CORDLESS IMPACT DRIVER:
A New Era in Cordless Screw Gun
Technology
Will Lazration
3/16/2010
AUDIENCE and SCOPE
The purpose of this article is to inform contractors about a new type of cordless screw gun called
an impact driver and how this innovative tool can save them both time and money. A cordless
screw gun is a necessity for any successful contractor, therefore they already know their
importance to their line of work, but many don’t know how this new impact driver would be
even more beneficial to them. An article such as this would be found in any magazine that deals
with the construction industry or any home improvement magazine.
INTODUCTION
A cordless impact driver is a type of cordless screw gun that combines
the rotating action from a regular screw gun and the hammering action
from a hammer drill to drive screws faster and more efficiently. This
efficiency correlates into longer battery life, a problem with
conventional cordless screw guns. Until recently, the technology to
combine the conventional screw gun and the hammer drill into one
small, lightweight, portable unit was unavailable. Through the efforts of
major tool manufacturers, such as DeWALT, the impact driver was
created (see figure 1).
Figure 1: DeWALT 18V Cordless
Impact Driver
HOW AN IMPACT DRIVER WORKS
HAMMER & ANVIL SYSTEM
The key design feature of a cordless impact driver is the
hammer and anvil system as shown in figure 2 to the left
that generates extra torque. Unlike the conventional
hammer drill where the hammer moves in and out, the
hammer and anvil system in an impact driver is designed
to stay put. To create the “hammering motion”, the
hammer attached to a rotating electric motor rapidly
pounds the anvil, which is attached to the screw bit.
This motion creates a distinctive sound, which gives the
drill its name. The typical cordless impact driver
hammer and anvil system generates up 3,000 blows per
minutes to the screw bit.
Figure 2: BOSCH 12V Impact Hammer and
Anvil System
RECHARGEABLE BATTERY
Just like its counterpart the cordless screw gun, the
cordless impact driver takes advantage of rechargeable
batteries (see figure 3). However batteries used into
today’s impact drivers are far superior the rechargeable
batteries of the past Today’s batteries use Lithium Ion
technology which allows them to stay charged for over
two times the amount when compared to the
conventional cordless drill batteries (see figure 4).
Figure 3: Makita 18V Lithium Ion Battery
An advantage of rechargeable batteries is that
they come in a variety of sizes that include:
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Figure 4: Makita 18V Lithium Ion Battery vs.
Conventional Battery
9.6V
12V
14.4V
18V
36V
Each battery size correlates to the impact
driver’s power. This translates into a wide
variety of impact drivers to meet the demands of
even the toughest jobs.
ADVANTAGES of a CORDLESS IMPACT DRIVER
There are many advantages of using a cordless impact driver compared to a conventional
cordless drill or a hammer drill. Some of the advantages include:
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The torque created from the hammer & anvil system is transferred throughout the drill
and not into the hand of the operator. A conventional hammer drill sends vibrations all
the way up the arm of the operator.
The added torque allows the driver to driver screws faster than conventional screw guns.
It also take the torque out of operators hands. In conventional screw guns the max torque
than can be applied is equal to the strenth of the operator.
Because it drives screws faster and more efficiently, productivity rates will increase.
It can drive longer screws into harder material with ease, without stripping the head off
the screw
The hammer and anvil don’t require any additional power to create the additional torque.
This means the rechargeable battery lasts just as long, and less time is spent re-charging
batteries.
Can loosen rusty bolts with ease
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It weighs on average 3.5 lbs for an 18V unit. This lightweight
enables the operator to work longer without worrying about
fatigue.
It employs a quick release chuck system that uses screw bits like
the one shown in figure 5. This allows for faster bit changes, and
eliminates slip. Conventional drills slip if the chuck isn’t tight
enough on the bit.
Small compact design enables it to be used in places that
conventional cordless drills cannot fit into.
Figure 5: Quick Connect Screw Bit
TYPICAL USES FOR a CORDLESS IMPACT DRIVER
TIGHTENING LAG BOLTS
Lag bolts are used frequently in deck and stair construction
due to the amount of weight they can support. Because lag
bolts are long and require large amounts of torque to install
(see figure 6), a cordless impact driver is a perfect tool for
the job.
Figure 6: Tightening a Lag Bolt with a
Cordless Impact Driver
BUILDING DECKS
Figure 7: Installing Composite Decking
with a Cordless Impact Driver
Construction of the average size deck requires over twenty
five pounds of screws. The majority of the screws are
required to screw the decking boards down. In today’s
society, composite decking boards are used (see figure 7).
The problem with composite is that it’s extremely hard, and
can drain batteries of conventional screw guns in minutes.
The cordless impact driver is the ideal tool for the job. The
hardness of the composite is no match for it power, and it
creates that power without sacrificing battery life.
METAL STUD FRAMING
Framing in commercial building construction is made from
cold-rolled metal studs, not wood like in residential
construction. Nails cannot be used in this application;
therefore small “pan head” screws are used to hold the
components together (see figure 8). In order to be
productive a carpenter needs to have a screw gun that meets
the torque demands of driving a screw into metal. This is the
perfect job for a cordless impact driver.
Figure 8: Metal Framing with a Cordless
Impact Driver
OTHER USES
Figure 9: Drilling Holes with a Cordless
Impact Driver
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Installing ductwork
Drilling holes (see figure 9)
Install cabinets
Assembling Furniture
Hanging Shelves
Hanging Doors
Anything that you would use a conventional cordless
drill for
TOP CORDLESS IMPACT DRIVER MANUFACTURERS
There are numerous tool manufacturers who make cordless impact guns; however five manufacturers
that compromise the majority are Makita, DeWALT, Hitachi, Milwaukee, and Bosch. Examples of an 18 V
model for each manufacturer are listed below.
MAKITA
Hex Shank
No Load Speed
Impacts Per Minute
Maximum Torque
Battery
Overall Length
Net Weight
1/4"
0-2600 RPM
0-3400 IPM
1420 in-lbs
18V LXT Lithium Ion
5 1/2"
3.3 lbs
Figure 10: Makita BTD144
DEWALT
Hex Shank
No Load Speed
Impacts Per Minute
Maximum Torque
Battery
Overall Length
Net Weight
Figure 11: DeWALT DC827KL
1/4"
0-2400 RPM
0-2700 IPM
1,111 in-lbs
18V Lithium Ion
5 3/4"
3.7 lbs
HITACHI
Hex Shank
No Load Speed
Impacts Per Minute
Maximum Torque
Battery
Overall Length
Net Weight
1/4"
0-2600 RPM
0-3200 IPM
1,111 in-lbs
18V Lithium Ion
6 37/64"
3.5 lbs
Figure 12: HITACHI WH18DL
MILWAUKEE
Hex Shank
No Load Speed
Impacts Per Minute
Maximum Torque
Battery
Overall Length
Net Weight
1/4"
0-2600 RPM
0-3200 IPM
1,400 in-lbs
18V Lithium Ion
5 3/4"
3.2 lbs
Figure 13: Milwaukee M18 2650-
BOSCH
Hex Shank
No Load Speed
Impacts Per Minute
Maximum Torque
Battery
Overall Length
Net Weight
Figure 14: Bosch 26618-21
1/4"
0-2800 RPM
0-3200 IPM
1,500 in-lbs
18V Lithium Ion
5 3/4"
3.2 lbs
CONCLUSION
There is no question that power tools have come a long way since the since the invention of the
first portable electric drill by Black & Decker in 1917. (1) Today’s power tools are a staple of
modern technology. Incorporating technology such as Lithium Ion rechargeable batteries into
tools is something Black & Decker never dreamed of in 1917. One of these tools, the cordless
impact driver, is paving the way for a new era in power tool technology. Its innovative hammer
and anvil system generates tremendous amounts of torque required to drive screws into even the
hardest material. Along with its lightweight, comfortable design, it is the must-have cordless
screw gun for any contractor’s inventory of tools. Because the impact driver is so efficient in
turning electrical energy into work, battery life is not sacrificed when using it. The innovative
quick release chuck system allows for quick change of screw bits and drill bits. The number of
uses for this tool is endless. All of this innovative technology allows the operator to be more
efficient, and in today’s society where time is money, will add up to a substantial cost saving for
any contractor.
(1) Taken from http://en.wikipedia.org/wiki/Black_&_Decker on 2/27/2010
Works Cited
www.boschtools.com
www.dewalt.com
http://en.wikipedia.org/wiki/Black_&_Decker
Figure 1: http://www.cordlessimpactdriverreviews.com/How-A-Cordless-Impact-Driver-Works
Figure 2: http://g-ecx.images-amazon.com/images/G/01/th/content_26/Q3_2009/bosch-B001C4AQVG-1-lg.jpg
Figure 3: http://www.makita.com/en-us/Assets/Images/Accessories/cordless/batteries/1L.jpg
Figure 4 & 10: http://www.makita.com/en-us/Modules/Tools/ToolDetails.aspx?ID=316370
Figure 5: http://ecx.images-amazon.com/images/I/41BH26R41SL.jpg
Figure 6: http://www.coptool.com/images/25618.jpg
Figure 7: http://www.hammerzone.com/archives/decks/misc/skirting/xdexpg28.jpg
Figure 8: http://www.fleetmag.com/images/article/1223324105623__Milwaukee_HexImpactDriver_0.jpg
Figure 9 & 14: http://www.boschtools.com/Products/Tools/Pages/BoschProductDetail.aspx?pid=26618-01
Figure 11: http://dewalt.com/tools/cordless-impact-driverswrenches-drivers--wrenches-dc827kl.aspx
Figure 12:http://www.hitachipowertools.com/store_item.php?iID=578&arrPath=1,2,20,p578,&tab=2
Figure13:
http://www.milwaukeetool.com/ProductDetail.aspx?ProductId=265021&CategoryName=SC%3a+Impact+Drivers