DeWalt 1-1/8" x 10" x 15" SDS-Max High Impact Quad Drill Bit

Why I reached for this bit

Large-diameter holes in concrete aren’t glamorous, but they’re a reality on many jobs—running conduit, sleeve penetrations, drain lines, and retrofit anchors often land in the 1-1/8-inch range. I’ve been using this DeWalt SDS‑Max bit for exactly those tasks, primarily in 4,000–5,000 PSI cast-in-place concrete and CMU block. Over several weeks, it handled through‑holes in 8-inch block, a handful of slab penetrations, and some overhead drilling. What stood out was a mix of steady speed, clean hole geometry, and low drama—no chatter, no flutes clogging, and no unexpected tip damage.

Design and build

The bit uses a four-cutter carbide head with an open-face design that feeds dust directly into the flutes. The helix is an elongated four-flute pattern that’s deeper than many general-purpose bits, and the core is visibly stout. On paper, that combination aims to do three things: increase contact area to reduce point loading, clear dust quickly to avoid binding/heat, and resist torsional breakage when the hammer hits hard aggregate.

Specs-wise, it’s a 1-1/8-inch diameter with a 10-inch working/flute length and a 15-inch overall length. Mine weighs right around 1.24 pounds, and the SDS‑Max shank locked up tight with no perceptible play in two different rotary hammers. The size etching is easy to read after use, which matters more than it sounds—once a bit rack has a few 1-inch-plus tools with worn paint, clear markings save time.

There’s no case included. That’s standard for pro masonry bits; I keep a length of vinyl tubing in the truck to protect the carbide in transit.

Setup and compatibility

This is an SDS‑Max shank, so it’s intended for larger rotary hammers. If your drill is SDS‑Plus, this isn’t your bit. On a mid-to-large SDS‑Max hammer, the balance feels right for its length. The 10-inch working length covers most through‑holes in walls and many slab penetrations; if you’re consistently going deeper than 10 inches, plan on a longer bit or step to a core rig.

I ran it at typical hammer-drill settings with moderate pressure—no reason to lean hard with a hammer this size. The bit seated positively and ejected without sticking, even after extended drilling.

Drilling performance

• Starting bite: For a 1-1/8-inch bit, it centers confidently. There’s no self-centering spike, but the four-cutter head doesn’t skate around on broomed or troweled concrete. On polished surfaces or tight layout, a quick countersink with a smaller bit (say 3/8 inch) makes starting foolproof.
• Speed: In solid concrete, drilling is brisk and consistent. Compared side-by-side with other premium SDS‑Max quad cutters, this bit’s pace holds up well, especially as the hole deepens. The elongated flute seems to keep the debris column moving, so you don’t experience that mid-hole slowdown.
• Dust evacuation: The open-head and flutes work together. With a vacuum shroud attached to the hammer, dust management is excellent. Without extraction, I still found it cleared well—helped by pausing to feather the bit and let the flutes carry out fines on the way back.
• Vibration and tracking: It runs smoothly. You can feel the tool progressing through aggregate without big rpm swings or chatter, which helps maintain roundness and keeps the hammer from working harder than necessary.
• Exit breakout: On through-holes in CMU, breakout was modest and predictable. In poured concrete, backing the exit with a sacrificial board or easing off in the last half-inch leaves a cleaner shoulder.

Hole quality

The four-cutter geometry gives very round holes at this diameter, which matters for sleeve fit and sealant bonds. Anchors and sleeves seated evenly with consistent annular gaps. I measured minimal ovality on a few test holes in 5-inch slab—about what I expect from a quad head and better than many two-cutter bits in this size.

Durability

After multiple holes in cured concrete and block, the carbide edges remained sharp with only light polishing, and there was no chipping at the corners. That’s typically where large bits show wear first. The hardened core didn’t exhibit torsional twist or visible stress marks.

I did encounter small aggregate inclusions that made the hammer work. The bit plowed through without temper loss or head wobble. A quick note on rebar: a four-cutter head is more forgiving than a two-cutter if you brush steel, but it’s not a dedicated rebar cutter. If you anticipate intersecting a lot of bar, scan first and plan your path; don’t treat this as a steel-drilling solution.

DeWalt includes a wear mark on the head; if that’s still visible and a bit fails, there’s a manufacturer replacement policy, though exclusions can apply. Practically speaking, the wear mark also serves as a good reminder to retire a bit before productivity drops or hole diameter wanders.

Dust and heat management

Large-diameter dry drilling creates heat fast. The flute design helps, but technique matters:

• Use a vacuum shroud when possible; it increases cutting efficiency and keeps the hole clear.
• Pulse the trigger or feather the bit periodically on deep holes to break chips and keep the flutes moving.
• Avoid leaning into the tool; let the hammer do the work. Excess force only builds heat and risks carbide damage.

Following those habits, I saw no blueing on the flutes and only modest warmth after continuous use.

Ergonomics in real work

At 15 inches overall, this bit is long enough for most tasks without being unwieldy. Overhead drilling is never fun at 1-1/8 inch, but the cutting efficiency shortens time on the trigger, which you feel in your shoulders at the end of the day. The weight is manageable, and the smooth running reduces the micro-stalls that add fatigue.

Value and comparisons

In the premium SDS‑Max bit category, performance and durability are what you pay for. This bit sits right where I expect for a four-cutter pro tool: fast enough to justify its place in the kit and tough enough not to become a consumable after a few holes. Against other four-cutter options I routinely use, it holds pace on speed and feels slightly better at maintaining clearing in deep holes, likely due to the elongated helix. If you require maximum precision starts on slick surfaces, some cross-head designs offer a touch more initial stability, but the difference largely disappears once the cut begins.

The etched size marking, reliable shank tolerances, and that wear mark are small but appreciated touches that show up in day-to-day use. The lack of a case is a non-issue for me.

Limitations

• It’s SDS‑Max only. If your kit is SDS‑Plus, you’ll need a different bit or a different hammer.
• The 10-inch working length covers most needs, but deep penetrations beyond that will require a longer bit.
• Not intended for sustained drilling through rebar. Occasional contact is one thing; cutting steel is another.

None of these are faults so much as realities of the category, but they’re worth noting so you pick the right tool for the job.

Tips for best results

• For precise layout, start with a smaller pilot hole, then step up to 1-1/8 inch.
• Use dust extraction whenever possible—it’s faster, cleaner, and easier on the bit.
• Let the hammer do the work; avoid excessive feed pressure.
• Back the exit face to minimize breakout on through-holes.
• Keep an eye on the wear mark to decide when to retire the bit.

Recommendation

I recommend this DeWalt SDS‑Max bit for anyone who regularly drills 1-1/8-inch holes in concrete or block with a full-size rotary hammer. It combines a durable four-cutter head with excellent dust evacuation and a strong core, translating into fast, predictable drilling and long service life. The hole quality is reliably round, the bit tracks straight, and the flutes stay clear without constant babysitting. If your work often intersects rebar or demands deeper-than-10-inch penetration, there are more specialized options. For everything else in this diameter, this bit belongs in the case.