Impact Driver Uses, What It's For & When to Use It

Getting frustrated with fasteners and wondering if there’s a faster, easier way to finish your project? An impact driver might be the missing must-have for your toolkit. This handy guide will cover what an impact driver does, its mechanisms, as well as situations when and when not to use one, so you’ll know if it’s the right fit for your project.

Impact drivers are versatile tools that can be used for a variety of amateur and professional applications, including:

• Driving screws: This is the most common use for an impact driver. The concussive action prevents cam-out (where the driver slips out of the screw head), allowing you to drive screws quickly and efficiently without stripping the head. This is particularly useful when driving long or large screws into hardwoods, metal, concrete, and other dense materials. They can also be used to remove stripped or rusted screws.
• Installing deck boards: Building a deck often involves driving numerous screws into hardwood. An impact driver makes this task significantly easier and faster compared to using a traditional screwdriver, reducing fatigue and improving productivity.
• Assembling furniture: Impact drivers can be used to assemble furniture that requires screws to be driven into wood or metal, be it flat-pack furniture or handcrafting custom pieces.
• Driving lag bolts: Lag bolts are large, heavy-duty screws used for structural applications. An impact driver provides the necessary torque to drive these bolts into wood or concrete with ease.
• Construction and remodelling: Impact drivers are essential tools for construction and remodelling tasks, such as framing, installing subfloors, and fastening sheathing.
• Automotive repairs: Impact drivers can be used to remove stubborn, rusted or stripped bolts from cars and other vehicles.
• Installing flooring: Impact drivers can be used to securely fasten flooring such as hardwood, laminate, or decking.
• Driving fasteners in tight spaces: Impact drivers are ideal for driving fasteners into tight spaces where you cannot use a traditional screwdriver or drill.
• Securing concrete fasteners: With the right bits and attachments, impact drivers can be used to drive concrete fasteners, such as anchors and bolts, into concrete walls or floors.

An impact driver looks almost identical to a standard drill (or impact drill) on the surface. So how does an impact driver work in a way that makes it more powerful than a drill?

A standard drill relies solely on rotational force to drive screws and bolts into hard materials. However, an impact driver combines this rotational force with a concussive hammering action to deliver even stronger blows to the fastener. Here's a breakdown of the process:

1. Motor rotation: The motor within the impact driver rotates the output shaft.
2. Torque build-up: As the motor rotates, it drives a spring-loaded hammer mechanism.
3. Impact action: When the rotational force encounters resistance (like when driving a screw into wood), the spring-loaded hammer is released, delivering a powerful concussive blow to the anvil. This anvil is connected to the output shaft, transferring the impact energy to the fastener.
4. Combined force: The combination of rotational force and concussive blows provides the higher torque needed to drive fasteners quickly and efficiently into dense materials.

This mechanism makes the impact driver ideal for uses involving driving large screws, lag bolts, and other fasteners into dense materials like wood, metal, and even concrete, or if you need to remove stubborn screws that have been stripped or rusted.

While impact drivers are highly versatile and useful tools, there are still a few situations where they are not the ideal tool. Here’s when not to use an impact driver:

• Drilling holes (without a drill bit attachment): Impact drivers are primarily designed for driving fasteners, not drilling holes. While some models can accept drill bits with the appropriate chuck adapter, using an impact driver for drilling without the correct setup can damage the tool or the material. Generally speaking, if you need to drill a hole, use a drill, or an SDS drill for heavy-duty tasks.
• Driving small or delicate screws: Impact drivers can be too powerful for driving small or delicate screws. Their high torque can result in overtightening or stripping of the screws. For these applications, a standard drill or screwdriver with adjustable torque settings is more suitable.
• Precision work or fine threading: Impact drivers are not designed for precision work or fine threading, as the concussive action makes it difficult to control the precise depth and tightness of the fastener. If you need to make precise adjustments or create fine threads, use a screwdriver or drill.
• Working with soft or brittle materials: Impact drivers can damage soft or brittle materials, such as plastic or drywall. For these materials, a drill with adjustable clutch settings is a better choice.
• Working with smaller fasteners (e.g. small screws or bolts): Impact drivers can be too powerful for driving small screws or bolts, and can easily strip or damage the fasteners.
• When a clean, controlled torque is needed: Impact drivers deliver a high amount of torque, which can be difficult to control. If you need to apply a precise amount of torque, such as when assembling delicate electronics or machinery, use a torque wrench to achieve more precise control.
• In applications requiring a clutch setting: Impact drivers generally do not have an adjustable clutch setting, so they are not suitable for applications that require a controlled amount of torque.
• Tightening or loosening fasteners that need exact torque: Impact drivers are not designed for tightening or loosening fasteners that require exact torque. This may be relevant in applications for automotive or mechanical work, where precision is key.
• Working with delicate electronics: Impact drivers can damage delicate electronic components.
• Working with a non-impact-rated bit: Always use impact-rated bits with your impact driver. Standard drill bits are not designed to withstand the high torque and impact forces and can break or shatter during use.

Impact drivers and drills are both power tools that can be used to drive screws and bolts. However, there are some key differences between how impact drills and impact drivers work:

• Function: Impact drivers are designed to deliver a high amount of torque, which makes them ideal for driving screws and bolts into hard materials. Drills are designed to rotate at a high speed, which makes them ideal for drilling holes.
• Mechanism: Impact drivers use a hammering action to drive screws and bolts, while drills use a rotating action.
• Torque: Impact drivers deliver much more torque than drills. This makes them ideal for driving screws and bolts into hard materials that are difficult to drill with a traditional drill.
• Speed: Drills rotate at a much higher speed than impact drivers. This makes them ideal for drilling holes, but it can also damage screws and bolts if used incorrectly.
• Control: Impact drivers are typically less controllable than drills. This is because the hammering action can make it difficult to control the depth and speed of the screw or bolt being driven.
• Size and design: Impact drivers are typically larger and heavier than drills. This is because they have a more powerful motor and a larger gearbox.
• Bits: Impact drivers use special impact driver bits, which are designed to withstand the high torque generated by the tool. Drills can use standard drill bits.
• Applications: Impact drivers are ideal for driving screws and bolts into hard materials, such as wood, metal, and concrete. Drills are ideal for drilling holes in a variety of materials.
• Noise: Impact drivers are typically louder than drills. This is because of the hammering action that they use.
• Weight: Impact drivers are typically heavier than drills. This is because they have a more powerful motor and a larger gearbox.

Impact drivers and impact wrenches are both power tools that use a hammering action to drive fasteners. However, there are some key differences between the two tools:

• Function: Impact drivers are primarily used for driving screws and bolts, while impact wrenches are primarily used for tightening and loosening nuts and bolts.
• Mechanism: Impact drivers use a rotating anvil to drive screws and bolts, while impact wrenches use a rotating hammer to tighten and loosen nuts and bolts.
• Torque: Impact wrenches typically deliver more torque than impact drivers. This makes them ideal for tightening and loosening large nuts and bolts.
• Size and design: Impact wrenches are typically larger and heavier than impact drivers. This is because they have a more powerful motor and a larger gearbox.
• Power source: Impact wrenches can be powered by either air or electricity. Impact drivers are typically powered by batteries.
• Applications: Impact wrenches are commonly used in automotive repair, construction, and industrial applications. Impact drivers are more commonly used for DIY projects and home repairs.
• Type of fasteners: Impact wrenches are typically used with nuts and bolts, while impact drivers are typically used with screws.
• Speed: Impact wrenches typically rotate at a higher speed than impact drivers. This makes them ideal for quickly tightening and loosening nuts and bolts.
• Weight: Impact wrenches are typically heavier than impact drivers. This is because they have a more powerful motor and a larger gearbox.
• Control: Impact wrenches typically have a better control of torque than impact drivers. This is because they have a clutch that can be adjusted to control the amount of torque applied to the fastener.

Impact drivers are powerful tools that can be dangerous if used incorrectly. Here are some safety tips to follow when using an impact driver:

• Wear safety goggles and ear protection: Always wear safety goggles to protect your eyes from flying debris and ear protection to reduce the risk of hearing damage from the loud noise generated by the impact driver.
• Ensure the correct bit is securely attached: Before you start, double-check that the correct bit is securely attached to the impact driver. A loose bit can become a projectile during operation.
• Use the right size and type of screw or fastener: Using the wrong type or size of screw or fastener can damage the tool, the fastener, or the material you're working with.
• Maintain a firm grip on the tool: Always hold the impact driver with a firm grip to maintain control and prevent it from slipping or kicking back during operation.
• Keep hands and other body parts away from the working area: Keep your hands and other body parts clear of the rotating bit and the fastener being driven to avoid potential injuries.
• Always work in a well-lit area: Adequate lighting ensures clear visibility, reducing the risk of accidents.
• Avoid using excessive force: Let the impact driver do the work. Applying excessive force can damage the tool, the fastener, or the material.
• Keep the tool clean and well-maintained: Regularly clean and maintain your impact driver according to the manufacturer's instructions. This will ensure its longevity and safe operation.
• Use a stable work surface or clamp materials securely: Always work on a stable surface or securely clamp the materials you're working with to prevent movement and potential injury.
• Disconnect the battery or power source when changing bits or making adjustments: This prevents accidental starting of the tool while you're making adjustments or changing bits.

By following these safety precautions, you can minimise the risk of accidents and ensure a safe and productive experience when using your impact driver.

Understanding the differences between impact drivers versus impact wrenches versus impact drills is crucial for selecting the right tool for your specific needs.

If you need a versatile tool for driving screws and bolts into a variety of materials, an impact driver is a great choice. If you need to tighten or loosen large nuts and bolts, an impact wrench is the better option. And if you primarily need to drill holes, a drill is the most suitable tool.

Consider the type of fastener you'll be working with, the material you'll be driving it into, and the level of torque required to determine if it’s the right tool for your project, or if another tool from RS’ vast catalogue might be a better fit. RS Australia offers a wide selection of impact drivers, impact wrenches, and drills from leading brands, amongst other tools for amateur DIY enthusiasts and professional constructors alike. Browse our range online to find the perfect tool for your next project.