Impact Wrench vs Impact Driver, Explained
An impact driver takes 1/4 inch hex bits and drives screws, while an impact wrench takes square drive sockets and turns big nuts and bolts with more torque.
By Andrian ChengContributing writer.
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The short answer
Both tools look alike and both hammer while they turn, but they are built for different fasteners:
- Impact driver: a 1/4 inch hex collet for hex shank bits. Made for screws: decking, cabinets, furniture and light framing.
- Impact wrench: a square drive for sockets. Made for nuts and bolts: lug nuts, large lag bolts and rusted or seized hardware.
Kreg, which explains both tools in a 2026 guide, sums it up by job: pick the driver if you mostly drive screws and the wrench if you work on vehicles or big bolts.
Side by side
| Impact driver | Impact wrench | |
|---|---|---|
| Tool end | 1/4 inch hex collet | Square drive anvil, usually 1/4, 3/8 or 1/2 inch |
| Takes | Hex shank bits | Sockets |
| Torque | Measured in inch-pounds | Measured in foot-pounds |
| Speed | Higher | Lower, with harder blows |
| Size | Compact and light | Larger and heavier |
Square drive sizes come from Homebuilding and Renovating, which also notes that larger square drives exist for industrial work.
How big is the torque gap?
Torque is the turning force on the fastener. Impact drivers are usually rated in inch-pounds and wrenches in foot-pounds, so the numbers are not directly comparable until you convert them (12 inch-pounds make one foot-pound). Two of Milwaukee's M18 FUEL tools show the gap:
| Milwaukee tool | Rated torque |
|---|---|
| 2953-20 impact driver (1/4 inch hex) | 2,000 inch-pounds (about 167 foot-pounds) |
| 2967-20 high torque impact wrench (1/2 inch) | 1,200 foot-pounds fastening, 1,600 foot-pounds nut-busting |
Nut-busting torque is the figure for breaking a stuck nut loose; fastening torque is for tightening. These are two specific models, so compare the ratings of the exact tools you are looking at.
Can one do the other's job?
Up to a point. A Ryobi trainer quoted by Homebuilding and Renovating says an impact driver can turn nuts and bolts up to about 3/8 inch. Adapters exist that let a driver turn a socket or a wrench turn a hex bit, but the same article advises using each tool as its maker intended. For the driver, the trainer recommends impact-rated bits, which are made to take the extra force.
Too much torque is a risk of its own. Milwaukee's 2967-20, for example, has a shutoff mode that the maker says prevents over-tightening by limiting torque to 50 foot-pounds.
Cordless or air
Cordless impact wrenches need no compressor and go anywhere. Air (pneumatic) wrenches are powerful but must be hooked to a compressor, Kreg notes.
On Wiki Shopping, 30 impact wrenches list a 1/2 inch drive and 7 a 3/8 inch drive. Batteries listed include 18V (7 wrenches), 20V (7) and 21V (8).
How we count
Drive size and voltage are read from each impact wrench's store listing on October 27, 2026, out of 65 impact wrenches listed. Wrenches that do not state them are left out of those counts. The counts change as listings are added or removed.