# SDS drill vs combi drill for brick, block and concrete

Source: https://drillandbit.co.uk/blog/sds-drill-vs-combi-drill
Published: 2026-10-12
Publisher: Drill and Bit

**In short:** A combi drill is fine for plug holes up to about 8 mm in brick and block. An SDS drill uses a piston to deliver far harder blows, measured in joules, so it drills concrete, larger anchor holes and lots of holes quickly, and most can chisel. If you drill concrete often or need holes above about 10 mm, choose SDS.

Both tools have a hammer action, so why does an SDS drill zip through a concrete lintel while a combi drill squeals and stalls? The answer is the way the hammer works and the bit holder that goes with it. This article compares the two mechanisms, gives typical hole sizes and explains when an SDS drill earns its place alongside a combi.

## Ratchet hammer against piston hammer

A combi drill's hammer comes from two ridged discs riding over each other. The blows are small and fast, and much of the force depends on you pushing the drill into the wall. It works well in soft and medium brick and block but runs out of steam in hard concrete.

An SDS drill, often called a rotary hammer, uses a motor driven piston to fling a striker against the back of the bit. The blows are far stronger and the drill does the work, so you only need light pressure. Makers quote this as impact energy in joules: cordless SDS plus drills commonly range from about 1 to 3 J, as the listings below show.

## The SDS chuck and bits

SDS plus bits have a 10 mm shank with grooves that lock into the chuck while letting the bit slide back and forth. That free movement lets the piston blows reach the tip instead of being absorbed by chuck jaws. Bits push in and click, with no tightening.

The trade off is that SDS bits only fit SDS tools, and round shank wood and metal bits need an adaptor chuck unless the drill has a quick change chuck such as Bosch's OneChuck. Larger SDS max tools use an 18 mm shank for heavy demolition and coring. See [what an SDS drill is](https://drillandbit.co.uk/blog/what-is-an-sds-drill).

## Two DeWalt 18 V drills compared

The table uses listing figures for a DeWalt 18 V XR hammer drill driver and an 18 V XR SDS plus hammer drill.

|  | DeWalt DCD800NT hammer drill driver | DeWalt DCH263N SDS plus |
| --- | --- | --- |
| Hammer type | Ratchet (combi) | Piston, 3.0 J |
| Masonry capacity | Not stated | 4 to 28 mm |
| Chisel mode | No | Rotation stop for light chiselling |
| Clutch for screws | 15 positions | No |
| Supplied as | Bare unit | Bare unit with side handle |

Listing figures, DeWalt 18 V XR

[Compare cordless SDS drills](https://drillandbit.co.uk/best/best-cordless-sds-drills)

## Typical hole sizes and materials

As a rough guide, a good 18 V combi drill handles 5 to 8 mm plug holes in brick and block comfortably and will go to 10 to 13 mm with patience. In dense concrete even small holes are slow. A cordless SDS plus drill handles 5 to 16 mm holes in concrete easily, with heavier models reaching 26 to 28 mm. Always check the capacity in the listing and the bit maker's guidance.

| Job | Combi drill | SDS plus drill |
| --- | --- | --- |
| Shelf plugs in brick, 6 mm | Good | Good |
| TV bracket in block, 8 to 10 mm | Fine | Fast |
| Frame fixings in concrete, 10 mm | Slow | Good |
| Resin anchors, 12 to 16 mm | Struggles | Good |
| Lifting tiles, chasing small channels | No | Yes, with chisel mode |
| Wood and metal holes, screws | Yes | Needs adaptor, no clutch |

Typical choices, check your tool's stated capacity

## Do you need both?

For occasional shelves and brackets, a combi drill is enough. If you are renovating, fitting a kitchen to block walls, putting up fencing on concrete or doing lots of fixings, an SDS drill saves time and wrists, and a combi drill or impact driver handles the screws.

Many people add a bare SDS drill on the battery platform they already own. Our [combi drill kit guide](https://drillandbit.co.uk/best/best-combi-drill-kits) and [SDS guide](https://drillandbit.co.uk/best/best-cordless-sds-drills) show which come with batteries.

Note: SDS drills can twist hard if a bit jams on rebar. Use the side handle, rely on kickback control where fitted, scan for cables and pipes first, and wear eye, ear and dust protection. Silica dust from concrete and brick is harmful, so use extraction or a suitable mask as HSE advises.

## Frequently asked questions

**Can I use SDS bits in a combi drill?** No. SDS bits need an SDS chuck. Some combi drills accept hex or round bits only.

**Can an SDS drill drive screws?** Not well. Most have no clutch and run too fast. Use a combi drill or impact driver for screws.

**What does SDS stand for?** It comes from the German Steck, Dreh, Sitz, roughly insert, twist, stays, describing how the bit locks in. SDS plus is the common size for cordless tools.

**Is a 12 V SDS drill worth it?** For small fixing holes overhead, yes. For anchors above about 10 mm or lots of concrete, an 18 V model with more joules is better.

## Buying guides on this topic

- https://drillandbit.co.uk/best/best-cordless-sds-drills
- https://drillandbit.co.uk/best/best-combi-drill-kits
- https://drillandbit.co.uk/best/dewalt-18v-xr-drills-compared

## Sources

- [HSE: construction health and safety](https://www.hse.gov.uk/construction/)
- [DeWalt UK](https://www.dewalt.co.uk/)