TOOL USE AND CARE
• Use clamps or other practical way to secure and support the workpiece to a stable
platform. Holding the work by hand or against your body is unstable and may lead to loss
• 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
accessories, or storing the tool. Such preventative safety measures reduce the risk of starting
the tool accidentally.
• 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.
• Check for misalignment or binding of moving parts, breakage of parts, and any other
condition that may affect the tools operation. If damaged, have the tool serviced
before using. Many accidents are caused by poorly maintained tools.
• Use only accessories that are recommended by the manufacturer for your model.
Accessories that may be suitable for one tool, may become hazardous when used on
• 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 replacement 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.
Special Safety Instructions For Sanders
• Always wear eye protection and a respirator when sanding.
• Sanding of lead based paint is not recommended. See “Precautions” section for
additional information before sanding paint.
• Do not operate the unit without the dust collection bag. (DW421, and DW423)
• Empty dust bag frequently, especially when sanding resin coated surfaces such as
polyurethane, varnish, shellac, etc. Dispose of coated dust particles according to the finsh
manuafacturer’s guildelings, or place in a metal can with a tight fitting metal lid. Remove
coated dust particles from the premises dailyThe accumulation of fine sanding dust particles
may self ignite and cause fire.
• Replace worn CFS disc when it causes high tool rpm. High tool rpm caused by a worn
out CFS disc may result in separation of sanding pad from the sander, possibly causing
personal injury. for instructions on replacing the CFS disc, see the section of this manual titled
CAUTION: Wear appropriate personal hearing protection during use. Under some
conditions and duration of use, noise from this product may contribute to hearing loss.
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:
• lead from lead-based paints,
• crystalline silica from bricks and cement and other masonry products, and
• arsenic and chromium from chemically-treated lumber (CCA).
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
• Avoid prolonged contact with dust from power sanding, sawing, grinding, drilling,
and other construction activities. Wear protective clothing and wash exposed areas
with soap and water. Allowing dust to get into your mouth, eyes, or lay on the skin may
promote absorption of harmful chemicals.
• The label on your tool may include the following symbols.
V......................volts A ................amperes
min ..................minutes ..............alternating current
o ..............no load speed
Class II Construction …/min ........revolutions or reciprocation
....................safety alert symbol
WALT tool is powered by a D
EWALT built motor. Be sure your power supply agrees with
the nameplate marking. (Volts, 120 AC only). Voltage decrease of more than 10% will cause
loss of power and overheating. All D
EWALT tools are factory tested; if this tool does not operate,
check the power supply.
Attaching Sanding Discs
Your sander is designed to use 5” (127 mm) sanding discs. Discs for DW421 and DW423 have
an 8 hole dust extraction pattern and hook and loop attachment. Discs for the DW420 have no
holes and attach using pressure sensitive adhesive (PSA). To attach paper to the sanding pad:
1. Turn off and unplug the tool.
2. Turn the sander over so that the sanding pad is facing upward.
3. Clean dust from the vinyl pad face.
4. Hold the pad with one hand to keep it from rotating.
5. With the other hand, align the holes if they are present, and place the disc directly on top of the
pad. (see FIG 1).
NOTE: Do not use sanding screen (e.g. screen used for sanding drywall) directly on the hook and
loop pad. The screen will not hold and will damage the hooks on the pad. The hooks on the pad
will wear very rapidly if left in contact with the work surface while the tool is operating.
To turn the unit on, depress the side of the dust protected switch that corresponds to the symbol
“I”. To turn the tool off, depress the side of the switch that corresponds to the symbol “O”. See
Speed Control Dial (DW423)
The speed control dial allows you to increase or decrease speed from 7,000 - 12,000 Orbits Per
Minute. The optimal speed setting for each application is very much dependent on personal
preference. Generally, you will want to use a higher setting on harder materials and a lower
setting on softer materials. Material removal rate increases as speed increases.
Dust Extraction (DW421, DW423)
Your sander comes equipped with a cloth bag to collect the dust generated during sanding. It was
designed to be very durable and efficient yet easy to empty. To empty the dust collection bag:
1. Turn off and unplug tool.
2. While holding the canister, twist to unlock and remove the adapter. (FIG. 3)
3. Gently empty the bag and shake out the adapter.(FIG. 4)
You may notice that all the dust will not come free from the bag. This will not affect sanding
performance but will reduce the sander’s dust collection efficiency. To restore your sander’s dust
collection efficiency, depress the spring inside the dust bag when you are emptying it and tap it
on the side of the trash can or dust receptacle.
MANUAL DE INSTRUCCIONES
Random Orbit Palm Sanders
Ponceuses de finition orbitale excentrique
Lijadoraes de órbita aleatoria
INSTRUCTIVO DE OPERACIÓN, CENTROS DE SERVICIO Y
PÓLIZA DE GARANTÍA. ADVERTENCIA: LÉASE ESTE
INSTRUCTIVO ANTES DE USAR EL PRODUCTO.
IF YOU HAVE ANY QUESTIONS OR COMMENTS ABOUT THIS OR ANY DEWALT TOOL,
CALL US TOLL FREE AT:
General Safety Instructions for All Tools
WARNING! Read and understand all instructions. Failure to follow all instructions listed
below, may result in electric shock, fire and/or serious personal injury.
SAVE THESE INSTRUCTIONS
• Keep your work area clean and well lit. Cluttered benches and dark areas invite accidents.
• Do not operate power tools in explosive atmospheres, such as in the presence of
flammable liquids, gases, or dust. Power tools create sparks which may ignite the dust or
• Keep bystanders, children, and visitors away while operating a power tool. Distractions
can cause you to lose control.
• 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 insulation
eliminates the need for the three wire grounded power cord and grounded power supply
• 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 conditions. 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 immediately. Damaged cords increase the risk of electric shock.
• When operating a power tool outside, use an outdoor extension cord marked “W-A”
or “W.” These cords are rated for outdoor use and reduce the risk of electric shock.
Recommended Minimum Wire Size for Extension Cords
Total Length of Cord
25 ft. 50 ft. 75 ft. 100 ft. 125 ft. 150 ft. 175 ft.
7.6 m 15.2 m 22.9 m 30.5 m 38.1 m 45.7 m 53.3 m
18 AWG 18 AWG16 AWG 16 AWG 14 AWG 14 AWG 12 AWG
• 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 inattention while operating power tools may result in serious
• Dress properly. Do not wear loose clothing or jewelry. Contain long hair. Keep your
hair, clothing , and gloves away from moving parts. Loose clothes, jewelry, or long hair
can be caught in moving parts. Air vents often cover moving parts and should also be
• 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 turning the tool on. A wrench or a key that
is left attached 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 situations.
• Use safety equipment. Always wear eye protection. Dust mask, non-skid safety shoes,
hard hat, or hearing protection must be used for appropriate conditions.
DEWALT Industrial Tool Co., 701 East Joppa Road, Baltimore, MD 21286
Printed in U.S.A. (AUG02-CD-1) Form No. 613265-00 DW420, etc.
The following are trademarks for one or more DEWALT power tools: the yellow and black color
scheme; the “D” shaped air intake grill; the array of pyramids on the handgrip; the kit box
configuration; and the array of lozenge-shaped humps on the surface of the tool.
Questions? See us in the World Wide Web at www.dewalt.com
Model Disc Attachment Hole
Sander Size Method Pattern
DW420 5" PSA None
DW421 5" Hook & Loop 8 holes
DW423 5" Hook & Loop 8 Holes