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SDS max vs SDS plus: which shank fits

Updated: 2026-10-23

The parcel will not lock in the drill you already own. SDS max vs SDS plus is a chuck question before it is a blade question. Max is about 18 mm. Plus is about 10 mm. They do not share a fitting, and a longer max chisel is not a Plus chisel with more reach. This page separates the three names, from UK seller guides and the listings in our [SDS max chisel comparison](/hub/drilling-and-accessories/sds-max-chisel). We did not measure a chuck in a lab. A qualifying purchase through our links can earn a commission at no extra cost to you.

The parcel will not lock in the drill you already own. SDS max vs SDS plus is a chuck question before it is a blade question. Max is about 18 mm. Plus is about 10 mm.

Our top picks

Nucraft Nucraft angled tile chisel

Best overall

Nucraft Nucraft angled tile chisel
9.4/10about £11.04
View offer
Bosch Bosch PRO SDS max-4C flat

Best value

Bosch Bosch PRO SDS max-4C flat
8.2/10about £9.95
View offer
Keewaki Keewaki 4-piece 450 mm

Alternative

Keewaki Keewaki 4-piece 450 mm
7.4/10about £36.99
View offer
On this page
  1. 1.Three names, two sizes
  2. 2.What fails if you mix them
  3. 3.When the heavier shank is the right purchase
  4. 4.In the chuck but not striking

Three names, two sizes

Ordinary SDS and SDS Plus are the same 10 mm family. SDS max is the other system: about 18 mm, with a different groove layout, for heavier rotary hammers and breakers. Heller’s shank guide adds a rough line, under about 5 kg toward Plus and over about 5 kg toward max. Treat the kilograms as manufacturer guidance. The marking on the chuck is the fact. A 2 kg combi drill does not become a max tool because you might hire a breaker next year. A Plus shank is a slim 10 mm rod. A max shank is visibly thicker, about 18 mm. Five pits on a title is that groove pattern, not a Hilti-only chuck. The Shanrya set says SDS max (five pits) and names Hilti. It does not say other max chucks will refuse it. If you still need a tip, the shapes are on the buying guide.

What fails if you mix them

Keewaki’s four-piece listing states an 18 mm SDS max shank and says it is not compatible with 10 mm SDS Plus or hex tools. Reviews on that file, marked United States, still include people who bought max for a Plus drill and sent it back. Nucraft review text says the angled chisel does not work with SDS Plus. A UK buyer returned the Bosch flat because it did not fit an SDS drill. The chisel can be exactly as described and still be useless in the tool you have. An adaptor is not a workaround we can support. The striker, the diameter and the grooves are different. Under the Consumer Rights Act 2015, goods have to be as described. A Plus shank sold as max fails that. A max chisel that will not enter a Plus drill is not faulty. The word SDS in a title is the trap, not the clue.
Nucraft Nucraft angled tile chisel

Testsieger

Nucraft Nucraft angled tile chisel
9.4/10about £11.04
View offer

When the heavier shank is the right purchase

Buy SDS max when the hammer you will use already says SDS max: a hired breaker, a renovation hammer in the 18 mm class, or the tool you own for demolition rather than 10 mm holes in brick. The chisel then matches the job. Max is the wrong purchase when the only drill in the house is Plus and a Plus chisel can already shift the tiles. An 18 mm bit for later is steel you cannot fit. If your chuck is Plus, this comparison is the wrong aisle. If it is max, the seven listings run from £9.95 to £36.99. A Plus drill that stalls on a hard bed needs a better Plus blade or a max hammer, not a max chisel in the small chuck.

In the chuck but not striking

A correct SDS max shank locks and then still slides several centimetres. That float is the blow. A rigid bit is not seated. A review on the Bosch flat describes a chisel that sat in the tool but did not travel, which is a short shank or a shank that never reaches the striker. That is different from a max chisel that will not enter a Plus chuck at all. Clean the grooves, pull the collar back, and seat the shank until the float is there. Grease belongs on the shank, lightly, not on the cutting edge. Rotation has to be off. A chisel left in rotary mode can sit in a max chuck and still do no useful work. If the steel is the slim 10 mm pattern, seating will not make it an 18 mm chisel.

Common questions

Is SDS the same fitting as SDS Plus?
For the 10 mm rotary hammers people mean by a normal SDS drill, yes. Ordinary SDS and SDS Plus share that shank. SDS max is not part of that pair. If the chuck is not marked max, do not buy an 18 mm chisel.
Is SDS max just a longer SDS Plus chisel?
No. Max is about 18 mm against about 10 mm, with a different groove pattern. A 400 mm Plus chisel is still Plus. Length is reach after the chuck matches.
My drill is 2 kg. Should I buy max for a future breaker?
No. A 2 kg drill will not take an 18 mm chisel now. Heller’s weight line is only guidance. Buy Plus steel for the drill you have, and max steel on the day you hire or own an SDS max hammer.
Can an adaptor run an SDS max chisel in a Plus chuck?
Do not rely on one. The diameters, the grooves and the striker are different systems. If Plus will not do the job, the next tool is an SDS max hammer with an SDS max chisel, or a better Plus blade. Forcing the shank is how chucks get damaged.
What does five pits mean on the Shanrya title?
On that listing it is the seller’s name for the max groove pattern, not a Hilti-only chuck. Five pits does not mean Plus, and it does not give you a length. That set does not state millimetres.
The chisel goes in but does not hit. Is that Plus against max?
Only if the shank never really belonged in that chuck. If an 18 mm shank locks and then does nothing, check axial float, a short shank, and hammer-only mode. A Bosch-listing review describes a chisel that sat in the tool but did not travel.

Related pages

Best SDS max chisel

How to use an SDS max chisel

SDS max chisel

Buying an SDS max chisel set: shank, tip and length

SDS max tile chisel: angled blade or straight edge

Sources

Public UK sources from the research digest, last checked on 22 October 2026. Shelf prices and star lines are the amazon.co.uk figures in the display file.

  1. Heller Tools, SDS shank guide (retrieved 22 October 2026)
  2. TEH Tools UK, SDS Plus vs SDS max (retrieved 22 October 2026)
  3. HSE, INDG175 hand-arm vibration (retrieved 22 October 2026)
  4. HSE, vibration controls (retrieved 22 October 2026)
  5. HSE, construction dust CIS36 (retrieved 22 October 2026)
  6. HSE, PUWER overview (retrieved 22 October 2026)
  7. Consumer Rights Act 2015 (retrieved 22 October 2026)
  8. Bosch Professional GB, flat chisels (retrieved 22 October 2026)