How to use an SDS max chisel
Updated: 2026-10-23
The first blow is where the job starts cleanly or the shank snaps. How to use an SDS max chisel comes down to a light coat of grease on the shank, hammer-only mode, and a line of blow you do not lever out of. Dust and time on the trigger are part of the job. We did not time a breaker or measure vibration on these bits. The [SDS max chisel comparison](/hub/drilling-and-accessories/sds-max-chisel) is the product table if you still need a tip. A qualifying purchase through our links can earn a commission at no extra cost to you.
The first blow is where the job starts cleanly or the shank snaps. How to use an SDS max chisel comes down to a light coat of grease on the shank, hammer-only mode, and a line of blow you do not lever out of.
The first blow is where the job starts cleanly or the shank snaps. How to use an SDS max chisel comes down to a light coat of grease on the shank, hammer-only mode, and a line of blow you do not lever out of. Dust and time on the trigger are part of the job. We did not time a breaker or measure vibration on these bits. The SDS max chisel comparison is the product table if you still need a tip. A qualifying purchase through our links can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Shank | Tip | Length | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Nucraft Nucraft angled tile chisel | SDS max | Wide tile chisel | 300 mm in the title | 9.4 | about £11.04 | View offer |
| Best value |  Bosch Bosch PRO SDS max-4C flat | SDS max | Flat only | 280 mm and 37 cm | 8.2 | about £9.95 | View offer |
| Alternative |  Keewaki Keewaki 4-piece 450 mm | SDS max, 18 mm, 5-slot | Point, flat, wide, U-groove | 450 mm | 7.4 | about £36.99 | View offer |
On this page
Seat the shank so it can still move
Isolate the mains or take the battery off before you change the bit. Wipe the shank. Grit in the grooves makes the next chisel stick. Put a light coat of shank grease on the shank only, not on the cutting edge. DeWalt’s booklet for the DCH735 and DCH775 family says clean and lightly grease, then insert until the bit can still move. We are not copying a gram weight from that PDF. Your own hammer’s booklet still wins if it names a grease.
Push the chisel in until it locks, then pull it. You should feel several centimetres of axial movement. That slide is the blow: the striker has to hit the end of the shank. A rigid shank is not seated, or it is the wrong system. If you are not sure the chuck is 18 mm SDS max rather than 10 mm SDS Plus, read SDS max versus SDS Plus before you force it.
Hammer-only, both hands, no lever
Turn the selector to hammer only, which is rotation stop. A chisel in rotary or rotary-hammer mode spins, the edge skates, and the shank can snap. The DeWalt booklet for that family says not to use those modes with a chisel. Use both hands and let the hammer’s weight do the work, with the steel in line with the tool.
Side load is what breaks a long chisel. A 400 or 450 mm flat is useful on a floor until you pry sideways. That length becomes a lever on the shank. Reviews across these listings include snapped pieces and a shank that broke in the chuck. If a slab will not move, change the tip or break a smaller piece. Do not stand on the hammer. On a chase, assume a cable or a pipe until you have located services. A point starts concrete. A wide edge gets under a tile. The wrong edge in the right mode still punches a hole you did not want.
Dust, noise, and time on the trigger
Concrete, mortar and many tile beds produce respirable crystalline silica. HSE’s workplace exposure limit is 0.1 mg/m³ over eight hours. Chasing, and a breaker in a poorly ventilated room, are the high-dust jobs. The control in that guidance is H or M class extraction plus respiratory protective equipment at assigned protection factor 20, a suitable FFP3, not a paper comfort mask. Indoors, extraction and RPE come before the first minute.
Gloves do not block vibration. At work, the Control of Vibration at Work Regulations 2005 set an action value of 2.5 m/s² A(8) and a limit of 5 m/s² A(8). INDG175 illustrates that a hammer-action tool may reach the action value in about 15 minutes and the limit in about an hour. That is not a reading for your chisel. It is a reason to plan breaks and keep the edge sharp.
Stop and check the edge
Stop when the edge has rolled, mushroomed or gone dull. HSE’s vibration pages say not to keep a blunt breaker chisel in use, because the hammer then runs longer for the same break. A sharper version of the wrong tip will not fix the job.
Stop for a structural opening, steel you cannot identify, or services you have not traced. The same handoff applies to hours on a breaker with no extraction and no plan for vibration.
Common questions
Which mode should the hammer be in?
Hammer only, with rotation stopped. A chisel in rotary mode spins and the shank takes a side load. Set the dial before you pull the trigger. If the tool has no hammer-only position, it is the wrong hammer.
Do I grease the cutting edge or the shank?
Grease the shank, lightly, after you wipe the grit off. Grease on the cutting edge flings oil at the work. No listing here states a gram dose. Lightly, as in the DeWalt booklet for that model family, is the level unless your own manual says otherwise.
The chisel slides in and out. Is it loose?
A few centimetres of movement after the shank has locked is the float the blow needs. Loose means it never locks, falls out, or will not enter because it is 18 mm in a 10 mm chuck. Pull the collar back and check the marking.
Why did the shank snap in the chuck?
The usual cause is side load. Levering a 400 mm chisel, leaving rotation on, or pushing a blunt edge does the same. Strike in line with the hammer. If the piece will not move, break a smaller section or change the tip.
What mask is enough for indoor concrete?
For concrete chasing, and for a breaker in a poorly ventilated room, HSE’s guidance is H or M class extraction plus RPE at assigned protection factor 20. That is an FFP3 used as instructed, not a thin comfort mask. The silica limit is 0.1 mg/m³ over eight hours.
Do gloves stop the vibration?
No. Gloves can protect skin. HSE does not treat them as the control for hand-arm vibration. A sharp chisel, hammer-only mode, breaks and less time on the trigger are what change the dose. The 15-minute line in INDG175 is a general example, not a reading for your bit.
Related pages
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.
- Heller Tools, SDS shank guide (retrieved 22 October 2026)
- TEH Tools UK, SDS Plus vs SDS max (retrieved 22 October 2026)
- HSE, INDG175 hand-arm vibration (retrieved 22 October 2026)
- HSE, vibration controls (retrieved 22 October 2026)
- HSE, construction dust CIS36 (retrieved 22 October 2026)
- HSE, PUWER overview (retrieved 22 October 2026)
- Consumer Rights Act 2015 (retrieved 22 October 2026)
- Bosch Professional GB, flat chisels (retrieved 22 October 2026)