One drives fasteners with rotational impacts, the other hammers along the axis. What separates an impact driver from an impact drill, and when to use each.

An impact driver and an impact drill look almost the same: similar housing, the same battery, similar noise. Both are called "impact" tools, but they apply force in opposite directions. One drives fasteners with rotational impacts. The other hammers along the bit axis to drill into masonry.

Choosing the wrong tool can slow the job down or damage the bit: an impact driver will not drill into concrete effectively, and a hammer drill is slow and awkward for driving screws.

The Short Answer

• Both tools are called "impact", but the mechanisms are different. An impact driver delivers rotational impacts to the bit holder; an impact drill drives a hammering pulse along the chuck axis.
• You can usually tell them apart by looking at the bit holder: a 1/4-inch hex collet means impact driver, a three-jaw keyless chuck means impact drill.
• They do different jobs and are not interchangeable. If the work involves both masonry holes and long fasteners, plan on owning both.

What Each Tool Does

Impact driver

An impact driver is built for fastening. It takes 1/4-inch hex driver bits in a quick-change collet, and it drives screws, structural screws and lag bolts that would stall an ordinary drill/driver. The turning force comes from the mechanism, not from the user’s wrist. When the bit meets resistance, an internal hammer strikes an anvil and adds a short rotational blow. The tool keeps driving, and the user feels less reaction torque. Torque is quoted as a peak figure: our own cordless impact driver is rated at 150 N·m, with a no-load speed of 0-2,400 rpm and an impact rate of 0-3,000 bpm.

Impact Drill vs Hammer Drill: Naming Differences

Outside North America, "impact drill" nearly always means the tool that North American suppliers call a hammer drill: a rotary drill with a hammer mode. Two ridged cam plates slide against each other and move the chuck back and forth along the bit axis while it turns. The bit chips the masonry instead of cutting it, and rotation clears the dust.

Hammer mode can be switched off, so the tool also works as a standard rotary drill for wood, metal and plastic. Because the hammering is axial, it needs a masonry bit; a standard twist bit will overheat. Our 20V brushless impact drill is a typical example: a 1/2-inch (13 mm) metal keyless chuck, 20+3 clutch settings, 65 N·m maximum torque, and two speed ranges of 0-450 and 0-1,650 rpm.

Where the rotary hammer fits

A third tool is often confused with these two. A rotary hammer uses a pneumatic piston instead of sliding cams, delivers far more energy per blow, and takes SDS bits that slide axially in the chuck. It is the right tool for holes above roughly 12 mm, for poured concrete with aggregate or rebar, and for chiselling. An impact drill handles occasional holes in brick and block. For concrete work you do regularly, a rotary hammer is the right tool.

How the Two "Impact" Mechanisms Differ

The main difference is the direction of the impact force.

• Impact drill - force along the axis. The cams convert motor rotation into a linear pulse, so the bit is struck in the direction it is already drilling. The rate is high, commonly 20,000 to 50,000 blows per minute, but each blow carries little energy.
• Impact driver - force around the axis. A hammer is thrown outward by centrifugal force and strikes an anvil fixed to the output shaft, so the bit holder receives a twisting blow. The rate is far lower, roughly 2,000 to 4,000 impacts per minute, and each one carries far more energy.

This is why blows per minute and impacts per minute cannot be compared directly, even though datasheets list them the same way. A hammer drill at 34,000 bpm and an impact driver at 3,000 are not measuring the same thing.

Engagement timing differs too. A hammer drill hammers whenever hammer mode is selected, whether or not the bit is under load. An impact driver stays in plain rotation until the fastener resists.

Impact Driver vs Impact Drill: Feature Comparison

Reading the Torque Numbers

Torque figures are easy to get wrong. Three things to watch:

• Peak versus sustained. An impact driver’s figure is measured at the moment of impact. It tells you how much torque the tool can apply to break a fastener loose, not what it applies continuously.
• The clutch sets the working torque. A hammer drill’s maximum torque is modest by design. The 20+3 settings on our impact drill let you reduce torque so the fastener, the gearbox and the tool are not overloaded.
• The units are not used consistently. IPM and BPM are often swapped on datasheets. Our impact driver is listed at 0-3,000 bpm, even though the usual unit for this mechanism is impacts per minute.

For tools from the same brand and voltage class, a higher impact driver rating means more capacity on long or large-diameter fasteners. It tells you nothing about drilling harder materials. For how torque ratings are derived, see Understanding Drill Torque.

Best Uses for Each Tool

Can One Replace the Other?

Partly, and it depends on the job.

An impact driver can drill holes with 1/4-inch hex-shank bits. In wood and light-gauge metal it works, though the impact action can walk the bit off a marked centre point, and the collet allows more runout than a three-jaw chuck, so it is harder to place a hole accurately. In masonry it will not work, and the bit will overheat.

A hammer drill can drive screws, and the clutch helps control torque at low settings. It is still slower on long fasteners, the percussion contributes nothing to a screw, and the extra weight is noticeable when driving hundreds of screws. Neither tool is ideal for the other’s main task: concrete needs percussion along the axis, and long runs of screws need torque around it. For how the collet and the three-jaw chuck differ in grip and bit compatibility, see Types of Drill Chucks Explained.

What to Check Before Buying

• Battery platform first. Committing to one 18 V or 20 V system is worth more than a marginal gain on a single tool. Where part of the work is bench-based, Corded vs Cordless Drills covers where a corded tool still wins.
• Collet or chuck. Confirm the collet size - 1/4-inch hex is standard - and the drill’s chuck capacity, ideally 1-2 mm above the largest bit shank you plan to use.
• Torque and clutch settings. For the impact driver, look at peak torque and trigger speed control; for the drill, count clutch settings as well as maximum torque.
• Impact rate and body length. BPM governs how fast masonry is chipped, and impact energy in joules is the more meaningful figure where it is published. A shorter impact driver head fits into spaces a longer tool cannot.

Frequently Asked Questions

Is an impact drill the same as a hammer drill?

Yes. "Impact drill" is the usual term in the UK, Europe and Australia for the tool sold in North America as a hammer drill: a rotary drill with a selectable hammer mode driven by sliding cams. It is not the same tool as an impact driver.

Can an impact driver drill holes?

Only with hex-shank drill bits, and only in wood or light-gauge metal. It has no hammering action, so it cannot drill into masonry. An impact drill in rotary mode is the better choice when the hole needs to be accurate.

Which has more torque, an impact driver or an impact drill?

The impact driver, by a wide margin, because its hammer-and-anvil mechanism multiplies motor torque in short bursts. A hammer drill’s torque is deliberately lower and limited by its clutch; its advantage is percussion, not turning force.

Do I need both tools?

If the work includes masonry holes and repetitive fastening, yes. If the job is regular driving on site, a cordless impact driver is the tool that gets used every day.

Which Tool Should You Choose?

Because the names sound similar, the two tools are often confused. The answer is to start from the job: a hole in brick, or a fastener driven into dense material. The bit holder tells you which tool you are holding - a three-jaw chuck and a hammer mode for masonry, a hex collet and rotational impact for fasteners.

Looking for impact drills or impact drivers for a particular market? Tell us the material, the fastener or hole size and the destination. We supply both formats, cordless and corded, with the documentation each market requires - see our cordless impact drills and electric impact drills, check the compliance side in Power Tool Certifications, or contact us for a quote.

This article is intended as a general buying reference. Specifications quoted are typical for the class; confirm ratings on the current datasheet before specifying.