Bosch 10 in SDS-plus Star-Point Twist Chisel

Why I reached for this chisel

Adjusting masonry openings and chasing narrow channels in cured concrete is where many chisels struggle: either they bind and glaze, or they remove too much material too quickly. I picked up the Bosch twist chisel specifically for those in-between tasks—where I need a precise break line and steady progress without constant re-sharpening. After several days of use on a mix of brick, mortar, and 4,000 PSI concrete, it’s become one of the few SDS-plus bits I keep in the hammer case by default.

Design and build

This is a 10-inch SDS-plus chisel with a star-point, twisted tip. The cutting edge is a narrow 1/2 inch, which keeps it on the precision side of demolition rather than bulk removal. The twist isn’t just cosmetic: it does two things well. First, it keeps the point self-sharpening, so the tip doesn’t mushroom into a blunt cone after an hour of hammering. Second, it creates a slightly wider material removal footprint than a standard bull point, which helps shed fines and reduces the tendency to jam in the cut.

The steel feels like typical Bosch Bulldog-grade hammer steel—tough and resilient without being brittle. After a few heat cycles in hard concrete, I didn’t see blueing or tip deformation, which is where cheaper chisels often show their limits.

Setup and compatibility

I ran the chisel in two SDS-plus rotary hammers: a compact 7/8-inch class tool and a beefier 1-inch class model, both in hammer-only mode. As expected for SDS-plus, it seats securely with minimal play. The 10-inch length is a sweet spot for control; it’s long enough to see the work and keep knuckles clear of the surface, but short enough that the bit doesn’t whip or amplify vibration.

If your hammer offers a Vario-Lock-style collar to index chisel angle, you won’t need it for this star-point geometry. Orientation is essentially neutral compared with a flat or spade chisel.

Performance in concrete

My first test was trimming a high spot along an interior slab edge and then channeling a shallow run for conduit. In cured concrete, the star-point initiates a break quickly without skating—fewer false starts than I typically get from a plain bull point. Once it bites, the twisted lands carry dust out of the strike area, so the tip keeps contacting fresh material. Progress felt steady and predictable.

Bosch claims a 15% higher material removal rate versus standard chisels and a 30% longer lifetime. I don’t have a lab to confirm percentages, but side-by-side against a well-used point chisel, this one was noticeably faster and stayed sharp longer. Where I usually pause to wire-brush glazing off the point, I didn’t need to with the twist tip.

On green concrete (early-age patch work), it’s even smoother. The bit doesn’t pack the tip with slurry as quickly, which means fewer stalls and less heat buildup.

Brick and mortar work

In brick, control matters more than raw speed, and this is where the 1/2-inch edge shines. Cleaning out mortar to widen an opening or nibble back a corner is straightforward with light pressure. The star-shaped point breaks the mortar cleanly without sending long cracks across the face of the brick. Compared with a flat chisel, you get less risk of spalling on the brick face, though you’ll remove material a touch slower. For tuckpointing or broad mortar removal, I’d still switch to a wider flat chisel; but for precision adjustments around openings, this twist chisel is the right pick.

Working around rebar and embedded hardware

Clearing around rebar is always a test of feedback. Some chisels grab and ricochet; others chip unpredictably when the tip kisses steel. With this bit, the contact felt controlled. It doesn’t dig into the bar, and the twist helps lift chips away rather than wedging. I could peel concrete off the sides of reinforcement with a series of short, shallow taps and minimal binding.

Vibration and control

SDS-plus chisels can be fatiguing in dense material. This one transmits vibration in a tighter, higher-frequency “buzz” rather than the thuddy oscillations I get with some flatter tips. It’s not silent, of course, but the feedback is useful—you can feel when you’re on aggregate vs. paste and adjust pressure. The 10-inch length helps keep the bit aligned; I didn’t fight walking or dancing on smooth surfaces nearly as much.

Durability and maintenance

After several hours in cured concrete and clay brick, the point remained crisp. The self-sharpening geometry is doing something right; the lands and valleys stayed distinct, and the tip didn’t round over. Shank wear was normal, with no burrs in the grooves.

A few care tips that helped:
- Keep the shank lightly greased to reduce heat and wear in the chuck.
- Let the hammer do the work—excessive side loading will shorten the life of any SDS-plus chisel.
- Clear dust from the cut frequently to preserve that self-sharpening action.

Where it excels

• Precision adjustment: Nibbling back a sill, trimming the edge of a chase, or fine-tuning openings in block and brick.
• Continuous cuts with less jamming: The twist design keeps the tip clearing fines, especially noticeable in green concrete and crumbly mortar.
• Working near reinforcement: Controlled chip removal without aggressive grabbing on steel.

Where it’s not the right tool

• Bulk demolition: If you’re breaking a slab or removing large sections of concrete, an SDS-max hammer and a wide flat or spade chisel will be far more efficient.
• Deep reach: At 10 inches, it’s comfortable for wall and edge work. For deep recesses or floor trenches, a longer bit may be preferable.
• Clean, straight grooves: If you need a flat-bottomed chase with neat walls, a narrow flat or tile chisel will finish cleaner than a star-point profile.

Practical tips for best results

• Start at a shallow angle to create a small divot, then steepen the angle to continue the break. This minimizes initial skating on smooth surfaces.
• Use lower impact settings on fragile brick to avoid spalling; increase as needed for concrete.
• Pause periodically to vacuum chips from the cut; you’ll keep progress smooth and heat down.
• Avoid prying with the bit to lift large chunks—SDS-plus shanks aren’t designed for sustained levering.

Value and alternatives

The Bosch twist chisel sits above generic bull points in price but earns its keep by staying sharp and moving material with less fuss. If you do mostly precision masonry work—mechanical penetrations, adjustments, conduit runs in residential remodels—you’ll likely reach for it often. If your work is heavy demo, skip straight to SDS-max and wider chisels. For finishing or flatter cuts, pair this with a 1- to 2-inch flat chisel and you’ll cover most small-job scenarios.

Recommendation

I recommend the Bosch twist chisel for anyone who needs controlled, continuous chiseling in concrete and brick with an SDS-plus hammer. It balances precision and productivity better than a standard point chisel, resists jamming thanks to the twisted tip, and holds its edge over long sessions. It’s not a replacement for wide flats in bulk removal or an SDS-max setup for heavy demolition, but as a precision workhorse in the SDS-plus kit, it’s a smart, durable choice.