An impact driver is a powerful tool that can make driving screws and other fasteners a breeze. While it looks similar to a cordless drill, an impact driver has some key differences that set it apart. This compact powerhouse delivers more torque and driving force than a standard drill, making it ideal for heavy-duty fastening jobs. In the video above, This Old House contributor Mark Clement explains the unique features and advantages of impact drivers.
What Is an Impact Driver?
An impact driver is a specialized power tool designed to drive screws, bolts, and other fasteners with high torque and rotational force. Unlike a standard drill that relies on constant rotational force, an impact driver uses a combination of rotation and concussive force to drive fasteners quickly and efficiently.
An impact driver’s internal impact mechanism is what makes it unique. This mechanism consists of an anvil that engages when the tool encounters resistance. As Clement explains in the video, the anvil essentially “smashes” the corners of the bit, delivering thousands of small rotational impacts per minute. This action creates a massive amount of force, allowing the impact driver to power through tough materials and drive large fasteners with ease.
Impact Driver Features
Impact drivers have several distinguishing features that set them apart from standard drills:
- Compact size: Impact drivers are typically smaller and lighter than cordless drills, making them easier to maneuver in tight spaces.
- High torque output: The impact mechanism allows these tools to deliver significantly more torque than a standard drill.
- Hex shank chuck: Impact drivers use a 1/4-inch hex shank chuck, which only accepts bits with a hexagonal shaft.
- Noise level: Due to the impact mechanism, these tools tend to be louder than standard drills during operation.
Impact Driver vs. Cordless Drill
While both impact drivers and cordless drills are designed for fastening tasks, they have distinct differences that make them suitable for different applications.
Versatility
Cordless drills are more versatile tools, capable of drilling holes and driving fasteners. They can accept a wide range of bit types, including round shank bits, making them a good choice for various tasks around the home and workshop.
Impact drivers, on the other hand, are primarily designed for driving fasteners. They excel at this task but are limited to hex shank bits, which reduces their versatility compared to cordless drills.
Power and Torque
Impact drivers deliver significantly more torque than cordless drills, especially when driving large fasteners or working with dense materials. This makes them ideal for tasks such as driving long screws into lumber or installing lag bolts.
Cordless drills typically have less torque but offer more control and precision, making them better suited for delicate tasks or when drilling holes in various materials.
Size and Weight
As Clement points out in the video, impact drivers are generally more compact and lighter than cordless drills. This makes them easier to handle for extended periods and allows for better access in tight spaces.
When To Use an Impact Driver
Impact drivers excel in situations that require high torque and driving power. Here are some common scenarios where an impact driver is the tool of choice:
- Automotive repairs: Impact drivers come in handy when handling automotive repairs, especially when dealing with stubborn or rusted bolts.
- Cabinet installation: An impact driver makes installing hinge screws and hardware for cabinetry in kitchens and bathrooms much quicker.
- Driving into dense materials: When working with hardwoods or other dense materials, an impact driver can power through where a standard drill might struggle.
- Driving long screws: If you’re working with deck boards, framing, or other projects that require long fasteners, an impact driver can drive screws quickly and efficiently.
- Furniture assembly: The high torque makes it easier to assemble flat-pack furniture quickly without stripping the screws.
- Installing concrete anchors: Once the pilot hole is drilled, an impact driver can firmly secure concrete anchors, saving time and enhancing efficiency.
- Installing lag bolts: An impact driver’s high torque makes it ideal for driving large lag bolts into wood or other materials.
- Loosening stubborn fasteners: The impact mechanism can help break loose rusted or overtightened bolts and screws.
- Repetitive fastening tasks: For projects that involve driving many screws, such as building a deck or installing drywall, an impact driver can significantly speed up the process.
Choosing the Right Impact Driver
When selecting an impact driver, consider the following factors to ensure you get the right tool for your needs:
- Battery life: Consider the battery capacity and whether it’s compatible with other tools you own.
- Brand reputation: Opt for a reputable brand known for producing quality power tools.
- Ergonomics: Choose a tool that feels comfortable in your hand and is well-balanced for extended use.
- Torque output: Look for a tool with sufficient torque for your intended applications.
- Voltage: Higher voltage tools generally offer more power but may be heavier and more expensive.
Safety Considerations
When using an impact driver, keep these safety tips in mind:
- Use hearing protection, especially during extended use, due to the tool’s high noise level.
- Wear eye protection to guard against flying debris.
- Ensure the bit is securely locked in the chuck before operation.
- Be cautious of over-tightening fasteners, which can strip threads or damage materials.
- Maintain a firm grip on the tool to control it during high-torque applications.
