Impact Driver vs. Impact Wrench: What's the Difference?
The names get used almost interchangeably, and both tools share that unmistakable rapid-fire hammering sound, so it's an easy mix-up to make. But an impact driver and an impact wrench are built around different drive systems and different fasteners, and grabbing the wrong one for the job usually means stripped bits or a tool that can't get the torque done.
Here's what actually separates them, and which one most home DIYers should buy first.
The drive system is the real difference
An impact driver uses a 1/4-inch hex quick-change chuck, the same style of bit holder as a standard drill. That makes it built for screwdriver and drill bits — Phillips, Torx, square-drive screws, and small hex-shank drill bits.
An impact wrench uses a square drive, almost always 1/2-inch on consumer models, held in place by a spring-loaded detent pin or a friction ring. That's the same style of drive used on torque wrenches and breaker bars, built to hold sockets rather than screwdriver bits.
Torque numbers aren't apples-to-apples
Impact drivers for home use typically deliver somewhere in the 1,500-3,000 inch-pound range, which converts to roughly 125-250 foot-pounds — plenty for deck screws, lag bolts, and general construction fasteners.
Impact wrenches are built for a different scale entirely. Even a compact cordless impact wrench commonly delivers 300-700+ foot-pounds, and heavier-duty models built for truck lug nuts or equipment work can go well beyond that. That gap is why you can't substitute one tool for the other on demanding fasteners.
What each tool is actually built for
Impact drivers earn their keep on woodworking and general construction: deck screws, subfloor screws, lag bolts, framing, and any job where you're driving fasteners with a screwdriver-style bit rather than a socket.
Impact wrenches are the go-to for automotive and heavy hardware work — lug nuts, suspension bolts, and equipment fasteners that need a socket and real torque to break loose or seat properly. Tire shops and mechanics rely on them for exactly this reason.
Which one do you actually need first
If you're building a general home DIY kit — furniture, decking, framing, household repairs — an impact driver is the far more useful first purchase, and it's the one most combo kits pair with a drill.
Only add an impact wrench once you have a specific need for it, like regularly rotating tires, doing your own brake work, or working on equipment with large bolted fasteners. For occasional lug nut changes, a manual breaker bar and torque wrench still get the job done without another tool to store and charge.
Frequently Asked Questions
- Can I use an impact driver on lug nuts?
- It's not a good idea as your main method. Most impact drivers don't have the torque to reliably break loose tight lug nuts, and you'd need a hex-to-square adapter since impact drivers don't accept sockets directly. Use a proper impact wrench or a breaker bar and torque wrench instead.
- Can an impact wrench drive screws?
- Technically, with a socket-to-hex adapter, but it's a poor match — impact wrenches are bulkier, heavier, and deliver far more torque than screws need, making it easy to strip or overdrive them. Stick with an impact driver or drill for screws.
- Do impact drivers and impact wrenches share batteries?
- If you buy them from the same brand's cordless platform, yes — a Milwaukee M18 impact wrench runs on the same batteries as an M18 impact driver, for example. That's worth factoring in if you're planning to add both tools over time.