Impact Driver vs Impact Wrench
Same hammer-and-anvil principle, different output end and very different torque. Here is how to tell which one you need.
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An impact driver has a 1/4-inch hex collet for screwdriver bits and is built for screws and small bolts. An impact wrench has a square drive (usually 3/8 or 1/2-inch) for sockets and is built for nuts and bolts. A 1/2-inch impact wrench delivers several times the torque of an impact driver, which is why it handles lug nuts and suspension bolts. For wood screws, decking and cabinets, choose the impact driver. For cars, equipment and heavy steel fasteners, choose the impact wrench.
On this page
The short version
Both tools use a hammer-and-anvil mechanism that adds rotational blows. The differences are in the output end, the amount of torque and the fasteners each one is meant for.
| Feature | Impact driver | Impact wrench |
|---|---|---|
| Output | 1/4-inch hex quick-release collet | Square drive anvil: 1/4, 3/8, 1/2, 3/4 or 1-inch |
| Takes | Hex bits, hex-shank sockets, adapters | Impact sockets |
| Typical torque | 1,500 to 2,200 in-lbs (125 to 185 ft-lbs) | 1/2-inch mid-torque: hundreds of ft-lbs; high-torque: over 1,000 ft-lbs |
| Best for | Screws, lags, small bolts | Nuts, bolts, lug nuts, heavy steel |
| Control | Fine, with low speed modes | Coarser; built for power |
| Size and weight | Compact and light | Compact (3/8) to large (1/2 high-torque) |
Note the units: impact drivers are usually rated in inch-pounds and impact wrenches in foot-pounds. Divide in-lbs by 12 to compare. A 2,000 in-lb impact driver is about 167 ft-lbs.
What each tool is really for
Impact driver
- Wood screws, deck and framing screws, structural screws
- Lag bolts up to moderate sizes (with a socket adapter)
- Self-drilling screws into metal
- Small nuts and bolts on brackets, appliances and equipment panels
Impact wrench
- Lug nuts and wheel work
- Suspension, brake caliper brackets and subframe bolts
- Large lag bolts and carriage bolts in timber construction
- Machinery, trailers and agricultural equipment
- Seized and rusted fasteners
Choosing an impact wrench size
| Drive | Typical use |
|---|---|
| 1/4-inch | Small fasteners, interior and engine-bay trim. Overlaps with impact drivers. |
| 3/8-inch | Engine bay, brackets, motorcycle work; compact and easy to reach with |
| 1/2-inch mid-torque | Lug nuts and most automotive and construction bolts |
| 1/2-inch high-torque | Seized, large and heavy-equipment fasteners |
| 3/4 and 1-inch | Heavy truck, mining and industrial work |
Using sockets on an impact driver
An impact driver with a hex-to-square adapter handles small nuts and bolts well. Three rules:
- Use impact-rated adapters and sockets. Black impact sockets are made from tougher steel. Chrome hand-tool sockets can crack.
- Expect adapters to be the weak link. On large or seized fasteners, the small square tip snaps before the bolt moves. That is your sign to switch to an impact wrench.
- Keep extensions short. Long extensions absorb blows and add wobble.
Impact socket adapters on Amazon Socket picks
Can an impact driver remove lug nuts?
Sometimes. Passenger car lug nuts are typically tightened to roughly 80 to 100 ft-lbs, and many trucks and SUVs to more. A flagship impact driver's rated output is in that range, but rust, overtightening and adapter flex make removal unreliable, and you risk snapping the adapter. Use an impact wrench for wheel work. Never use any impact tool to final-tighten lug nuts. Finish with a torque wrench to the vehicle's specification. More in can an impact driver remove lug nuts?
Which should you buy?
- Woodworking, decks, home projects: impact driver.
- Car and tire work: a 1/2-inch mid-torque impact wrench, plus an impact driver for interior and small fasteners. See using an impact driver for car work.
- Timber framing and large lags: an impact driver for most fasteners, and an impact wrench for the biggest bolts.
- One tool only, mostly screws: impact driver with a set of adapters.
Stay on your existing battery platform. Every major brand sells both tools as bare units. If you are starting fresh, read choosing a cordless tool platform.
Verdict
Screws and wood: impact driver. Nuts, bolts and steel: impact wrench. An impact driver with adapters stretches into light bolt work, but once adapters start snapping or fasteners will not budge, you have reached impact wrench territory.
Frequently asked questions
Can I use sockets on an impact driver?
Yes, with a hex-to-square adapter or hex-shank sockets. This works well for small nuts and bolts. Use impact-rated (black) sockets and adapters, because chrome sockets can crack under impact.
Can an impact wrench drive screws?
With a square-to-hex bit adapter it can, but it is heavy, often too powerful and lacks the fine control needed for wood screws. It is not a practical substitute.
Is 2,000 in-lbs enough to remove lug nuts?
2,000 in-lbs is about 167 ft-lbs, above the tightening spec for many passenger cars. Rusted or overtightened lugs often need far more to break loose, and adapters can snap. It may work on some cars, but an impact wrench is the right tool. Always final-tighten lug nuts with a torque wrench.
What size impact wrench should I get for car work?
A 1/2-inch mid-torque impact wrench handles lug nuts and most suspension work. A 3/8-inch compact wrench is better for engine-bay bolts. High-torque 1/2-inch models are for seized and large fasteners.
What is a hex impact wrench?
Some compact wrenches and impact drivers blur the line. Several brands sell 3/8-inch and 1/4-inch square-drive compact impact wrenches that are close to impact-driver size. Check the drive type, not just the size.