Last Updated on August 28, 2022 by Barry Gray
Thinking of getting an impact wrench or an impact driver? Both of these tools are designed to tackle tough fastening tasks, but they have different uses.
An impact wrench is specifically designed for jobs that require a high level of torque output in a compact tool. They’re perfect for tightening bolts with little clearance or working in tight spaces where a normal socket won’t fit.
An impact driver, on the other hand, is great for fastening large bolts or screws because it has the ability to provide more continuous torque at slower speeds. To help you decide which one is right for you, we’ve outlined the pros and cons of each tool and broken down their key features to help you find the best impact wrench or impact driver for your needs.
Impact Wrench – Percussive Torque
An impact wrench is a tool that uses an external power source to generate percussive torque, rather than rotational force. Sometimes they are air-powered, battery-powered, or powered by corded electricity.
Impact wrenches work differently than other manual or electric tools that apply torque through the turning motion of a motor or a rotating shaft. Impact wrenches use a rotating hammer or rotor to create a quick, sudden force that’s applied to the bolt via a short, stubby impact socket.
The impact socket has a flared-out section near the tip that gives it a larger surface area to apply force to the bolt head. This sudden burst of force is similar to the action of a jackhammer and is responsible for the tool’s name. It’s helpful to think of an impact wrench as a power tool that uses the force of a small hammer to increase its speed and efficiency.
Impact Driver – Continuous Rotational Energy
While an impact wrench uses a sudden burst of force to generate torque, an impact driver uses continuous rotational energy. This makes the impact driver a great choice for larger jobs and projects where you need to apply more continuous energy to a screw or bolt.
Impact drivers use both a motor and a rotating hammer to create quick oscillations while the driver bit rotates in place. The hammer inside the tool has a large surface area that creates a quick vibration when it hits the end of the driver bit.
These vibrations are sent down the shaft of the driver and through the bit, where they cause the screw or bolt on the other end to rotate with greater force. Impact drivers are designed for driving fasteners into a variety of materials, but they’re generally not as strong as impact wrenches when it comes to tightening bolts.
Power Source
Impact drivers and impact wrenches both use external power sources to generate their torque. While only impact wrenches can use air, both tools can use electricity supplied by either a cord or a battery. Batteries are becoming more popular, but each of these power sources has its uses.
Impact wrenches can be powered by an air compressor, a compressed CO2 cartridge, or electricity supplied by either a cable or a battery. Pneumatic impact wrenches are typically more powerful, and they’re usually what mechanics and other professionals use.
Air compressors are large and difficult to move around, and the tube leading from the impact wrench to the compressor can have issues like limited range and kinks in the line. On the other hand, CO2 cartridges can run out quickly, although they do allow for much greater mobility.
Electrical impact drivers are typically weaker than those that rely on pneumatics. However, they’re cheaper to operate and more beginner-friendly for people who may not already have an air compressor of their own.
Unlike impact wrenches, impact drivers can’t use compressed air as a power source. Instead, they use electricity supplied by batteries or cables, although batteries are much more popular.
Impact wrenches use an external power source to generate high levels of torque. This can either come in the form of an air compressor, a compressed CO2 cartridge, or electricity supplied by either a cable or a battery.
Torque
One of the most important factors to consider between impact wrenches and impact drivers is torque. They’re both high-torque tools used for quickly applying force to objects that are difficult to turn, like large bolts and nuts.
The most powerful impact drivers can deliver more torque than the smallest impact wrenches. For these especially powerful impact drivers, look for the 18V and 20V models. But when comparing average tools to one another impact wrenches come out as clear leaders.
Impact drivers can deliver up to 2,000 inch-pounds (in-lbs) of torque. Any impact driver that can deliver above 1,600 in-lbs is a great choice for professional use, although impact drivers below that can still be helpful for amateurs and hobbyists.
The smallest impact wrenches deliver 1,200 in-lbs of torque, already close to a professional level. But the most powerful impact wrenches can deliver above 12,000 in-lbs, which is more than five times what the best impact drivers can offer.
Speed
While impact wrenches are the clear leaders for torque, this dynamic flips for speed. Impact drivers can rotate much more quickly than impact wrenches, despite delivering less rotational energy.
Impact drivers can reach up to 3,600 RPM with the best models. Of course, that’s only true for impact drivers that use cords to deliver their electricity. Portable, battery-powered impact wrenches can only reach up to 2,000 RPM, although that’s a perfectly respectable speed as well.
But impact drivers’ advantage here disappears when you compare them to air-powered impact wrenches. Those can blow even the best impact drivers away with 8,000 RPM, more than double what the others offer.
Price
But all that extra speed and torque come at a literal price. Impact wrenches are usually significantly more expensive than impact driver, which means you should really consider how valuable their additional power and speed are for your purposes.
Impact drivers start at around $40 each, which makes them one of the most affordable tools you can have in your shop. While those aren’t the best models on the market, the most expensive impact drivers still won’t bring you far past $300, which is still reasonable for a professional-quality tool.
On the other hand, the least expensive impact wrench you can find will cost more than $125. The most expensive impact wrenches on the market are still surprisingly affordable, clocking in just under $500 for a premium, professional-grade model.
When to Use Impact Driver and Impact Wrench
While impact wrenches are generally stronger and better for heavy-duty applications, impact drivers have the unique ability to provide more continuous energy with each revolution of the bit, which makes them well-suited for driving larger screws or bolts.
Both impact wrenches and impact drivers are well-suited for use on your car or in a workshop setting. If you need to tighten bolts in a place where a normal socket won’t fit, or you have a number of bolts that need to be tightened or loosened at the same time, either an impact wrench or driver can be the best choice.
The Bottom Line
The main difference between impact wrenches and impact drivers is how each tool generates rotational energy.
While impact wrenches use a sudden burst of force, impact drivers create a quick vibration.
Both tools are designed to tackle tough fastening jobs in a variety of settings, but they’re best suited for larger projects where you need to apply more continuous force.
