Makita DTW451 User manual

INSTRUCTION MANUAL
Cordless Impact Wrench
DTW451
ENGLISH: Original instructions
Read before use.

2ENGLISH
SPECIFICATIONS
Model DTW451
Capacities Standard bolt M12 - M22
High tensile bolt M12 - M16
Drive shank 11.2 mm Hex.
No load speed (min-1)1,900
Impacts per minute 2,200
Max. fastening torque 440 N•m
Overall length 273 mm
Net weight 3.2 - 3.5 kg
Rated voltage D.C. 18 V
• Due to our continuing program of research and development, the specications herein are subject to change
without notice.
• Specications may differ from country to country.
• The weight may differ depending on the attachment(s), including the battery cartridge. The lightest and heavi-
est combination, according to EPTA-Procedure 01/2014, are shown in the table.
Applicable battery cartridge and charger
Battery cartridge BL1815N / BL1820 / BL1820B / BL1830 / BL1830B / BL1840 /
BL1840B / BL1850 / BL1850B / BL1860B
Charger DC18RC / DC18RD / DC18RE / DC18SD / DC18SE / DC18SF
• Some of the battery cartridges and chargers listed above may not be available depending on your region of
residence.
WARNING: Only use the battery cartridges and chargers listed above. Use of any other battery cartridges
and chargers may cause injury and/or re.
Symbols
The following show the symbols used for the equip-
ment. Be sure that you understand their meaning before
use.
Read instruction manual.
Ni-MH
Li-ion
Only for EU countries
Do not dispose of electric equipment or
battery pack together with household waste
material!
In observance of the European Directives,
on Waste Electric and Electronic
Equipment and Batteries and Accumulators
and Waste Batteries and Accumulators
and their implementation in accordance
with national laws, electric equipment and
batteries and battery pack(s) that have
reached the end of their life must be col-
lected separately and returned to an envi-
ronmentally compatible recycling facility.
Intended use
The tool is intended for fastening bolts and nuts.
General power tool safety warnings
WARNING: Read all safety warnings, instruc-
tions, illustrations and specications provided
with this power tool. Failure to follow all instructions
listed below may result in electric shock, re and/or
serious injury.
Save all warnings and instruc-
tions for future reference.
The term "power tool" in the warnings refers to your
mains-operated (corded) power tool or battery-operated
(cordless) power tool.
Work area safety
1. Keep work area clean and well lit. Cluttered or
dark areas invite accidents.
2. Do not operate power tools in explosive atmo-
spheres, such as in the presence of ammable
liquids, gases or dust. Power tools create sparks
which may ignite the dust or fumes.
3. Keep children and bystanders away while
operating a power tool. Distractions can cause
you to lose control.
Electrical Safety
1. 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. Unmodied plugs and matching outlets will
reduce risk of electric shock.

3ENGLISH
2. Avoid body contact with earthed or grounded
surfaces, such as pipes, radiators, ranges and
refrigerators. There is an increased risk of elec-
tric shock if your body is earthed or grounded.
3. Do not expose power tools to rain or wet con-
ditions. Water entering a power tool will increase
the risk of electric shock.
4. 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.
5. 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.
6. If operating a power tool in a damp location
is unavoidable, use a residual current device
(RCD) protected supply. Use of an RCD reduces
the risk of electric shock.
7. Power tools can produce electromagnetic
elds (EMF) that are not harmful to the user.
However, users of pacemakers and other similar
medical devices should contact the maker of their
device and/or doctor for advice before operating
this power tool.
Personal Safety
1. 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 inuence of drugs, alcohol or med-
ication. A moment of inattention while operating
power tools may result in serious personal injury.
2. 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.
3. 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 nger on the switch or energising power tools
that have the switch on invites accidents.
4. 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.
5. Do not overreach. Keep proper footing and
balance at all times. This enables better control
of the power tool in unexpected situations.
6. Dress properly. Do not wear loose clothing or
jewellery. Keep your hair and clothing away
from moving parts. Loose clothes, jewellery or
long hair can be caught in moving parts.
7. 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.
8. 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.
9. Always wear protective goggles to protect
your eyes from injury when using power tools.
The goggles must comply with ANSI Z87.1 in
the USA, EN 166 in Europe, or AS/NZS 1336
in Australia/New Zealand. In Australia/New
Zealand, it is legally required to wear a face
shield to protect your face, too.
It is an employer's responsibility to enforce
the use of appropriate safety protective equip-
ments by the tool operators and by other per-
sons in the immediate working area.
Power tool use and care
1. 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.
2. 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.
3. Disconnect the plug from the power source
and/or remove the battery pack, if detachable,
from the power tool before making any adjust-
ments, changing accessories, or storing power
tools. Such preventive safety measures reduce
the risk of starting the power tool accidentally.
4. Store idle power tools out of the reach of chil-
dren 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.
5.
Maintain power tools and accessories. Check for
misalignment or binding of moving parts, break-
age 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.
6. Keep cutting tools sharp and clean. Properly
maintained cutting tools with sharp cutting edges
are less likely to bind and are easier to control.
7. Use the power tool, accessories and tool bits
etc. in accordance with these instructions, tak-
ing 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.
8. 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.

4ENGLISH
9. When using the tool, do not wear cloth work
gloves which may be entangled. The entangle-
ment of cloth work gloves in the moving parts may
result in personal injury.
Battery tool use and care
1. Recharge only with the charger specied by
the manufacturer. A charger that is suitable for
one type of battery pack may create a risk of re
when used with another battery pack.
2. Use power tools only with specically desig-
nated battery packs. Use of any other battery
packs may create a risk of injury and re.
3. When battery pack is not in use, keep it away
from other metal objects, like paper clips,
coins, keys, nails, screws or other small metal
objects, that can make a connection from one
terminal to another. Shorting the battery termi-
nals together may cause burns or a re.
4. Under abusive conditions, liquid may be
ejected from the battery; avoid contact. If con-
tact accidentally occurs, ush with water. If
liquid contacts eyes, additionally seek medical
help. Liquid ejected from the battery may cause
irritation or burns.
5. Do not use a battery pack or tool that is dam-
aged or modied. Damaged or modied batteries
may exhibit unpredictable behaviour resulting in
re, explosion or risk of injury.
6. Do not expose a battery pack or tool to re or
excessive temperature. Exposure to re or tem-
perature above 130 °C may cause explosion.
7. Follow all charging instructions and do not
charge the battery pack or tool outside the
temperature range specied in the instruc-
tions. Charging improperly or at temperatures
outside the specied range may damage the
battery and increase the risk of re.
Service
1. Have your power tool serviced by a qualied
repair person using only identical replacement
parts. This will ensure that the safety of the power
tool is maintained.
2. Never service damaged battery packs. Service
of battery packs should only be performed by the
manufacturer or authorized service providers.
3. Follow instruction for lubricating and chang-
ing accessories.
Cordless impact wrench safety
warnings
1. Hold the power tool by insulated gripping
surfaces, when performing an operation
where the fastener may contact hidden wiring.
Fasteners contacting a "live" wire may make
exposed metal parts of the power tool "live" and
could give the operator an electric shock.
2. Wear ear protectors.
3. Check the impact socket carefully for wear,
cracks or damage before installation.
4. Hold the tool rmly.
5. Keep hands away from rotating parts.
6. Always be sure you have a rm footing.
Be sure no one is below when using the tool in
high locations.
7. The proper fastening torque may differ
depending upon the kind or size of the bolt.
Check the torque with a torque wrench.
SAVE THESE INSTRUCTIONS.
WARNING: DO NOT let comfort or familiarity
with product (gained from repeated use) replace
strict adherence to safety rules for the subject
product.
MISUSE or failure to follow the safety rules stated
in this instruction manual may cause serious
personal injury.
Important safety instructions for
battery cartridge
1. Before using battery cartridge, read all instruc-
tions and cautionary markings on (1) battery
charger, (2) battery, and (3) product using
battery.
2. Do not disassemble battery cartridge.
3. If operating time has become excessively
shorter, stop operating immediately. It may
result in a risk of overheating, possible burns
and even an explosion.
4. If electrolyte gets into your eyes, rinse them
out with clear water and seek medical atten-
tion right away. It may result in loss of your
eyesight.
5. Do not short the battery cartridge:
(1) Do not touch the terminals with any con-
ductive material.
(2) Avoid storing battery cartridge in a con-
tainer with other metal objects such as
nails, coins, etc.
(3) Do not expose battery cartridge to water
or rain.
A battery short can cause a large current
ow, overheating, possible burns and even a
breakdown.
6. Do not store the tool and battery cartridge in
locations where the temperature may reach or
exceed 50 °C (122 °F).
7. Do not incinerate the battery cartridge even if
it is severely damaged or is completely worn
out. The battery cartridge can explode in a re.
8. Be careful not to drop or strike battery.
9. Do not use a damaged battery.
10. The contained lithium-ion batteries are subject
to the Dangerous Goods Legislation require-
ments.
For commercial transports e.g. by third parties,
forwarding agents, special requirement on pack-
aging and labeling must be observed.
For preparation of the item being shipped, consult-
ing an expert for hazardous material is required.
Please also observe possibly more detailed
national regulations.
Tape or mask off open contacts and pack up the
battery in such a manner that it cannot move
around in the packaging.

5ENGLISH
11. Follow your local regulations relating to dis-
posal of battery.
12. Use the batteries only with the products
specied by Makita. Installing the batteries to
non-compliant products may result in a re, exces-
sive heat, explosion, or leak of electrolyte.
SAVE THESE INSTRUCTIONS.
CAUTION: Only use genuine Makita batteries.
Use of non-genuine Makita batteries, or batteries that
have been altered, may result in the battery bursting
causing res, personal injury and damage. It will
also void the Makita warranty for the Makita tool and
charger.
Tips for maintaining maximum
battery life
1. Charge the battery cartridge before completely
discharged. Always stop tool operation and
charge the battery cartridge when you notice
less tool power.
2. Never recharge a fully charged battery car-
tridge. Overcharging shortens the battery
service life.
3. Charge the battery cartridge with room tem-
perature at 10 °C - 40 °C (50 °F - 104 °F). Let
a hot battery cartridge cool down before
charging it.
4. Charge the battery cartridge if you do not use
it for a long period (more than six months).
FUNCTIONAL
DESCRIPTION
CAUTION:
• Always be sure that the tool is switched off and
the battery cartridge is removed before adjust-
ing or checking function on the tool.
Installing or removing battery
cartridge
1
2
3
► 1. Red indicator 2. Button 3. Battery cartridge
CAUTION:
• Always switch off the tool before installing or
removing of the battery cartridge.
• Hold the tool and the battery cartridge rmly
when installing or removing battery car-
tridge. Failure to hold the tool and the battery
cartridge rmly may cause them to slip off your
hands and result in damage to the tool and
battery cartridge and a personal injury.
To remove the battery cartridge, slide it from the tool
while sliding the button on the front of the cartridge.
To install the battery cartridge, align the tongue on the
battery cartridge with the groove in the housing and slip
it into place. Insert it all the way until it locks in place
with a little click. If you can see the red indicator on the
upper side of the button, it is not locked completely.
CAUTION:
• Always install the battery cartridge fully until the
red indicator cannot be seen. If not, it may acci-
dentally fall out of the tool, causing injury to you
or someone around you.
• Do not install the battery cartridge forcibly. If the
cartridge does not slide in easily, it is not being
inserted correctly.

6ENGLISH
Indicating the remaining battery
capacity
Only for battery cartridges with the indicator
1
2
► 1. Indicator lamps 2. Check button
Press the check button on the battery cartridge to indi-
cate the remaining battery capacity. The indicator lamps
light up for a few seconds.
Indicator lamps Remaining
capacity
Lighted Off Blinking
75% to 100%
50% to 75%
25% to 50%
0% to 25%
Charge the
battery.
The battery
may have
malfunctioned.
NOTE: Depending on the conditions of use and the
ambient temperature, the indication may differ slightly
from the actual capacity.
Switch action
A
B
1
► 1. Switch trigger
CAUTION:
• Before inserting the battery cartridge into the
tool, always check to see that the switch trigger
actuates properly and returns to the "OFF"
position when released.
• Change the direction of rotation only when the
tool comes to a complete stop. Changing it
before the tool stops may damage the tool.
The switch is reversible, providing either clockwise or
counterclockwise rotation. To start the tool, simply pull
the lower part (A) of the switch trigger for clockwise or
the upper part (B) for counterclockwise. Release the
switch trigger to stop.
Lighting up the front lamp
1
2
► 1. Lamp 2. Lamp switch
CAUTION:
• Do not look in the light or see the source of light
directly.
Push the upper position of the lamp switch for turning
on the light and the lower position for off.

7ENGLISH
NOTE:
• Use a dry cloth to wipe the dirt off the lens of
lamp. Be careful not to scratch the lens of lamp,
or it may lower the illumination.
• The light is provided with anti excessive dis-
charge circuit. When the lamp does not light up
even after the light switch is turned on, there is
likely to be battery power drop. Try to charge the
battery cartridge.
• Keep the lamp switch in "off" position while not
in need of the light.
ASSEMBLY
CAUTION:
• Always be sure that the tool is switched off and
the battery cartridge is removed before carrying
out any work on the tool.
Installing or removing the bit
11.2 mm
Use only the bit shown in the gure. Do not use any
other bit.
1
2
► 1. Bit 2. Sleeve
To install the bit, pull the sleeve in the direction of the
arrow and insert the bit into the sleeve as far as it will
go. Then release the sleeve to secure the bit.
To remove the bit, pull the sleeve in the direction of the
arrow and pull the bit out rmly.
NOTE:
• If the bit is not inserted deep enough into the
sleeve, the sleeve will not return to its original
position and the bit will not be secured. In this
case, try re-inserting the bit according to the
instructions above.
• After inserting the bit, make sure that it is rmly
secured. If it comes out, do not use it.
Ring
12
3
► 1. Bracket 2. Ring 3. Screws
The hook is convenient for hanging the tool with hoist.
First, place the rope through the ring. Then hang the
tool up to the air with hoist.
CAUTION: Before using the ring, always make
sure that the bracket and ring are secured and not
damaged.
Hook
CAUTION: After installing the hook, make sure
that it is screwed rmly.
1
2
3
► 1. Groove 2. Screw 3. Hook
The hook is convenient for temporarily hanging the tool.
This can be installed on either side of the tool.
To install the hook, insert it into a groove in the tool
housing on either side and then secure it with a screw.
To remove, loosen the screw and then take it out.

8ENGLISH
OPERATION
CAUTION:
• Always insert the battery cartridge all the way
until it locks in place. If you can see the red part
on the upper side of the button, it is not locked
completely. Insert it fully until the red part cannot
be seen. If not, it may accidentally fall out of the
tool, causing injury to you or someone around
you.
Hold the tool rmly. Place the drill bit on the workpiece
or place the socket over the bolt or nut and turn the tool
on. For fastening operation, release the switch trigger
after the proper fastening time.
Drilling in wood
When drilling in wood, the best results are obtained
with wood drills equipped with a guide screw. The guide
screw makes drilling easier by pulling the bit into the
workpiece.
CAUTION:
• Pressing excessively on the tool will not speed
up the drilling. In fact, this excessive pressure
will only serve to damage the tip of your bit,
decrease the tool performance and shorten the
service life of the tool.
• There is a tremendous force exerted on the tool/
bit at the time of hole break through. Hold the
tool rmly and exert care when the bit begins to
break through the workpiece.
• A stuck bit can be removed simply by setting
the reversing switch to reverse rotation in order
to back out. However, the tool may back out
abruptly if you do not hold it rmly.
• Always secure small workpieces in a vise or
similar hold-down device.
• If the tool is operated continuously until the
battery cartridge has discharged, allow the tool
to rest for 15 minutes before proceeding with a
fresh battery.
Fastening torque
The proper fastening torque may differ depending upon
the kind or size of the bolt, the material of the workpiece
to be fastened, etc. The relation between fastening
torque and fastening time is shown in the gures.
100
200
300
01
23
(3060)
(2040)
(1020)
M20 (M20)
M16 (M16)
M12 (M12)
N m
Fastening time(S)
Standard bolt
(kgf cm)
Proper fastening torque
Fastening torque
100
200
300
0123
(3060)
(2040)
(1020)
M16
(M16)
M12 (M12)
N m
Fastening time(S)
High tensile bolt
(kgf cm)
Proper fastening torque
Fastening torque
M14
(M14)

9ENGLISH
NOTE:
• Hold the tool pointed straight at the bolt or nut.
• Excessive fastening torque may damage the
bolt/nut or socket. Before starting your job,
always perform a test operation to determine the
proper fastening time for your bolt or nut.
• If the tool is operated continuously until the
battery cartridge has discharged, allow the tool
to rest for 15 minutes before proceeding with a
fresh battery cartridge.
The fastening torque is affected by a wide variety of
factors including the following. After fastening, always
check the torque with a torque wrench.
1. When the battery cartridge is discharged almost
completely, voltage will drop and the fastening
torque will be reduced.
2. Socket
• Failure to use the correct size socket will
cause a reduction in the fastening torque.
• A worn socket (wear on the hex end or
square end) will cause a reduction in the
fastening torque.
3. Bolt
• Even though the torque coefcient and the
class of bolt are the same, the proper fasten-
ing torque will differ according to the diame-
ter of bolt.
• Even though the diameters of bolts are the
same, the proper fastening torque will differ
according to the torque coefcient, the class
of bolt and the bolt length.
4. The use of the universal joint or the extension
bar somewhat reduces the fastening force of the
impact wrench. Compensate by fastening for a
longer period of time.
5. The manner of holding the tool or the material
of driving position to be fastened will affect the
torque.
6. Operating the tool at low speed will cause a reduc-
tion in the fastening torque.
MAINTENANCE
CAUTION:
• Always be sure that the tool is switched off and
the battery cartridge is removed before attempt-
ing to perform inspection or maintenance.
• Never use gasoline, benzine, thinner, alcohol
or the like. Discoloration, deformation or cracks
may result.
Replacing carbon brushes
1
► 1. Limit mark
Remove and check the carbon brushes regularly.
Replace when they wear down to the limit mark. Keep
the carbon brushes clean and free to slip in the holders.
Both carbon brushes should be replaced at the same
time. Use only identical carbon brushes.
1
2
► 1. Brush holder cap 2. Screwdriver
Use a screwdriver to remove the brush holder caps.
Take out the worn carbon brushes, insert the new ones
and secure the brush holder caps.
To maintain product SAFETY and RELIABILITY, repairs,
any other maintenance or adjustment should be per-
formed by Makita Authorized Service Centers, always
using Makita replacement parts.

10
OPTIONAL
ACCESSORIES
CAUTION:
• These accessories or attachments are recom-
mended for use with your Makita tool specied
in this manual. The use of any other accessories
or attachments might present a risk of injury to
persons. Only use accessory or attachment for
its stated purpose.
If you need any assistance for more details regard-
ing these accessories, ask your local Makita Service
Center.
• Drill bits
• Makita genuine battery and charger
NOTE:
• Some items in the list may be included in the
tool package as standard accessories. They
may differ from country to country.
ENGLISH

11

Makita Corporation
3-11-8, Sumiyoshi-cho,
Anjo, Aichi 446-8502 Japan
www.makita.com
885348A225
EN
20170908