Milwaukee 4272-21, 4274-21 Operator's Manual

1-5/8" MAGNETIC DRILLS

PERCEUSE MAGNÉTIQUE DE 41 mm (1-5/8")
TALADROS MAGNÉTICOS DE 41 mm (1-5/8")

Cat. No.

No de cat.

4272-21
4274-21

OPERATOR'S MANUAL
MANUEL de L'UTILISATEUR
MANUAL del OPERADOR

TO REDUCE THE RISK OF INJURY, USER MUST READ AND UNDERSTAND OPERATOR'S
MANUAL.

AFIN DE RÉDUIRE LE RISQUE DE BLESSURES, L'UTILISATEUR DOIT LIRE ET BIEN
COMPRENDRE LE MANUEL DE L'UTILISATEUR.

PARA REDUCIR EL RIESGO DE LESIONES, EL USUARIO DEBE LEER Y ENTENDER EL
MANUAL DEL OPERADOR.

2

3

SYMBOLOGY

SPECIFICATIONS

Cat. No. Magnet Volts a.c. Amps No Load RPM

*Twist Drill HSS Cutter

4272-21 Electro 120 13 High 730

Low 475

1/2" 1-5/8"

4274-21 Permanent 120 13 High 730

Low 475

1/2" 1-5/8"

SPECIFIC SAFETY RULES

• Always use safety chain. Mounting can release.

• DANGER! T o reduce the risk of injury , always keep

hands, gloves, rags, clothing, etc. away from mov­ing parts and chips. Do not try to remove chips while
the cutter is rotating. Chips are sharp and can pull
objects into moving parts.

• Clean the surface before attaching the drill
stand to the work surface. Paint, rust, scale, or

uneven surfaces decrease the holding strength of
the magnet. Chips, burrs, dirt and other foreign
matter on the surface of the magnet base will also
decrease holding power.

• Do not attach magnetic base to nonmagnetic
grades of stainless steel. The magnet base WILL

NOT hold. The 4272-21 drill attaches magnetically
to 3/8" or thicker ferrous stock, and the 4274-21 to
1/4" or thicker ferrous stock. Do not use on stock
less than 1/4".

• Hold power tool by insulated gripping surfaces,

when performing an operation where the cutting
accessory may contact hidden wiring or its own
cord. Cutting accessory contacting a “live” wire may

make exposed metal parts of the power tool “live”
and could give the operator an electric shock.

• Safety Strap

• Do not use near acids or bleaching agents.

• Do not use for overhead lifting.

• Do not use strap if webbing is cut.

• Webbing must be protected from sharp edges.

• All hardware must be in line with direction of

pull for rated capacity.

• Maintain labels and nameplates. These carry

important information. If unreadable or missing,
contact a MILWAUKEE service facility for a free
replacement.

• 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 paint

• crystalline silica from bricks and cement and other
masonry products, and

• arsenic and chromium from chemically-treated
lumber.

* Requires use of 1/2" drill chuck adapter, see "Accessories."

Double Insulated

Volts

Alternating Current

Amps
No Load Revolutions per

Minute (RPM)

C

US

Underwriters Laboratories, Inc.
United States and Canada

DANGER! To reduce the risk
of injury, always keep hands,
gloves, rags, clothing, etc. away
from moving parts and chips. Do
not try to remove chips while
the cutter is rotating. Chips are
sharp and can pull objects into
moving parts.

PERSONAL SAFETY

GENERAL POWER TOOL SAFETY WARNINGS

WORK AREA SAFETY

ELECTRICAL SAFETY

POWER TOOL USE AND CARE

SERVICE

• Keep work area clean and well lit. Cluttered or
dark areas invite accidents.

• Do not operate power tools in explosive atmos­pheres, such as in the presence of fl ammable
liquids, gases or dust. Power tools create sparks

which may ignite the dust or fumes.

• Keep children and bystanders away while op­erating a power tool. Distractions can cause you

to lose control.

• Power tool plugs must match the outlet. Never
modify the plug in any way. Do not use any
adapter plugs with earthed (grounded) power
tools. Unmodifi ed plugs and matching outlets will

reduce risk of electric shock.

• Avoid body contact with earthed or grounded
surfaces, such as pipes, radiators, ranges and
refrigerators. There is an increased risk of electric

shock if your body is earthed or grounded.

• Do not 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 for
carrying, pulling or unplugging the power tool.
Keep cord away from heat, oil, sharp edges
or moving parts. Damaged or entangled cords

increase the risk of electric shock.

• When operating a power tool outdoors, use an
extension cord suitable for outdoor use. Use of

a cord suitable for outdoor use reduces the risk of
electric shock.

• If operating a power tool in a damp location is
unavoidable, use a ground fault circuit inter­rupter (GFCI) protected supply. Use of an GFCI

reduces the risk of electric shock.

• Stay alert, watch what you are doing and use
common sense when operating a power tool. Do
not use a power tool while you are tired or under
the infl uence of drugs, alcohol or medication. A

moment of inattention while operating power tools
may result in serious personal injury.

• Use personal protective equipment. Always
wear eye protection. Protective equipment such

as a dust mask, non-skid safety shoes, hard hat or
hearing protection used for appropriate conditions
will reduce personal injuries.

• Prevent unintentional starting. Ensure the
switch is in the off-position before connecting
to power source and/or battery pack, picking
up or carrying the tool. Carrying power tools with

your fi nger on the switch or energizing power tools
that have the switch on invites accidents.

• Remove any adjusting key or wrench before
turning the power tool on. A wrench or a key left

attached to a rotating part of the power tool may
result in personal injury.

• Do not overreach. Keep proper footing and bal-

ance at all times. This enables better control of the

power tool in unexpected situations.

• Dress properly. Do not wear loose clothing or
jewelry. Keep your hair and clothing away from
moving parts. Loose clothes, jewelry or long hair

can be caught in moving parts.

• If devices are provided for the connection of
dust extraction and collection facilities, ensure
these are connected and properly used. Use of

dust collection can reduce dust-related hazards.

• Do not let familiarity gained from frequent use of
tools allow you to become complacent and ig­nore tool safety principles. A careless action can

cause severe injury within a fraction of a second.

• Do not force the power tool. Use the correct
power tool for your application. The correct

power tool will do the job better and safer at the
rate for which it was designed.

• Do not use the power tool if the switch does not
turn it on and off. Any power tool that cannot be

controlled with the switch is dangerous and must
be repaired.

• Disconnect the plug from the power source and/
or remove the battery pack, if detachable, from
the power tool before making any adjustments,
changing accessories, or storing power tools.

Such preventive safety measures reduce the risk
of starting the power tool accidentally.

• Store idle power tools out of the reach of chil­dren and do not allow persons unfamiliar with
the power tool or these instructions to operate
the power tool. Power tools are dangerous in the

hands of untrained users.

• Maintain power tools and accessories. Check
for misalignment or binding of moving parts,
breakage of parts and any other condition that
may affect the power tool’s operation. If dam­aged, have the power tool repaired before use.

Many accidents are caused by poorly maintained
power tools.

• Keep cutting tools sharp and clean. Properly
maintained cutting tools with sharp cutting edges
are less likely to bind and are easier to control.

• Use the power tool, accessories and tool bits
etc. in accordance with these instructions, tak­ing into account the working conditions and
the work to be performed. Use of the power tool

for operations different from those intended could
result in a hazardous situation.

• Keep handles and grasping surfaces dry, clean
and free from oil and grease. Slippery handles

and grasping surfaces do not allow for safe handling
and control of the tool in unexpected situations.

WARNING Read all safety warnings, instructions, illustrations and specifi cations provided

with this power tool. Failure to follow all instructions listed below may result in electric shock, fi re

and/or serious injury. Save all warnings and instructions for future reference. The term "power tool" in
the warnings refers to your mains-operated (corded) power tool or battery-operated (cordless) power tool.

• Have your power tool serviced by a qualifi ed
repair person using only identical replacement
parts. This will ensure that the safety of the power

tool is maintained.

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 fi lter out microscopic particles.

4

5

1. Slide rail

2. Carrying handle

3. Feed handle

4. Magnet activation
switch (4272-21 only)

5. Magnet activation knob
(4274-21 only)

6. Speed selector

7. Motor adjustment lever

8. On(I) / Off(O) switch

9. Drill motor

OPERATION

WARNING To reduce the risk of injury,

wear safety goggles or glasses with side
shields.

ASSEMBLY

Attaching Feed Handle

1. T o attach, line up the anvil, press the center but­ton and slide the handle into place on the desired
side of the tool.

2. T o remove, press the center button and pull the
handle away from the tool.

Do not use a wrench, pipe, or any other lever in
place of the feed handle.

Motor adjustment lever

The motor adjustment lever is used to raise and
lower the motor on the slide rail. Always hold the
motor securely before loosening the adjustment
lever.

FUNCTIONAL DESCRIPTION

Typical Operation

1. Check the work surface to make sure it is clean
and free of foreign materials.

Paint, rust, scale or uneven surfaces decrease

the holding strength of the magnet. Chips, burrs,
dirt and other foreign materials on the surface
of the magnetic base will also decrease holding
power. Use a smooth, fl at fi le to keep the magnet
clean and free of nicks.

The 4272-21 drill attaches to 3/8" or thicker

ferrous stock, and the 4274-21 to 1/4" or
thicker ferrous stock. Do not use on stock
less than 1/4". The magnetic base WILL NOT
hold on nonmagnetic grades of stainless steel.

2. To install/remove cutter:

A. Unplug tool.
B. Raise the drill motor to its highest position

on the slide rail.

C. Twist the quick-change arbor. Insert the cut-

ter into the arbor and release collar. Tug on
cutter to ensure it is secure. Cutter should

be fully seated into spindle.
D. Reverse procedure to remove cutter.
NOTE: Do not remove cutter unless slug is

removed. Slug may eject unexpectedly. Avoid
contact with cutter tips. Periodically inspect the
cutter tips for loose or damaged tips.

10. Cutting fl uid fi tting

11. Quick-change arbor

12. Safety strap bracket
(strap not shown)

13. Magnetic base

14. LED button

15. Hand pump and
tube (not shown)

1

3

2

4

5

6

7

9

8

1312

14

Fig. B

Fig. C

Fig. A

GROUNDING

WARNING Improperly connecting the

grounding wire can result in the risk of elec­tric shock. Check with a qualifi ed electrician
if you are in doubt as to whether the outlet is
properly grounded. Do not modify the plug
provided with the tool. Never remove the
grounding prong from the plug. Do not use
the tool if the cord or plug is damaged. If
damaged, have it repaired by a MILWAUKEE
service facility before use. If the plug will not
fi t the outlet, have a proper outlet installed by
a qualifi ed electrician.

Grounded Tools: Tools with Three Prong Plugs

Tools marked “Grounding Required” have a three
wire cord and three prong grounding plug. The
plug must be connected to a properly grounded
outlet (See Figure A). If the tool should electrically
malfunction or break down, grounding provides a
low resistance path to carry electricity away from
the user, reducing the risk of electric shock.
The grounding prong in the plug is connected
through the green wire inside the cord to the
grounding system in the tool. The green wire in the
cord must be the only wire connected to the tool's
grounding system and must never be attached to
an electrically “live” terminal.
Your tool must be plugged into
an appropriate outlet, properly
installed and grounded in accord­ance with all codes and ordinances.
The plug and outlet should look like
those in Figure A.

Double Insulated Tools:
Tools with Two Prong Plugs

Tools marked “Double Insulated” do not require
grounding. They have a special double insula­tion system which satisfi es OSHA requirements
and complies with the applicable standards of
Underwriters Laboratories, Inc.,
the Canadian Standard Asso­ciation and the National Elec­trical Code. Double Insulated
tools may be used in either of
the 120 volt outlets shown in
Figures B and C.

Grounded tools require a three wire extension
cord. Double insulated tools can use either a two
or three wire extension cord. As the distance from
the supply outlet increases, you must use a heavier
gauge extension cord. Using extension cords with
inadequately sized wire causes a serious drop in
voltage, resulting in loss of power and possible tool
damage. Refer to the table shown to determine the
required minimum wire size.
The smaller the gauge number of the wire, the
greater the capacity of the cord. For example, a 14
gauge cord can carry a higher current than a 16
gauge cord. When using more than one extension
cord to make up the total length, be sure each cord
contains at least the minimum wire size required.
If you are using one extension cord for more than
one tool, add the nameplate amperes and use the
sum to determine the required minimum wire size.

Guidelines for Using Extension Cords

• If you are using an extension cord outdoors, be
sure it is marked with the suffi x “W-A” (“W” in
Canada) to indicate that it is acceptable for outdoor
use.

• Be sure your extension cord is properly wired
and in good electrical condition. Always replace a
damaged extension cord or have it repaired by a
qualifi ed person before using it.

• Protect your extension cords from sharp objects,
excessive heat and damp or wet areas.

READ AND SAVE ALL

INSTRUCTIONS FOR FUTURE USE.

* Based on limiting the line voltage drop to fi ve volts at

150% of the rated amperes.

EXTENSION CORDS

Recommended Minimum Wire Gauge

For Extension Cords*

Extension Cord Length

Nameplate

Amperes

25' 50' 75' 100' 150'

0 - 2.0

2.1 - 3.4

3.5 - 5.0

5.1 - 7.0

7.1 - 12.0

12.1 - 16.0

16.1 - 20.0

18
18
18
18
16
14
12

18
18
18
16
14
12
10

18
18
16
14
12
10

--

18
16
14
12
10

--

--

16
14
12
12

--

--

--

WARNING To reduce the risk of injury,

always unplug tool before attaching or remov­ing accessories or making adjustments. Use
only specifi cally recommended accessories.
Others may be hazardous.

10

11

Cat. No. 4274-21

Cat. No. 4272-21

6

7

WARNING Do not use cutting fl uid

in an overhead or any other position that
allows cutting fl uid to enter motor or switch
enclosure.

6. Plug in tool.

7. With the on(I) / off(O) switch in the off(O) posi­tion, place the rubber tube over the cutting fl uid
fi tting. Inject cutting fl uid into the rubber tube
using the supplied hand pump. Keep hand pump
and tube away from moving parts. Lubricate
well before starting, and throughout the cutting
operation as needed.

Failure to lubricate properly will cause cutter

damage. The use of HAWG WASH® cutting fl uid
is recommended for long life of these cutters.
The operator is responsible for the application
of lubricants other than HAWG WASH® cutting
fl uid.

In overhead or vertical cutting applications, do

not use cutting fl uids. Use only lubricant pastes
or sprays recommended for high speed cutting.
Do not allow lubricant pastes and sprays to enter
tool.

WARNING To reduce the risk of injury,

do not hold workpiece by hand.

3. Select High Speed or Low Speed , depend­ing on your application.

WARNING To reduce the

risk of injury, always keep hands,
gloves, rags, clothing, etc. away
from moving parts and chips. Do
not try to remove chips while the cutter is
rotating. Chips are sharp and can pull objects
into moving parts.

8. Start the drill motor by pulling
the on(I) / off(O) switch out, by
both sides, to the on(I) position.

The drill will not operate unless
the magnet is engaged.

NOTE: If the cutter does not release from the ar-

bor when the collar is turned, use a locking pliers
to grasp the cutter above the cutter fl utes. Hold-
ing the collar securely in one hand, rotate the pli­ers clockwise to release the cutter from the arbor.

5. Use a safety strap on vertical, overhead, and
pipe applications.

A. Route the safety strap, through the lower

slots, and wrap it tightly around a solid, rigid
structure. Make sure the strap is not twisted.

WARNING To reduce the risk of in-

jury, always use a safety strap on vertical,
overhead, and pipe applications. Mounting
can release.

B. Snap the safety strap snaphooks together.

Eliminate any slack in the strap.

C. When using on a vertical surface, secure

the safety strap with a c-clamp or similar
device. This will hold the strap in place and
prevent the tool from sliding down the vertical
surface. Do not clamp to the strap. This may
damage the strap and cause it to break.

Maintaining Tool

Keep your tool in good repair by adopting a regular
maintenance program. Before use, examine the
general condition of your tool. Inspect guards,
switches, tool cord set and extension cord for dam­age. Check for loose screws, misalignment, binding
of moving parts, improper mounting, broken parts
and any other condition that may affect its safe oper­ation. If abnormal noise or vibration occurs, turn the
tool off immediately and have the problem corrected
before further use. Do not use a damaged tool.
Tag damaged tools “DO NOT USE” until repaired
(see “Repairs”).
Under normal conditions, relubrication is not neces­sary until the motor brushes need to be replaced.
After six months to one year, depending on use,
return your tool to the nearest MILWAUKEE service
facility for the following:

• Lubrication

• Brush inspection and replacement

• Mechanical inspection and cleaning (gears,
spindles, bearings, housing, etc.)

• Electrical inspection (switch, cord, armature, etc.)

• T esting to assure proper mechanical and electrical
operation

Cleaning

Clean dust and debris from vents. Keep the tool
handles clean, dry and free of oil or grease. Use
only mild soap and a damp cloth to clean your tool
since certain cleaning agents and solvents are
harmful to plastics and other insulated parts. Some
of these include: gasoline, turpentine, lacquer thin­ner, paint thinner, chlorinated cleaning solvents,
ammonia and household detergents containing
ammonia. Never use fl ammable or combustible
solvents around tools.

Repairs

If your tool is damaged, return the entire tool to the
nearest service center.

MAINTENANCE

For a complete listing of accessories refer
to your MILWAUKEE catalog or go online to
www.milwaukeetool.com. To obtain a catalog, con­tact your local distributor or service center.

ACCESSORIES

WARNING Excessive force on the feed

handle will break magnet free.

9. Even large bits only require a small amount of
pressure on the feed handle.

When feeding the cutter into the material, apply

only enough force to produce a curled chip. Ap­plying too little force will result in small broken
chips and increased cutting time. Applying too
much force will cause overheating of the cutter
resulting in short cutter life. Overheating of the
cutter can be noticed when cutter and chips
turn brown or blue. Excessive force can cause
the cutter to slow down to a point where cutting
time will increase. The use of cutting lubricants
will reduce cutting heat and increase cutter life.

Use less feed pressure when slotting or notch-

ing because there is less support for the cutting
edges in these situations.

10. Keep constant pressure throughout the entire

operation to prevent chips and burrs from falling
under the cutting edges. Cutting debris under
the cutter can make cutting diffi cult or impos-
sible. Continue lubricating as necessary.

11. When the cut is complete, withdraw the cutter

while the spindle is still rotating.

12. Stop the drill motor by pushing in the on(I) / off(O)

switch.

13. When the spindle has stopped rotating, use

a pliers to remove cutting debris and chips
from the cutter and spindle. Use care to avoid
damaging the cutter teeth.

14.

The center pin is spring loaded. Provide protec-

tion from ejected slug for people and property
below cutting area.

15. Firmly grip the tool to disengaging the magnet.

For the 4272-21, push the magnet switch to
disengage. For the 4274-21, rotate the magnet
knob.

16. When drilling on pipe using the 4274-21, use

the accessory pipe adaptor 48-10-0130 and the
safety strap.

4.

For the 4272-21, position the tool so the center
pin is directly over the desired cutting location.
Push the magnetic activation switch to engage
the magnet. The drill will not operate unless the
magnet is engaged.

For the 4274-21, position the tool so the center

pin is directly over the desired cutting location.
Rotate the magnet knob to engage the magnet.
The magnet icons will align . The drill will not

operate unless the magnet is engaged.

WARNING

• Do not use cutting fl uid in an overhead or

any other position that allows cutting fl uid
to enter motor or switch enclosure.

• Wet connections are shock haz-

ards. Prevent cutting fl uid from
traveling along cord and contact­ing the outlet, extension cord
connections or tool plug. Each
time tool is plugged in, elevate extension
cord or gang box connections and ar­range a drip loop. If plug or connections
get wet, turn power off to outlet before
unplugging tool.

WARNING T o reduce the risk of injury ,

always unplug your tool before performing
any maintenance. Never disassemble the tool
or try to do any rewiring on the tool’s electrical
system. Contact a MILWAUKEE service facility
for ALL repairs.

WARNING T o reduce the risk of injury ,

electric shock and damage to the tool, never
immerse your tool in liquid or allow a liquid
to fl ow inside the tool.

WARNING T o reduce the risk of injury,

always unplug the tool before attaching or
removing accessories. Use only specifi cally
recommended accessories. Others may be
hazardous.