An impact driver looks a lot like a standard power drill; however, it combines impact action with drill rotation to provide greater force for difficult jobs. You will be pleasantly surprised to see just how much torque a small-sized impact driver can generate, making many heavy-duty jobs (such as deck building) much easier and faster to complete.
If you are familiar with impact drivers, you can go directly to the Buying Guide which shows reviews and ratings of the best cordless electric impact drivers to help you Get the Right Tool.
What Is An Impact Driver?
Plenty of people already have a cordless power drill in their toolbox; however, a new and improved tool, the impact driver, has captured the attention of do-it-yourself craftsmen as well as commercial contractors.
The impact driver is a versatile power tool that produces torque far greater than standard power drill. This is achieved by adding a hammer-like impact to rotational motion. Therefore, you can use this tool for driving heavy screws or tightening large nuts and bolts. Also, you can reverse the direction of rotation to loosen nuts, bolts, and large screws that are over-tightened or corrosively "frozen."
A well-designed impact driver can easily drive large or long screws that would stall the best conventional drills; and it can drive them rapidly. For example, an impact driver is ideal for building wood decks, or installing plywood subfloors. Therefore, if you are planning projects that require driving a lot of screws, nuts, and bolts, you should have an impact driver in your toolbox.
For simpler projects, you may want to keep your old drill. An important distinction is that impact drivers have a collet that is designed to accept hex-shanked driver bits, instead of the keyless chuck found on most standard drills that use cylindrical bits. This eliminates bit slippage that would otherwise occur due to the impact action of the driver. However, hole-drilling accessories and drill chucks are now available for use in impact drivers.
Most cordless impact drivers are smaller and weigh considerably less than comparable cordless drills. In addition, impact drivers generate less reaction force on your arm and wrist. Therefore, they are easier to handle and can be used in tight corners or constricted spaces.
Impact Driver Types
A variety of impact driver types are available in the market. They can be grouped into three main categories: manual, electric-powered, and pneumatic-powered. The following overview of the impact driver concept can help you figure out the type of impact driver that would work best for your specific needs -- so you can Get the Right Tool.
Manual Impact Driver
Manual impact drivers need the most physical exertion by the user but they are small and do not require power sources. You insert a screwdriver bit into the open end of the driver. The screwdriver bit goes into the screw you want to drive, and you hold the impact driver with one hand.
With the other hand, you use a rubber mallet to strike the upper part of the impact driver. This hammering action increases the force that is applied to the screw and drives it in much quicker than you could with a manual screwdriver.
This type is not common anymore because of improvements in the tool industry coupled with the increased production and ease of use of powered impact drivers. Manual impact drivers are, of course, less expensive than other types.
Electric Impact Driver
Electric impact drivers come in two main styles: cordless and corded. Both these types rely on electric power to work a small internal motor connected to a geared shaft. The internal motor turns the shaft to drive the bolts or screws and also exerts a force on the shaft similar to a hammer to offer more driving power. The electric motor does the work for you.
Cordless electric impact drivers have undergone a lot of improvement and are capable of providing just as much power as their corded counterparts. Cordless electric impact drivers are used heavily in construction work and home repair jobs.
In most cases, cordless electric impact drivers have power levels ranging from 12 volts to 20 volts. These tools are extremely simple to operate and are a very useful addition to your garage or toolbox.
The Buying Guide shows reviews of some of the best cordless impact drivers for your consideration.
Pneumatic Impact Driver/Wrench
A pneumatic impact driver is powered by compressed air and makes the loud whirring sound usually heard at tire and automobile repair shops. The pneumatic tool is not suitable for driving screws; rather it is used to install or remove heavy-duty bolts and nuts.
Pneumatic impact drivers are common in major construction projects and automotive repair shops. They require heavy-duty air compressors and hoses to function. Because of their extreme power and the need for expensive air compressors, most homeowners do not use pneumatic impact drivers. However, buying a pneumatic impact driver will make your life simpler if you are into car repair or restoration.
How Does An Impact Driver Work?
The Impact driver works by exerting a sudden hammer-like shock combined with a rotational force that, for example, drives a screw into a wall. Impact drivers also produce results comparable to a hammer drill for jobs like making a clean pilot hole in a wood post prior to driving a large lag screw.
Most impact drivers have toughened metal adapters and robust screwdriver bits that are especially useful when you are working with a large quantity of self-tapping screws. The shear impact combined with rotational force generated by the impact driver rapidly hammers the screws into place.
When used properly, the size and shape of the impact driver lets you leverage extra grip and force to loosen almost any hard-to-turn nut or bolt. Repetitive short bursts of force eventually produce some twisting movement (tightening or loosening) of the "frozen" fastener. An impact driver can certainly be used effectively to disassemble and assemble a wide variety of professional or do-it-yourself projects.
Cordless electric impact drivers can deliver up to three times more torque (turning force) than many standard electric drills. In a recent tool test, a single 18-volt cordless electric impact driver successfully drove an astounding 138 three-inch lag screws in just one battery charge.
Despite the brute strength of the tool, the impact driver is typically comfortable and easy to use as it's concussive actions transfer most of the high-energy torque straight to the screws, instead of your forearm or wrist.
Although many impact drivers do not have any slip clutch, their concussive action lets you drive nuts and screws with great precision and control.
Impact Driver Applications
The impact driver is very versatile and can be used for many indoor and outdoor projects. For example, it is an excellent option for securing drywall when you are building a new wall or remodeling a house.
An impact driver is also suitable for many woodworking projects, such as making screwed joints in soft or thin wood furniture projects. In contrast, in a hardwood project the impact driver can be used to drill pilot holes to avoid splitting the wood or damaging the screws.
Below are some additional common uses of impact drivers.
Removal Of Brake Drum
Cordless electric impact drivers, equipped with sturdy screwdriver bits, are often used to easily remove the two lock screws found on the rear brake drum of many cars. However, pneumatic-powered impact wrenches are commonly used for heavier duty automotive work.
Drive Self-Tapping Screws
The hammer-like force coupled with the rotational speed of an electric impact driver makes the tool perfect for driving self-tapping screws into sheets of metal. For example, the rapid and precise capabilities of the impact driver are ideal for assembling a backyard metal shed or a fastening down a galvanized metal roof.
Break Loose Rusted Nuts And Screws
The combination of hammering action and extra torque delivered by both manual and powered impact drivers is perfect for breaking loose rusted bolts and nuts. Also, bolts and nuts that have been over-tightened can usually be broken loose with an impact driver.
What Are Impact Driver Bits?
Impact driver bits are different from regular drill bits. They have more torsional strength and a breaking angle which provides cushioning and flexibility under impact, considerably increasing their useful life. This is achieved by the hex-shaped shank coupled with a modified tip that shifts excess pressure away from the tip to a stronger torsional zone. Impact driver bits also have the following distinct features:
Impact Driver Vs. Drill
Although drills and impact drivers look quite similar, there are important differences between the two. An impact driver has a much greater rotational torque than most drills; it also has a quick-paced rotational hammering action that drills do not have. This drives a fastener quicker and better, and helps keep the tip of the bit in place.
Most drills are for lightweight work. However, many tasks need plenty of brute force, which is where an impact driver can be one of the most effective and handy tools you will own.
For example, the impact driver design is suitable for building shop furniture, installing cabinets, building theater sets, swing set construction, deck building, and similar heavy-duty jobs.
Keep in mind that an impact driver cannot always replace a drill. Impact drivers deliver extreme torque that usually requires the use of specialized hex chuck bits, which keeps the shank from spinning under extreme load. Drills are ideal for easier jobs such as drilling holes for putting up pictures or putting together small structures like entertainment stands.
You will not need to worry about electrical cords getting tangled if you choose cordless electric power tools. Many models of impact drivers as well as drills are cordless and run on rechargeable batteries. Power drills typically require larger and heavier batteries to get useful run times, but impact drivers are more compact and lightweight, which makes them very easy to carry around.
Another great appeal of an impact driver is you do not need to exert much manual force on the tool while you are working. You can easily use it with only one hand for driving or drilling. The pressure required comes from the impact driver itself; all you need to do is hold it in place. Although an impact driver generates plenty of torque, using the tool will not put extra strain on the wrists.
Impact Driver Vs. Impact Wrench
Impact wrenches tend to be bulkier, heavier and more powerful (more torque) compared to impact drivers.
An impact wrench has a square drive (usually ½ inch) with sockets to loosen or tighten nuts and bolts; in contrast, impact drivers use a hex drive (typically ¼ inch) and are mainly used to drive in screws. However, many ¼ inch impact drivers can be easily converted to a ½ inch square drive using an adapter accessory.
Some of the most powerful impact drivers can generate up to 2,300 ft-lbs of torque. In contrast, a behemoth impact wrench can deliver more than six times this amount. So, unless you are planning to renovate a semi-truck in the driveway, this excess power is of little use for many household jobs.
An impact driver is great for situations where regular drills do not have sufficient power; however, an impact wrench is just overkill for many general-purpose jobs, where a drill is not quite powerful enough but an impact driver would be perfect.
Impact Driver Manufacturers
The top impact driver brands offer products that are very versatile, extremely durable, and more importantly, sufficiently powerful to complete the job! All of the impact driver brands on our list have been continuously improving their craft in this industry for several decades. Some of their best products are reviewed for your consideration in the Buying Guide .
As a result, they have a long list of satisfied customers. These manufacturers have risen to the top in a very competitive industry by performing well and being reliable for many years.
DeWalt is a popular American brand of hand tools and power tools for the manufacturing, construction and woodworking industries. Raymond E. DeWalt, inventor of the radial arm saw, founded the company in 1923. The business grew rapidly and was re-incorporated and reorganized as DeWalt Inc in 1947.
Apart from impact drivers, the company makes an extensive line of power tools and hand tools such as axes, hammers, hand saws, pry bars, wood chisels, wrench sets, pliers, ratchets, and snips.
Makita is a leading brand of impact drivers and other power tools, both corded and cordless. The company was incorporated in 1915 to sell and repair electric motors. At present, it is an international brand with presence in more than forty countries. Makita prides itself as an innovative leader, producing the best products at ten plants that operate in eight countries.
The durability and quality of Makita products are heavily driven by its strong research and development capabilities, earning the company the trust of household and professional users around the world.
The company also manufactures drills, saws, grinders, heat guns, demolition hammers and many other useful tools.
Ryobi is a Japanese company that manufactures components for the electronics, automobile, and telecommunications industries. The brand is also popular for its power tools, printing equipment, and builder's hardware.
Ryobi operates twelve manufacturing plants in six countries. The company makes cordless drills, impact drivers, hammer drills and saws.
Milwaukee is a brand of Techtronic Industries, the parent company of AEG, Hoover, Ryobi, Dirt Devil and Vax. The company produces both cordless and corded impact drivers and other power tools; plus hand tools such as pliers, saws, screwdrivers, knives, trims, and tool combo kits.
Milwaukee instruments are available worldwide, and include leveling items, digital meters, lighting testers, recognition pieces, thermal imaging items, temperature meters, and clipping, cutting and drilling instruments.
Bosch Power Tools is a global market leader in the power tools industry. Their key success factors include dedicated associates and partners and an unrelenting pace of innovation.
Every year, the company launches over hundred new power tools in the global market. The company makes cordless combo kits and power tools, impact drivers, drills, planers, saws, and sanders.
Taking proper care of your impact driver can help it last much longer and ensure it works smoothly and safely. The following are a few maintenance tips that will keep your impact driver running efficiently:
This article has provided an overview of what an impact driver is, the various types, how they work, and described some common uses of impact drivers.
We have looked at some leading impact driver manufacturers and provided tips on how you can maintain your impact driver to ensure safe and smooth operation.
We believe that a cordless electric impact driver is right tool for many professional and do-it-yourself jobs. Our Buying Guide summarizes some of the most versatile and useful impact drivers we have reviewed, so you can compare and Get the Right Tool for your job!