchase date and an explanation
of the complaint must accompany the merchandise. If our inspection veries the
defect, we will either repair or replace the product at our election or we may elect
to refund the purchase price if we cannot readily and quickly provide you with a
replacement. We will return repaired products at our expense, but if we determine
there is no defect, or that the defect resulted from causes not within the scope of
our warranty, then you must bear the cost of returning the product.
This warranty gives you specic legal rights and you may also have other rights
which vary from state to state.