Knowing the Different Types of Drill Bits Can Help You Choose the Right Tool
In its simplest form, a drill is a tool that uses a rotary or cutting motion to create holes. This broad definition encompasses various types of drills, from dental drills to tunnel boring machines. For this article, we’ll focus on the types of drills commonly used in construction and homes.
But before we dive in, let’s go over a few technical definitions. A drill is used to make holes, while drivers use screwdrivers to tighten screws, bolts, and other fasteners. These two applications are what most people think of when they hear the word “drill.” So for our purposes, we’ll group them together.
Drill Driver: One of the Most Common Types of Drills
Both corded and cordless drills have a chuck that opens and closes slightly. Regardless of voltage, battery size, or brand, these tools simply rotate clockwise and counterclockwise. Some cordless drills and drivers also come with a drill clutch, which allows you to set the power transmitted when driving a screw.
When to Use a Cordless Drill
A drill driver is suitable for basic drilling in plastic, wood, and metal. The size of the hole you need to drill determines the power you require. The manual will provide specifications indicating the drill’s capabilities. You can also get some information from the chuck size. A 3/8″ chuck, for example, won’t support larger 1/2″ drills.
Cordless drills are also great for driving fasteners into plastic, wood, metal, concrete, and many other materials. However, some materials may require a pilot hole before driving the fasteners.
Impact Drill
The basic design of a hammer drill or hammer drill driver is similar to that of a power drill. The difference lies in the addition of a hammer mechanism that vibrates the bit back and forth to cut through concrete. This mechanism is activated when the motor spins the bit. Most hammer drills allow you to choose between hammer drill mode, drill-only mode, or drive mode with a clutch. In other words, you can disable the hammer mechanism and use it like any other power drill.
When to Use an Impact Drill
A rotary hammer is the all-purpose tool when it comes to drilling and driving in plastic, wood, metal, and concrete/masonry. Note that most hammer drills are rated for concrete drilling up to 1/4 inch. For concrete drilling, you may also need a vacuum cleaner and a hood to prevent inhaling silica dust and avoid silicosis.
Rotary Hammer (Combination Hammer)
An electric hammer, also known as a combined hammer or combihammer, is the larger counterpart to the power hammer. These concrete drill rigs come in various sizes, ranging from slightly larger than a hammer drill to much larger. They utilize a more powerful hammering/cutting mechanism to deliver greater power than impact drills.
These tools typically have at least two modes: cutting and rotary hammering. Some models only offer the option to swivel, which few professionals use despite its capability to drill through wood and metal.
When to Use a Rotary Hammer
A rotary hammer is ideal for drilling or breaking through concrete, asphalt, stone, brick, and other masonry materials. The larger rotary hammers can handle drilling up to 2 inches in diameter.
Impact Drivers (Hear Us Out!)
While not classified as a true drill type, the impact driver makes our list due to its compatibility with a wide range of hex fittings. The hex chuck on these tools, known as an impact driver, supports spade bits, auger bits, and more. Impact drivers operate using a rotating hammer and anvil mechanism instead of a forward cutting mechanism. As the chuck turns, the hammer strikes the anvil forcefully, generating rotational force significantly greater than that of a standard drill bit.
As mentioned earlier, many drills now come with “impact-ready” 1/4″ hex shanks, allowing you to use an impact driver to drill holes in metal, plastic, or wood. While not as smooth as a regular drill, impact drivers are incredibly effective.
When to Use an Impact Driver
Impact drivers are the go-to tool for professionals in the construction industry when it comes to quickly driving screws. While you can use them to drill holes with the right bit, many professionals pair them with a regular drill to avoid switching bits during work. So, when faced with the choice between a drill and an impact driver, go for both. It can save you a lot of time.
Core Drill
Core drills are less common types of drill bits. They consist of a large motor, sometimes attached to a frame for stability while drilling. These drills use a coring bit, a cylindrical bit that creates a core instead of removing the entire material. Core drills solely rotate; there is no hammering, chipping, or driving mechanism involved.
When to Use a Core Drill
When it comes to drilling large holes in concrete, a core drill is unparalleled. These specialized tools work slowly, but certain tasks require time.
Earth Auger
An earth auger, sometimes referred to as a ground auger, employs AC or gas power to rotate its robust motor. These augers feature an aggressive and broad bit, which tears through the ground and removes dirt more efficiently than a post hole digger or shovel. Recently, cordless augers like the Makita earth auger and the Ryobi 40V brushless auger have emerged, offering the convenience and battery power of cordless tools that were previously limited to gas-powered variants.
When to Use an Earth Auger
Augers excel at moving large amounts of soil. These drills can make your life easier when you need to dig holes in the ground or even in ice. They are ideal for setting up various types of posts, as well as cutting holes for ice fishing.
Keep in mind that while earth and ice drills may appear similar, there are differences. Ice drills typically operate at high RPMs and weigh less than ground drills. Their sharper blades are less prone to tangling, making them well-suited for cutting through ice. On the other hand, ground drills have a steeper blade pitch and are more effective for navigating rock and mud.
Cordless Screwdriver
Although not categorized as a power drill, a cordless screwdriver functions similarly to one. These devices usually feature an inline design rather than the traditional pistol grip and are less powerful than standard cordless drills. Cordless screwdrivers rotate the chuck clockwise or counterclockwise and are primarily used for driving small screws. While they can drill small holes, they are not the ideal tool for the job.
When to Use a Cordless Screwdriver
Power screwdrivers are perfect for driving small and delicate fasteners that don’t require the torque of a standard drill. They work well for tasks such as working in distribution boxes, setting switch panels, and any scenario where a handheld screwdriver can be used.
Drywall Screwdriver (Drywall Screw Gun)
Similar in design to a pistol grip drill, the drywall screwdriver is not technically a drill but a specialized tool for driving and fastening. These tools typically spin at a higher RPM, allowing for speedy and efficient screw fastening. Professional models often come with organized magazines that automatically load screws as you go, significantly speeding up the work process.
When to Use a Drywall Screwdriver
As the name implies, drywall screw guns are perfect for quick installation of drywall panels. Models capable of handling longer screws are also great for deck building.
Wrapping It Up
Are there other types of drills we missed? No matter the job or project, the drill’s origins can be traced back to the simple act of spinning a sharp stone to create a hole in another object. When we look back even just a century, we can see how much drills have improved!