DeWalt 1-1/8 in x 31 in x 36 in SDS Max High Impact Quad 4‑Cutter Drill Bit

Why I reached for this bit

Deep anchor holes in structural concrete and pass‑throughs for rod or conduit aren’t friendly to undersized gear. For a recent round of installs—1-1/8-inch diameter holes, many of them 20–30 inches deep—I ran the DeWalt SDS‑Max bit with the 4‑cutter head. At 36 inches overall with a 31-inch working length, it’s built for that kind of reach. I paired it with a full‑size SDS‑Max rotary hammer and put it through slab, stem wall, and grade beam work, encountering both clean concrete and the occasional piece of steel on the way.

Build and design

The head is a high‑impact carbide 4‑cutter with an open‑head design. That geometry does a couple of practical things: the four cutting edges keep the hole round and help the bit stay centered as it advances, and the open crown directs dust into the flutes instead of letting it pack at the tip. The flute design is an elongated, milled four‑helix that’s aggressive enough to pull fines out of deep holes without constant babysitting. A hardened core runs the length of the bit for stiffness and breakage resistance, which matters with a 36-inch shaft when you’re pushing hard or working off a ladder. The SDS‑Max shank engaged cleanly in my hammer with no slop, and the etched size marking is a small but welcome detail when bits are covered in slurry.

Specs in brief:
- Diameter: 1-1/8 in
- Working/flute length: 31 in
- Overall length: 36 in
- Tip: carbide 4‑cutter
- Shank: SDS‑Max
- Weight: about 1.24 lbs

No case is included, so plan storage accordingly; long bits don’t like being tossed loose in a gang box.

Setup and compatibility

This is an SDS‑Max-only bit; don’t try to adapt it to SDS‑Plus. You’ll want a hammer with real impact energy—think pro-grade corded or high-output cordless SDS‑Max. I ran it on hammer-drill mode with moderate feed pressure, letting the hammer’s blows work rather than leaning my body weight into it. For deep holes, I started with a shorter 1-1/8-inch SDS‑Max bit to pilot the first 6–8 inches, then switched to the long bit to reduce wandering and lower the load on the flutes.

Clearance matters: a 36-inch bit means you need space behind the hammer for withdrawal and chip clearing. Overhead or corner work is possible but requires a steady hand to avoid side-loading.

Drilling performance in concrete

In plain, well-cured concrete, the DeWalt SDS‑Max bit cuts fast and runs steady. The 4‑cutter head bites immediately, so there’s little skating even on a rough start. The open-head design does what it claims: you can feel fines moving up the flutes rather than packing at the tip. That shows up as fewer stalls and smoother progress, especially in deep holes where chip evacuation makes or breaks productivity.

I measured time-to-depth on a series of 1-1/8-inch x 12-inch holes in 4000 PSI slab and averaged right where I expect a 4‑cutter to be—noticeably quicker than older two‑cutter designs I still keep around for abuse. On 24–30 inch passes, I made a habit of backing out every 4–6 inches to clear, and the flutes shed debris cleanly. Vibration levels were low for the diameter, with less chatter when re-entering the hole than I often see on long bits.

Hole quality is round and consistent. The four edges help prevent the door‑knocker effect you can get with two‑cutter tips when they catch aggregate. Breakthrough at the bottom is controlled; a slight easing of feed pressure in the last inch avoids spalling.

Encounters with steel

Every installer eventually finds steel. With tie wire and small bar (or the edge of a larger bar), the 4‑cutter head will tolerate brief contact and can nibble past if you don’t force it. That said, this is not a dedicated rebar‑cutting bit. When I hit #4 square-on in a grade beam, progress slowed dramatically and the blow feel changed from clean chipping to ringing. Easing off, indexing a few degrees, and letting the hammer tap didn’t get me through in a reasonable time. I either shifted the hole centerline or used a dedicated rebar cutter to punch the steel before returning to the DeWalt to finish the concrete.

If you regularly drill through rebar, plan your hole locations with a scanner and keep a rebar cutter or a combo system on hand. Pushing a masonry bit hard through steel shortens the life of the carbide and can chip the cutting edges.

Dust management

The open‑head is the right call on a long bit. With a vac attached to the hammer’s collar, fines pulled up the flutes rather than caking at the tip. In deep blind holes without vacuum, the bit still cleared well, but I kept the withdraw‑and‑dump rhythm to maintain speed and protect the carbide from abrasive slurry. For compliance, pair it with a HEPA vac and keep the operator in safety glasses, gloves, and hearing protection; 1-1/8-inch hammer drilling is loud and throws chips.

Durability and wear

After a run of anchors and a few deep penetrations, the cutting edges showed normal polishing with no chipping, and the braze line stayed intact. The hardened core helps keep the long shaft straight; I saw no perceptible whip unless I got sloppy with side pressure. As with any long bit, the risk isn’t snapping in pure axial drilling—it’s bending from prying or binding. Keep the hole aligned with the bit and avoid using it as a lever.

A quick wipe of the shank and a light film of oil before storage helps prevent corrosion. Without a case, I slide long bits into a length of PVC tube to keep them from getting dinged in transit.

Accuracy and technique tips

• Start with a shorter bit to establish the hole before switching to the long bit for depth.
• Let the hammer do the work; high feed pressure reduces chip flow and increases heat.
• Withdraw every few inches on deep holes to clear slurry and keep the flutes biting.
• Ease off near breakthrough to prevent blowout.
• If you hit steel, don’t force it. Shift, pre‑cut with a rebar cutter, or confirm you can move the hole.

The bit’s 31-inch working length is honest: you can get a true 31 inches of depth before the flutes disappear, which keeps chip evacuation viable nearly the whole way.

Who it’s for

If your work includes deep anchors, epoxy rods, through‑bolts, or service penetrations in structural concrete, this DeWalt SDS‑Max bit is sized right and built to keep pace. Facilities crews, concrete contractors, steel erectors, and MEP installers will get the most benefit. It’s overkill for SDS‑Plus hammers and the wrong tool for frequent, intentional drilling through rebar or steel‑heavy mat pours without planning.

Limitations

• Not a dedicated rebar cutter. It tolerates incidental steel but bogs down on full‑bar intersections.
• No storage case included.
• Requires a robust SDS‑Max hammer; underpowered tools won’t realize the bit’s potential and may stall.

The bottom line

The DeWalt SDS‑Max bit with the 4‑cutter head is a strong performer for large, deep holes in concrete. The open‑head and elongated four‑flute design make a tangible difference in chip evacuation, and the hardened core keeps the long shaft composed under load. It runs fast in clean concrete, produces round, consistent holes, and holds up well with proper technique. It’s not the answer for chewing through rebar every day, but paired with a scanner and a plan, it will carry most concrete drilling tasks at this diameter and length without drama.

Recommendation: I recommend this bit for anyone who needs reliable, efficient deep-hole performance in concrete with an SDS‑Max hammer. It’s especially good for installers who value speed and straight holes and who either avoid steel or are prepared to handle it with the right accessory. If your work routinely requires drilling straight through rebar, supplement this bit with a dedicated rebar cutter or choose a purpose‑built combo solution.