OPERATOR'S MANUAL
4-1/2 in. (115 mm) Angle Grinder
Model AG451 / Double Insulated
SPECIFICATIONS:
Grinding Wheel Capacity
Rating
4-1/2 in. (115 mm)
120 volts, 60Hz, AC only
11,000 RPM
No Load Speed
Amperes
5.5 Amperes
Net Weight
4.6 lbs. (2.1 kg.)
THANK YOU FOR BUYING A RYOBI ANGLE GRINDER.
YournewanglegrinderhasbeenengineeredandmanufacturedtoRyobi'shighstandardfordependability, easeofoperation,
and operator safety. Properly cared for, it will give you years of rugged, trouble-free performance.
CAUTION: Carefully read through this entire operator's manual before using your new angle grinder.
Pay close attention to the Rules for Safe Operation, Warnings, and Cautions. If you use your grinder properly and only for
what it is intended, you will enjoy years of safe, reliable service.
Please fill out and return the Warranty Registration Card so that we can be of future service to you.
Thank you again for buying Ryobi tools.
SAVE THIS MANUAL FOR FUTURE REFERENCE
RULES FOR SAFE OPERATION
The purpose of safety symbols is to attract your attention to possible dangers. The safety symbols, and the
explanations with them, deserve your careful attention and understanding. The safety warnings do not by
themselves eliminate any danger. The instructions or warnings they give are not substitutes for proper
accident prevention measures.
SYMBOL
MEANING
SAFETY ALERT SYMBOL:
Indicates danger, warning, or caution. May be used in conjunction with other symbols or pictographs.
DANGER: Failure to obey a safety warning will result in serious injury to yourself or to others. Always
follow the safety precautions to reduce the risk of fire, electric shock and personal injury.
WARNING:Failuretoobeyasafetywarningcanresultinseriousinjurytoyourselfortoothers.Always
follow the safety precautions to reduce the risk of fire, electric shock and personal injury.
CAUTION: Failure to obey a safety warning may result in property damage or personal injury to
yourself or to others. Always follow the safety precautions to reduce the risk of fire, electric shock and
personal injury.
NOTE:
Advises you of information or instructions vital to the operation or maintenance of the equipment.
DOUBLE INSULATION
IMPORTANT
Your power tool is double insulated. This means you are
separated from the tool's electrical system by two complete
sets of electrical insulation. This extra layer of insulation is
intended to protect the user from electrical shock due to a
break in the wiring insulation. All exposed metal parts are
isolated from the internal metal motor components with
protecting insulation. Double insulated tools do not need to
be grounded.
Servicing of a tool with double insulation requires extreme
care and knowledge of the system and should be performed
onlybyaqualifiedservicetechnician.Forservicewesuggest
you return the tool to your nearest RYOBI AUTHORIZED
SERVICE CENTER for repair. When servicing use only
identical Ryobi replacement parts.
WARNING:
Do not attempt to operate this tool until you have read
thoroughly and understand completely all instructions,
safety rules, etc. contained in this manual. Failure to
comply can result in accidents involving fire, electric
shock, or serious personal injury. Save operator's manual
and review frequently for continuing safe operation, and
instructing others who may use this tool.
WARNING:
The double insulated system is intended to protect the
user from shock resulting from a break in the tool's
internal wiring. Observe all normal safety precautions
related to avoiding electrical shock.
WARNING:
WEAR YOUR
The operation of any angle grinder can result in foreign objects being thrown into your eyes,
which can result in severe eye damage. Before beginning power tool operation, always wear
safety goggles or safety glasses with side shields and a full face shield when needed. We
recommend Wide Vision Safety Mask for use over eyeglasses or standard safety glasses with
side shields. Always wear eye protection which is marked to comply with ANSI Z87.1.
SAFETY
GLASSES
FORESIGHT IS BETTER
THAN NO SIGHT
Page 3
RULES FOR SAFE OPERATION
inattention while operating power tools may result in
serious personal injury.
WARNING:
Read and understand all instructions. Failure to
follow all instructions listed below, may result in elec-
tric shock, fire and/or serious personal injury.
■ Dress properly. Do not wear loose clothing or
jewelry. Contain long hair. Keep your hair, cloth-
ing, and gloves away from moving parts. Loose
clothes, jewelry, or long hair can be caught in moving
parts.
SAVE THESE INSTRUCTIONS
■ Avoid accidental starting. Be sure switch is off
before plugging in. Carrying tools with your finger on
the switch or plugging in tools that have the switch on
invites accidents.
■ Remove adjusting keys or wrenches before turn-
ing the tool on. A wrench or a key that is left at-
tached to a rotating part of the tool may result in
personal injury.
■ Do not overreach. Keep proper footing and
balance at all times. Proper footing and balance
enables better control of the tool in unexpected situ-
ations.
Work Area
■ Keep your work area clean and well lit. Cluttered
benches and dark areas invite accidents.
■ Do not operate power tools in explosive atmo-
spheres, such as in the presence of flammable
liquids, gases, or dust. Power tools create sparks
which may ignite the dust or fumes.
■ Keep bystanders, children, and visitors away
while operating a power tool. Distractions can
cause you to lose control.
Electrical Safety
■ Double insulated tools are equipped with a
polarized plug (one blade is wider than the other).
This plug will fit in a polarized outlet only one
way. If the plug does not fit fully in the outlet,
reverse the plug. If it still does not fit, contact a
qualified electrician to install a polarized outlet.
Do not change the plug in any way. Double insu-
■ Use safety equipment. Always wear eye protec-
tion. Dust mask, non-skid safety shoes, hard hat, or
hearing protection must be used for appropriate con-
ditions.
Tool Use and Care
■ Use clamps or other practical way to secure and
support the workpiece to a stable platform. Hold-
ing the work by hand or against your body is un-
stable and may lead to loss of control.
lation
eliminates the need for the three wire
grounded power cord and grounded power supply
system.
■ Do not force tool. Use the correct tool for your
application. The correct tool will do the job better
and safer at the rate for which it is designed.
■ Do not use tool if switch does not turn it on or
off.Any tool that cannot be controlled with the switch
is dangerous and must be repaired.
■ Disconnect the plug from the power source
before making any adjustments, changing acces-
sories, or storing the tool. Such preventive safety
measures reduce risk of starting the tool acciden-
tally.
■ Store idle tools out of reach of children and other
untrained persons. Tools are dangerous in the
hands of untrained users.
■ Maintain tools with care. Keep cutting tools sharp
and clean. Properly maintained tools with sharp
cutting edges are less likely to bind and are easier
to control.
■ Avoid body contact with grounded surfaces such
as pipes, radiators, ranges and refrigerators.
There is an increased risk of electric shock if your body
is grounded.
■ Don't expose power tools to rain or wet condi-
tions. Water entering a power tool will increase the
risk of electric shock.
■ Do not abuse the cord. Never use the cord to
carry the tools or pull the plug from an outlet.
Keep cord away from heat, oil, sharp edges or
moving parts. Replace damaged cords immedi-
ately. Damaged cords increase the risk of electric
shock.
■ When operating a power tool outside, use an out-
door extension cord marked “W-A” or “W”. These
cords are rated for outdoor use and reduce the risk of
electric shock.
Personal Safety
■ Check for misalignment or binding of moving
parts, breakage of parts, and any other condi-
tion that may affect the tool's operation. If dam-
aged, have the tool serviced before using. Many
accidents are caused by poorly maintained tools.
■ Stay alert, watch what you are doing and use
common sense when operating a power tool. Do
not use tool while tired or under the influence of
drugs, alcohol, or medication. A moment of
Page 4
RULES FOR SAFE OPERATION
■ Use only accessories that are recommended by the
■ Do not enlarge or alter the center hole of the grinding
manufacturer for your model. Accessories that may
be suitable for one tool, may become hazardous when
used on another tool.
wheel as this could result in breaking it.
■ Use only the normal grinder surface. Never use the
side or upper surfaces for cutting.
■ Keep the tool and its handle dry, clean, and free
from oil and grease. Always use a clean cloth when
cleaning. Never use brake fluids, gasoline, petroleum-
based products, or any strong solvents to clean your
tool.
Service
■ Tool service must be performed only by qualified
repair personnel. Service or maintenance performed
by unqualified personnel could result in a risk of injury.
■ When servicing a tool, use only identical replace-
ment parts. Follow instructions in the Maintenance
section of this manual. Use of unauthorized parts or
failure to follow Maintenance Instructions may create
a risk of electric shock or injury.
Additional Rules for Safe Operation
■ Know your power tool. Read operator's manual care-
fully. Learn its applications and limitations as well as
the specific potential hazards related to this tool.
Following this rule will reduce the risk of electric shock,
fire, or serious injury.
■ Always wear safety glasses with side shields.
Everydayeyeglasseshaveonlyimpactresistantlenses;
they are NOT safety glasses.
Specific Safety Rules for Grinders
■ Always use proper guard with grinding wheel. A
guard protects operator from broken wheel fragments.
■ Accessories must be rated for at least the speed
recommended on the tool warning label. Wheels
and other accessories running over rated speed can
fly apart and cause injury.
■ Hold tool by insulated gripping surfaces when
performing an operation where the tool may
contact hidden wiring or its own cord. Contact with
a “live” wire will make exposed metal parts of the tool
“live” and shock the operator.
■ Grinding wheel and guard must be securely
attached as described in this operating manual before
connecting the grinder to a power source.
■ Grinding wheels must be stored in a dry place.
■ Before attaching the grinding wheel, inspect it for
visible defects. If cracked, chipped, or warped, do not
install it.
■ Do not overtighten the clamp nut on the grinding
wheel. Excessive tightening can cause the wheel to
crack during operation
■ Make sure that the guard is in good condition and
securely installed before operating grinder.
■ Do not clamp the grinder in a vise or use as a
fixed grinder.
■ Never turn on the grinder with the grinding wheel
or any rotating parts touching the workpiece.
■ Use only grinding wheels in compliance with ANSI
standard B7.1 and rated greater than 11,000 RPM.
■ Do not use the grinder if the disc flange or clamp
nut is missing or if the spindle is bent.
■ Always hold the grinder securely with two hands
while working and at all times when it is running.
■ Never cover the air vents in the motor housing
with your hands while operating the grinder.
■ Hold the tool away from your body while it is
running. Keep your hands away from the abrasive
attachments.
■ Protect your lungs. Wear a face or dust mask if the
operation is dusty.
■ Protect your hearing. Wear hearing protection during
extended periods of operation.
■ Inspect tool cords periodically and if damaged, have
repaired at your nearest authorized service center. Stay
constantly aware of cord location.
■ Check damaged parts. Before further use of the tool,
a guard or other part that is damaged should be
carefully checked to determine that it will operate
properly and perform its intended function. Check for
alignment of moving parts, binding of moving parts,
breakage of parts, mounting, and any other conditions
that may affect its operation. A guard or other part that
is damaged should be properly repaired or replaced by
an authorized service center. Following this rule will
reduce the risk of electric shock, fire, or serious injury.
■ Donotabusecord. Nevercarrytoolbycordoryank
it to disconnect from receptacle. Keep cord from
heat, oil and sharp edges. Following this rule will
reduce the risk of electric shock or fire.
■ Make sure your extension cord is in good condi-
tion. Whenusinganextensioncord, besuretouseone
heavy enough to carry the current your product will
draw. A wire gage size (A.W.G.) of at least 16 is
recommended for an extension cord 100 feet or less in
length. A cord exceeding 100 feet is not recommended.
If in doubt, use the next heavier gage. The smaller the
gage number, the heavier the cord. An undersized cord
will cause a drop in line voltage resulting in loss of power
and overheating.
■ Inspect for and remove all foreign objects from
workpiece before grinding. Following this rule will
reduce the risk of serious personal injury.
■ Dust and waste materials should not be allowed
to build up in the workshop. Hot metal sparks
could start a fire.
Page 5
RULES FOR SAFE OPERATION
■ Drugs, Alcohol, Medication. Do not operate tool
while under the influence of drugs, alcohol, or any
medication. Following this rule will reduce the risk of
electric shock, fire, or serious injury.
WARNING:
Some dust created by power sanding, sawing, grinding,
drilling, and other construction activities contains
chemicals known to cause cancer, birth defects or
other reproductive harm. Some examples of these
chemicals are:
■ Keep hands away from grinding area. Following this
rule will reduce the risk of serious personal injury.
WARNING:
• lead from lead-based paints,
• crystalline silica from bricks and cement and other
masonry products, and
• arsenic and chromium from chemically-treated
lumber.
Run wire brush at operating speed for at least one
minute before applying to workpiece. Never stand in
line with the brush. Always use guard on grinder with
wire wheel brush accessory. Failure to heed this warn-
ing can result in serious personal injury.
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.
■ Save these instructions. Refer to them frequently
and use them to instruct others who may use this tool.
If you loan someone this tool, loan them these instruc-
tions also.
SAVE THESE INSTRUCTIONS
SYMBOLS
Important: Some of the following symbols may be used on your tool. Please study them and learn their meaning.
Proper interpretation of these symbols will allow you to operate the tool better and safer.
SYMBOL
NAME
DESIGNATION/EXPLANATION
V
Volts
Voltage
A
Amperes
Hertz
Current
Hz
W
Frequency (cycles per second)
Watt
Power
min
Minutes
Alternating Current
Time
Type or a characteristic of current
n
No Load Speed
Rotational speed, at no load
0
Designates Double Insulated
Construction tools
Class II Construction
Revolutions, strokes, surface speed,
orbits etc. per minute
.../min
Revolutions or Reciprocation Per Minute
Indicates danger, warning or caution.
It means attention!!! Your safety is
involved.
Safety Alert Symbol
Page 6
ELECTRICAL
EXTENSION CORDS
ELECTRICAL CONNECTION
When using a power tool at a considerable distance from the
power source, use an extension cord heavy enough to carry
the current that the tool will draw. An undersized extension
cord will cause a drop in line voltage, resulting in a loss of
power and causing the motor to overheat. Use the chart
provided below to determine the minimum wire size required
in an extension cord. Only round jacketed cords listed by
Underwriter's Laboratories (UL) should be used.
Your grinder has a precision built electric motor. It should be
connected to a power supply that is 120 volts, 60Hz, AC
only (normal household current). Do not operate this tool
on direct current (DC). A substantial voltage drop will cause
a loss of power and the motor will overheat. If your tool does
not operate when plugged into an outlet, double-check the
power supply.
Length of Extension Cord
Wire Size (A.W.G.)
CAUTION:
Keep the cord away from the work area and position the
cord so that it will not be caught on materials or other
objects during grinding.
Up to 25
26 to 50
51 to 100
16
14
12
When working with the tool outdoors, use an extension cord
that is designed for outside use. This is indicated by the
letters WA on the cord's jacket.
Before using an extension cord, inspect it for loose or
exposed wires and cut or worn insulation.
UNPACKING
With the exception of the side handle and accessory wheels,
youranglegrinderhasbeenshippedcompletelyassembled.
PACKING LIST
Angle Grinder with Guard
Carrying Case
■ Carefully remove the grinder and accessories from the
box. Make sure that all items listed in the packing list are
included.
Grinding Wheel (1)
Wire Wheel Brush (1)
Abrasive Mop Disc (1)
Side Handle
■ Inspect grinder carefully to make sure no breakage or
damage has occurred during shipping.
■ If any parts are damaged or missing, call 1-800-525-
2579 to obtain replacement parts before attempting to
operate grinder.
Wrench
Operator's Manual
Warranty Registration Card
■ Do not discard the packing material until you have
carefully inspected and satisfactorily operated grinder.
WARNING:
If any parts are missing, do not operate your grinder until
the missing parts are replaced. Failure to do so could
result in possible serious personal injury.
Page 7
FEATURES
KNOW YOUR ANGLE GRINDER
Before attempting to use your grinder, familiarize yourself
with all operating features and safety requirements.
See Figure 1.
Makesureallgrindingwheels andrecommendedaccessories
are in accordance with listed specifications for this tool. For
example, do not use grinding wheels that are rated at less
than 11,000 RPM.
Spindle Lock Button
The spindle lock button secures the spindle so that only one
wrench is needed to change the grinding wheel.
Switch with Lock-on Feature
Your grinder has a conveniently located switch. It also has a
lock-on feature that allows the grinder to be locked in the on
position when continuous operation for extended periods of
time is required.
Guard
APPLICATIONS
A protective guard has been provided on your grinder. It
deflects sparks and metal chips during use.
(Use only for the purposes listed below)
■ Grinding metals.
■ Sanding wood or metal surfaces.
■ Wire brushing rusted or painted surfaces.
Heavy Duty Motor
Your angle grinder has a powerful motor with sufficient
power to handle tough grinding jobs that require heavy duty
performance.
WARNING:
Do not allow familiarity with your grinder to make you
careless. Remember that a careless fraction of a second
is sufficient to inflict severe injury.
Side Handle
The side handle provided, stabilizes your grinder and must
be used during all operations. In addition to maintaining safe
control during use, the side handle also provides convenient
ease of operation for the operator.
SPINDLE
LOCK BUTTON
LOCK-ON
BUTTON
TRIGGER SWITCH
SIDE HANDLE
GUARD
GRINDING WHEEL
Fig. 1
ASSEMBLY
WARNING:
GEAR
HOUSING
Your grinder should never be connected to power supply
when you are assembling parts, making adjustments,
installingorremovinggrindingwheels,orwhennotinuse.
Disconnectingyourgrinderwillpreventaccidentalstarting
that could cause serious injury.
INSTALLING THE SIDE HANDLE
See Figure 2.
■ Unplug your grinder.
SIDE
HANDLE
Fig. 2
Page 8
ASSEMBLY
CLAMP NUT TURNED
INCORRECT
CLAMP NUT TURNED
INCORRECT
TO
TIGHTEN
WRENCH
CLAMP NUT
TURNED CORRECT
CLAMP NUT
TURNED CORRECT
TO
LOOSEN
TO
TIGHTEN
TO
TIGHTEN
CLAMP
NUT
GRINDING
WHEEL
ABRASIVE
MOP DISC
TO
LOOSEN
TO
LOOSEN
WIRE
WHEEL BRUSH
DISC
FLANGE
SPINDLE
DISC
FLANGE
DISC
FLANGE
FLAT(S)
SPINDLE
LOCK BUTTON
Fig. 3A
Fig. 3B
Fig. 3C
■ Place the accessory wheel over the spindle.
WARNING:
Failure to unplug your grinder could result in accidental
starting causing serious injury.
WARNING:
Always install grinding wheel and abrasive mop disc with
the depressed center against the disc flange as shown
above. Failure to do so will cause the grinding wheel to
crack when tightening the clamp nut. This could result in
seriouspersonalinjurybecauseoflooseparticlesbreaking
off and being thrown from the grinder. Do not overtighten.
■ Install the side handle by screwing it into the side of the
gear housing.
Note: The handle can be installed on either the left or
right side of the grinder, depending on operator prefer-
ence. It must always be used to prevent loss of control
and possible serious injury.
■ To install grinding wheel and wire wheel brush: Thread
the clamp nut on the spindle with the flat side of nut facing
up. Fit raised, small diameter portion of the clamp nut into
the hole in the wheel and finger tighten. See figures 3A
and 3B.
■ To install abrasive mop disc: Thread the clamp nut on the
spindle with the flat side of nut facing down. Finger
tighten. See figure 3C.
■ Depress the spindle lock button and rotate the wheel
clockwise until the spindle locks in position.
■ Securely tighten the clamp nut with the wrench provided.
Do not overtighten.
■ Tighten side handle securely.
INSTALLING ACCESSORY WHEELS
See Figures 3A, 3B, and 3C.
■ Unplug your grinder.
WARNING:
Failure to unplug your grinder could result in accidental
starting causing serious injury.
■ Your grinder is shipped with the disc flange and clamp
nut attached to the spindle.
■ Depress spindle lock button and rotate clamp nut until
spindle locks. To prevent damage to the spindle or
spindle lock, always allow motor to come to a complete
stop before engaging spindle lock.
■ Loosen and remove clamp nut from spindle. Do not
remove disc flange.
WARNING:
Wire wheel brush bristles will bend during use and show
their direction of rotation. When reusing the wire wheel
brush, always mount it to rotate in the same direction as
in prior use. Failure to heed this warning can result in
bristle breaking and extreme vibration of the wire wheel
brush that could result in serious personal injury.
■ Make sure flats on the bottom of disc flange are engaged
with flats on spindle.
Page 9
ADJUSTMENTS
A
WARNING:
Before connecting your grinder to power supply, always
check to be sure switch is not in lock-on position. Failure
to do so could result in accidental starting of your grinder
resulting in possible serious injury.
GUARD LOCATION
The guard on your grinder should be correctly installed
depending on which side the handle is mounted. Never use
your grinder without the guard correctly in place.
Figures 4-6 show correct and incorrect locations of the
guard.
CORRECT
LOCATION OF GUARD IS
BETWEEN POINTS A AND B
Fig. 4
WARNING:
B
Never place the guard so that it is on front of the grinder as
showninfigure6. Thiscouldresultinseriousinjurybecause
sparks and loose particles thrown from the grinding wheel
would be directed toward the operator. Always place the
guard in the correct location as shown in figures 4 and 5.
OPERATION
WARNING:
Fig. 5
■ Always wear safety glasses and keep guard in place
when grinding.
■ Hot metal sparks from metal grinding can cause a fire.
Avoid spark contact with flammable materials such as
saw dust or clothing.
INCORRECT
LOCATION OF GUARD
■ Grinding wheels must be free of fissures and cracks.
Fissures and cracks can cause a grinding wheel to
shatter resulting in possible serious injury.
Thoroughly inspect a new grinding wheel before it is
installed on the grinder.
1. Use a wooden hammer for the inspection.
2. Using the hammer, lightly tap all around the wheel,
carefully listening to the resulting sounds.
3. Any places with fissures or cracks will result in a
different sound.
Do not use a wheel containing fissures or cracks.
Fig. 6
When installing a new grinding wheel, a no load
revolution test of approximately one minute must be
carried out with the grinding wheel facing a safe
direction, i.e. away from people or objects.
WARNING:
Do not attempt to operate this tool until you have read
thoroughly and understand completely all instructions,
safety rules, etc. contained in this manual. Failure to
comply can result in accidents involving fire, electric
shock, or serious personal injury. Save operator's manual
and review frequently for continuing safe operation, and
instructing others who may use this tool.
DANGER:
Never attach a wood cutting or carving blade of any
type to this angle grinder. It is only designed for
grinding, sanding, or wire brushing. Use for any other
purposeisnotrecommendedandcreatesahazardwhich
will result in serious injury.
Page 10
OPERATION
CAUTION:
Never cover air vents. They must always be open for
proper motor cooling.
SWITCH
See Figure 7.
To turn your grinder on, depress the trigger switch. Release
the trigger switch to turn the grinder off.
LOCK-ON FEATURE
See Figure 7.
LOCK-ON
BUTTON
Your grinder has a lock-on feature that is convenient when
continuousoperationforextendedperiodsoftimeisrequired.
To lock-on, push the trigger switch, push in the lock button
located on the side of the handle, then while holding the lock
button pushed in, release the trigger switch. To release the
lock, depress the trigger switch and release it.
TRIGGER SWITCH
Fig. 7
GRINDING, SANDING, BRUSHING
See Figure 8.
WARNING:
Inspect wire wheel brush before each use. Never use
one that is rusted, damaged or not marked for a
minimum speed of 11,000 RPM. Failure to heed this
warning can result in serious personal injury.
5° TO 15°
Fig. 8
Always carefully select and use grinding wheels that are
recommended for the material to be ground. Make sure that
the minimum operating speed of any accessory wheel
selected is not less than 11,000 RPM. The grinding wheel
provided with your grinder is suitable for grinding welds,
preparing surfaces to be welded, grinding structural steel,
and grinding stainless steel.
The key to efficient operation begins by controlling the
pressure and surface contact between the grinding wheel
and workpiece. Flat surfaces are ground at an acute angle,
normally between 5 to 15 degrees.
Formaximumcontrol, holdthegrinderinfrontandawayfrom
you with both hands, keeping the grinding wheel clear of the
workpiece. Start your grinder and let the motor and grinding
wheel build up to full speed. Gradually lower grinder until the
grinding wheel contacts the workpiece.
The wire wheel brush is suitable for removing paint or rust
from metal surfaces. The abrasive mop disc is suitable for
sanding flat metal or wood surfaces.
For best results keep the grinder tilted at an angle from 5 to
15 degrees and continuously moving at a steady, consistent
pace. Move the grinder back and forth or up and down over
the work area. Keep the grinder moving so that an excessive
amount of material is not removed from one area. If the
grinder is held in one spot too long, it will gouge and cut
grooves in the workpiece. If the grinder is held at too sharp
an angle, it will also gouge the workpiece because of
concentration of pressure on a small area.
Secure all work before beginning any operation. Secure
small workpieces in a vise or clamp to a workbench.
DANGER:
Never use your grinder with the guard removed. It has
been designed for use only with the guard installed.
Attempting to use grinder with guard removed will result
in loose particles being thrown against the operator
resulting in serious personal injury.
Usejustenoughpressuretokeepthegrinderfromchattering
or bouncing. Heavy pressure will decrease its speed and put
a strain on the motor. Normally the weight of the tool alone
is adequate for most grinding jobs. Use light pressure when
grinding jagged edges or loose bolts where there is the
potential for the grinder to snag on the metal edge.
WARNING:
Never use your grinder without wearing eye protection.
Following this rule will reduce the risk of serious personal
injury.
Lift the grinder away from the workpiece before turning your
grinder off.
Page 11
OPERATION
WARNING:
In normal wire brushing operations, the material being removed and brush bristles will fly off (up to 50 or more feet) with
considerable force. The potential for serious injury exists. To protect against this hazard, operators and others in the work
area must wear protective clothing and safety goggles, or full face shields worn over safety glasses with side shields.
MAINTENANCE
■ Reassemble disc flange, grinding wheel, and clamp nut.
GUARD REPLACEMENT
Refer to "INSTALLING THE ACCESSORY WHEELS"
instructions on page 9.
See Figure 9.
After extended use, the guard may become worn and need
adjustments or replacing. If you drop your grinder and
damage the guard it may also be necessary for you to
replace it.
■ Securely tighten the clamp nut with the wrench pro-
vided.
WARNING:
When servicing use only identical Ryobi replacement
parts. Use of any other parts may create a hazard or
cause product damage.
PROCEED AS FOLLOWS WHEN REPLACEMENT IS
REQUIRED:
■ Unplug your grinder.
WARNING:
Failure to unplug your grinder could result in accidental
starting causing serious injury.
TO
TIGHTEN
WRENCH
■ Remove and reassemble parts as shown in figure 9.
■ Depress spindle lock button and rotate clamp nut until
CLAMP
NUT
TO
LOOSEN
spindle locks.
■ Using the wrench provided, loosen and remove clamp
nut from spindle.
GRINDING
WHEEL
■ Remove accessory wheel and disc flange.
■ Using a screwdriver, loosen the clamp screw until the
guard can be adjusted or removed.
■ If you are making adjustments, rotate the guard to its
correct position as shown in figures 4, 5, and 9, then
retighten clamp screw securely. Never use your grinder
without the guard in place and properly adjusted.
See Figures 4 and 5.
DISC
FLANGE
Note: Be sure the tabs on the guard are seated in the
groove in the bearing cap.
GUARD
■ If you are replacing the guard, loosen the clamp screw
until the guard can be removed from the bearing cap.
CLAMP
SCREW
■ Place the new guard on the shoulder of the bearing cap.
See Figure 9.
Note: If the new guard will not fit, loosen the clamp
screw until they slide over the bearing cap.
SPINDLE
■ Rotate guard to the correct position as shown in figure 9.
■ Tighten clamp screw securely.
BEARING CAP
Note: Be sure the tabs on the guard are seated in the
groove in the bearing cap.
FLAT(S)
SPINDLE
LOCK BUTTON
Fig. 9
Page 12
MAINTENANCE
GENERAL
WARNING:
Always wear safety goggles or safety glasses with side
shieldsduringpowertooloperationorwhenblowingdust.
If operation is dusty, also wear a dust mask.
Avoidusingsolventswhencleaningplasticparts.Mostplastics
are susceptible to damage from various types of commercial
solvents and may be damaged by their use. Use clean cloths
to remove dirt, carbon dust, etc.
WARNING:
LUBRICATION
Do not at any time let brake fluids, gasoline, petroleum-
based products, penetrating oils, etc. come in contact
with plastic parts. They contain chemicals that can
damage, weaken, or destroy plastic.
All of the bearings in this tool are lubricated with a sufficient
amount of high grade lubricant for the life of the unit under
normaloperatingconditions. Therefore,nofurtherlubrication
is required.
WARNING:
The double insulated system is intended to protect the
user from shock resulting from a break in the tool's
internal wiring. Observe all normal safety precautions
related to avoiding electrical shock.
Page 13
OPERATOR'S MANUAL
4-1/2 in. (115 mm) Angle Grinder
Model AG451 / Double Insulated
**Ampere rating
(on tool data plate) 0-2.0
EXTENSION CORD CAUTION
2.1-3.4 3.5-5.0 5.1-7.0 7.1-12.0 12.1-16.0
When using a power tool at a considerable distance from a power
source, be sure to use an extension cord that has the capacity to
handlethecurrentthetoolwilldraw. Anundersizedcordwillcause
a drop in line voltage, resulting in overheating and loss of power.
Use the chart to determine the minimum wire size required in an
extension cord. Only round jacketed cords should be used.
Cord Length
Wire Size (A.W.G.)
25'
50'
16
16
16
16
16
16
16
16
14
16
14
12
14
14
10
14
12
—
100'
When working with a tool outdoors, use an extension cord that is
designed for outside use. This is indicated by the letters "WA" on
the cord's jacket.
CAUTION: Keep the extension cord clear of the working
area. Position the cord so that it will not get caught on workpiece,
tools, or other obstructions while you are working with a power
tool.
Before using any extension cord, inspect it for loose or exposed
wires and cut or worn insulation.
**Used on 12 gauge - 20 amp circuit.
• SERVICE
Now that you have purchased your tool, should a need ever exist for repair parts or service,
simply contact your nearest Ryobi Authorized Service Center. Be sure to provide all
pertinent facts when you call or visit. Please call 1-800-525-2579 for your nearest Ryobi
complete list of Authorized Service Centers.
• MODEL NO.
The model number of your tool will be found on a plate attached to the motor housing.
Please record the model number and serial number in the space provided below.
•
•
MODEL NUMBER
SERIAL NUMBER
AG451
RYOBI TECHNOLOGIES, INC.
1428 Pearman Dairy Road Anderson SC 29625
Post Office Box 1207
Anderson SC 29622
Phone 1-800-525-2579
983000-030
|