SDS Drills: What They Are, Which to Buy, and How to Use One Properly

You're three weeks into an extension build. The electrician needs cable routes chased into the blockwork. The plumber needs a 25mm hole through the kitchen wall for a waste pipe. Your builder's drilling anchor bolt holes into concrete for the new steel beam. Every one of those jobs needs an SDS drill, and every one of them will go badly with a standard combi drill. If you've spent ten minutes grinding a 10mm hole into a brick wall with a cordless drill, watching the bit spin uselessly while your hand aches, you already know the problem.

What it is and when you need one

SDS stands for Steck, Dreh, Sitz (German for insert, twist, sit) and describes the chuck system, the part that holds the drill bit. Unlike a standard chuck that tightens jaws around a smooth shank, an SDS chuck has spring-loaded ball bearings that lock into slots on the bit. Push it in, it clicks. Pull the collar, it releases. No tightening, no slipping.

The real difference is the hammer mechanism. An SDS drill hammers the bit forward at up to 4,000 beats per minute while spinning, pulverising the masonry rather than grinding through it. A combi drill has a rudimentary hammer action too, but it's weak, typically under 1 joule of impact energy. An SDS drill delivers 2 to 5 joules. That's the difference between five minutes of struggling on a single 8mm hole in brick, and punching through in ten seconds.

You need an SDS drill for:

• Fixing holes into brick, concrete block, or poured concrete
• Larger holes (12mm to 25mm) for pipe and cable routes through masonry
• Chasing cable channels into blockwork using a chisel attachment
• Removing tiles (chisel mode)
• Light demolition, knocking out small areas of blockwork or render

You don't need one for timber, metal, or plasterboard. A combi drill handles those. And for heavy demolition (knocking down a wall, breaking up a concrete slab), you need an SDS-Max breaker or a kango, not an SDS+ drill.

SDS+ vs SDS-Max

Two chuck systems exist, and their bits are not interchangeable.

SDS+ (also called SDS-Plus) uses a 10mm diameter shank with two open grooves and two closed grooves. It's the standard for domestic and light trade work. Every drill discussed on this page is SDS+. Bit sizes range from 5mm to 25mm diameter, and you can drill holes up to about 300mm deep. Impact energy on SDS+ drills runs from 1.5 to about 5 joules. For an extension project, SDS+ handles everything.

SDS-Max uses an 18mm shank and is found on heavy-duty breakers and large rotary hammers. These are demolition and civil engineering tools generating 8 to 20 joules. They drill holes from 12mm to 80mm diameter and over a metre deep. You'll never need one as a homeowner. If a task calls for SDS-Max, it's a job for a contractor with their own kit.

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The three modes and when to use each

Most SDS drills worth buying have three operating modes, selected by a rotary switch on the body. Using the wrong mode is one of the most common beginner mistakes, and it explains why some people think their SDS drill "doesn't work properly."

Mode 1: Rotation only. The bit spins but doesn't hammer. Use this for drilling into wood or metal with an SDS-shanked bit, or for mixing plaster and compound with a paddle attachment. Never use this mode on masonry. The bit will spin on the surface and go nowhere.

Mode 2: Hammer plus rotation. The bit spins and hammers simultaneously. This is the default for all masonry drilling. Fixing holes in brick, anchor bolts in concrete, pipe routes through walls. You'll use this mode 90% of the time.

Mode 3: Hammer only (chisel mode). The bit hammers but doesn't rotate. Use this with a flat chisel for chasing cable routes into blockwork, removing tiles, or chipping away render. The bit stays oriented in the direction you point it. Two-function drills (modes 1 and 2 only) skip this mode, and that's a false economy. Cable chasing alone makes the chisel function worth paying for.

Understanding joule ratings

Every SDS drill has a joule rating on the spec sheet. It's the single most important number for comparing drills. Wattage tells you how much electricity the motor draws. RPM tells you how fast the bit spins. Joules tell you how hard the hammer hits, and that determines whether a drill breezes through dense concrete or labours.

Here's what different ratings mean in practice:

• 1.0-1.5J (compact cordless models): Fine for occasional 6-8mm fixing holes in ordinary brick. Will struggle with dense block and concrete. Not enough for extension work.
• 2.0-3.0J (standard SDS+ range): The sweet spot. Handles every masonry drilling task on a domestic extension. Most mid-range corded drills sit here.
• 3.5-5.0J (heavy-duty SDS+): More power than most homeowners need. Useful if you're drilling many large holes (20mm+) into reinforced concrete, but heavier and more expensive.

Don't chase the highest joule number. A 5J drill weighs more, kicks harder, and costs twice as much as a 2.6J drill that does everything you need.

Corded vs cordless

This is the question that fills forum threads. The answer depends on how you'll use the drill and whether you're already invested in a battery platform.

Corded SDS drills plug into a 230V socket and deliver full power continuously. They're lighter (no battery), they never run flat, and they cost far less. A quality corded SDS+ starts at around £65. The trade-off: you need a socket and you're tethered to a cable. For extension work where the house is right there, this is rarely a problem.

Cordless SDS drills run on 18V lithium-ion batteries (some pro models use 54V twin-battery systems). Modern brushless 18V models have closed the performance gap for intermittent use, and cable-free drilling is genuinely useful on upper floors or outside. But you'll pay £150 – £300 for drill plus batteries, and cold weather reduces battery life noticeably.

The practical answer for homeowners: If you don't already own 18V batteries from another brand, buy a corded SDS drill. You'll get equal or better drilling performance for half the price. If you already have DeWalt, Makita, or Milwaukee batteries from other tools, a cordless body-only SDS makes sense as an addition to your kit.

How to use it properly

An SDS drill is more powerful than a combi drill, which means technique matters more, not less.

Before you start

Mark your hole position with a pencil cross. On hard surfaces, use a centre punch to create a small indent. This stops the bit walking (sliding sideways) when you start drilling.

Set the depth stop, the rod that slides through a clamp on the side handle. Adjust it so the bit protrudes exactly as deep as you need. For a 50mm anchor bolt hole, set the stop at 55mm (extra clearance for dust at the bottom).

Fit the side handle. Always. SDS drills generate serious torque and kick-back. Without the side handle, the drill can wrench out of your grip. This isn't a suggestion.

Drilling technique

Start slowly. Apply firm, steady pressure and let the hammer action do the cutting. Don't lean your full weight into the drill. Excessive pressure overloads the hammer mechanism and actually slows progress.

Pull the bit out periodically (every 20-30mm of depth) to clear dust from the hole. The flutes on the bit carry dust out, but in deep holes they pack up. A clogged hole means the bit is grinding the same dust instead of cutting fresh material.

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Using chisel mode

Switch to mode 3 (hammer only). Fit a flat chisel bit for chasing channels or a pointed chisel for spot removal. Hold the drill at a shallow angle to the surface, around 30 to 45 degrees. Let the hammer do the work. Pushing too hard buries the chisel and stalls the mechanism.

For cable chasing in blockwork, make two parallel cuts with a masonry bit first (one each side of the chase), then switch to the flat chisel to knock out the material between them. This gives a much neater chase than trying to chisel a channel freehand.

What to buy

Three tiers. Real models, real prices, based on what's currently available at major UK retailers.

Budget: £50 – £100 (corded)

The ROKTOR 1000W SDS+ at Toolstation (£65) is a competent entry point with plenty of power. The Einhell 800W three-function SDS+ at around £100is a better-built machine with a proper three-function selector.

Budget drills use brushed motors. They work fine for intermittent use, but carbon brushes (small spring-loaded blocks that transfer electricity to the motor) wear down over time. On some budget models, the brushes aren't replaceable, making the drill disposable. Check before you buy. The Erbauer SDS+ at Screwfix (around £803J, replaceable brushes) is worth the step up from a £49Titan for this reason alone.

A budget corded SDS drill will last years of occasional use. Forum users report 15 to 20 years from corded Bosch and Makita models.

Mid-range: £110 – £160 (corded)

This is where the trusted trade names live, and where most homeowners should buy.

Bosch GBH 2-26 (£120at Screwfix). 830W, 2.7J, 2.7kg, three-function with anti-vibration. The Bosch workhorse that appears on building sites across the UK. Carry case, 4m cable, one-year guarantee.

DeWalt D25133K (£125 – £150 depending on retailer). 800W, 2.6J, 2.6kg, three-function with lock-on switch. Three-year guarantee (registration required). Slightly less impact energy than the Bosch but a longer warranty.

Makita HR2670 (£130at Toolstation). 800W, 2.9kg, three-function. Makita's current mid-range corded SDS+, replacing the HR2470 which is now on clearance. If you see an HR2470 discounted, grab it, but stock is running out.

All three are excellent. Pick whichever brand's ergonomics feel right in your hand.

Professional/cordless: £200 – £350

This tier is predominantly cordless kits with one or two 18V batteries. Buy here if you already own branded batteries or if portability matters more than outright value.

DeWalt DCH133P1 (£200at Toolstation). 18V XR brushless, one 5.0Ah battery, three-function. Compact and well-balanced. The brushless motor runs cooler and lasts longer than brushed equivalents.

Milwaukee M18BLHX-501X (£300at Toolstation). 18V brushless, one 5.0Ah battery, SDS+. Milwaukee's mid-pro offering. More power than the DeWalt but heavier and pricier.

Body-only prices (no battery) run £145 – £230 which is the route to take if you already own compatible batteries. A 5.0Ah battery alone costs £60 – £120 depending on brand.

Drill bits and accessories

The drill is half the purchase. You need SDS+ bits to go with it, and buying the right set upfront saves repeated trips to the shop mid-build.

A basic SDS+ masonry bit set covers the most-used fixing sizes (6mm, 7mm, 8mm, and 10mm). Budget sets start at £9(Toolstation Minotaur). Branded sets from DeWalt (£15) or Bosch (£22) use better carbide tips that stay sharp longer. For an extension build, spend the extra on branded bits.

A combined drill bit and chisel set (around ~£30 for 15 pieces) gives you a flat chisel, pointed chisel, and a selection of bit sizes in one box. That's the practical starter purchase alongside the drill. Individual bits for specific jobs (a 25mm bit for waste pipe routes) cost £5 – £18 depending on diameter.

Hire vs buy

SDS drill hire runs roughly £25 – £45 per day from national hire companies (Jewson, HSS, Speedy). A budget corded SDS+ costs £65 – £80. Two to three hire days equals the purchase price of a tool you keep forever. If your build involves masonry drilling across multiple phases (and it will), buying beats hiring within the first week. Hire only makes sense for a genuine one-off job.

Alternatives

If you only need small fixing holes (6-8mm) in ordinary brick, a combi drill with a masonry bit will manage. Slower and messier, but it works for a handful of holes. Don't buy an SDS drill just to hang a shelf.

For holes larger than 25mm through masonry (soil pipe routes, flue holes), you need a core drill with diamond-tipped bits. Different tool, different technique.

For drilling into steel beams (RSJs), an SDS drill is the wrong tool entirely. Large holes in structural steel need a magnetic drill, which is strictly a hire item.

Where you'll need this

SDS drills appear across nearly every phase of an extension or renovation project:

• Foundations and footings - drilling into existing masonry for starter bars that tie the new foundation to the house wall
• Drainage - drilling through existing masonry walls to connect new drainage runs
• Steels and lintels - drilling for resin-anchored bolts and fixing plates that secure steel beams
• Windows and doors - drilling frame fixings into the masonry openings
• Bifold and sliding doors - fixing outer frames and tracks into masonry
• First fix electrics - chasing into blockwork for cable routes in solid-wall construction
• Extractor and ventilation - fixing ducting brackets and vent grilles to masonry walls
• Garden and external works - fixing downpipes, wall lights, and cable clips to the new masonry

Safety

Fit the side handle before every use. SDS drills can kick back violently if the bit catches rebar or hard aggregate. Without the side handle, the drill twists out of your grip.

For drilling fixing holes in masonry indoors, an FFP2 dust mask is adequate. For cable chasing into blockwork — which generates far more concentrated silica dust — you need an FFP3 mask. The grinding action of the chisel releases dust at levels that exceed the safe exposure limit for silica within minutes. A dust extraction shroud connected to a vacuum also helps control dust at source for indoor chasing work, but it doesn't replace the mask.

Unplug corded drills before changing bits. On cordless models, remove the battery. An accidental trigger press with your hand near the chuck is a crush injury waiting to happen.