Combi Drill vs Impact Driver: Do You Need Both?

The Most Common Tool Question

Walk into any trade supplier and you'll see combi drills and impact drivers sold separately and as twin packs. What's the difference? Do you actually need both? Let's sort this out.

What Each Tool Does

Combi drill:

A versatile drill that combines:

• Drilling mode for putting holes in things
• Hammer mode for drilling into masonry
• Screwdriver mode with clutch for driving screws

Impact driver:

A dedicated screwdriving tool that uses:

• Rotational impacts to drive screws
• High torque with less wrist strain
• Compact size for tight spaces

The Key Differences

Torque delivery:

• Combi drill: Constant torque from motor
• Impact driver: Pulsing impacts that multiply torque

The impact driver delivers much higher torque (often 150-200Nm vs 60-80Nm for combi drills) but in rapid bursts.

Size and weight:

• Impact drivers are typically shorter and lighter
• Better for overhead work and tight spots
• Less fatigue over a day of driving screws

Chuck type:

• Combi drill: Keyless chuck takes round and hex shank bits
• Impact driver: Hex collet takes only 1/4" hex bits

What Each Tool Does Best

Use the combi drill for:

• Drilling holes in wood, metal, plastic
• Drilling into masonry (hammer mode)
• Delicate screwdriving where clutch control matters
• Using round-shank bits

Use the impact driver for:

• Driving screws all day - it's what it's designed for
• Long screws that would stall a drill
• Coach bolts and large fixings
• Tight spaces where length matters
• Overhead work where weight matters

Why Most Tradesmen Have Both

The workflow goes like this:

1. Pick up combi drill with drill bit - make pilot hole
2. Pick up impact driver with screwdriver bit - drive screw
3. Repeat

No changing bits constantly. Much faster workflow. Less wear on both tools.

DeWalt and Makita both sell twin packs for exactly this reason - they know professionals use both together.

Can One Tool Do Both Jobs?

Combi drill only:

• Yes, it can drive screws
• But slower, more wrist strain, less torque
• Clutch settings help but limit power
• Acceptable for occasional use, frustrating for daily

Impact driver only:

• Can drill holes with hex-shank bits
• But no hammer function for masonry
• Less precision for small holes
• No clutch for delicate work
• Limited to hex-shank bits

Neither does the other's job as well as the specialist tool.

If You Can Only Buy One

Buy the combi drill if:

• You drill into masonry regularly
• You need versatility over specialisation
• You drive screws occasionally, not constantly
• Budget limits you to one tool

Buy the impact driver if:

• You already have a drill for holes
• You drive lots of screws
• Deck building, stud walls, general construction
• You work in tight spaces

The Smart Buying Strategy

If you're building a kit:

1. Start with a combi drill - it's more versatile
2. Add an impact driver when screwdriving volume justifies it
3. Consider a twin pack if buying both together - usually cheaper
4. Get both on the same battery platform

What About Impact Wrenches?

Impact wrenches are different again - they're for nuts and bolts, not screws. Square drive socket fitting. Useful for mechanics and some construction, but not a substitute for either drill or driver.

The Verdict

Professional tradesmen: yes, you need both. The workflow improvement alone justifies the cost. A quality twin pack is one of the best tool investments you'll make.

DIYers and occasional users: a good combi drill handles most tasks. Add an impact driver when you find yourself driving lots of screws.