The Diablo DMAMX1290 1-1/4 in. x 8 in. x 13 in. Rebar Demon SDS-Max 4-Cutter Full Carbide Head Hammer Drill Bit is a heavy-duty masonry drilling accessory for large holes in concrete and reinforced concrete. This is a hammer drill bit designed for drilling concrete, concrete with rebar, brick, block, stone, and natural stone. Model Number: DMAMX1290. If you are setting anchors, coring larger openings with a rotary hammer, or drilling where rebar strikes are common, this is the kind of bit built for that abuse.

The headline feature here is the full carbide 4-cutter head. That matters because big-diameter holes in reinforced concrete can punish a standard 2-cutter bit fast. Diablo says this Rebar Demon design delivers up to 7X longer life versus standard 2-cutter hammer drill bits. In practical terms, that means fewer bit changes, less slowdown when you meet rebar, and more confidence that the bit will stay productive through repeated holes instead of getting chewed up early.

Diablo also calls out its Dura-Carbide build, with up to 2X more carbide and heat resistance up to 1800 degrees Fahrenheit, compared to standard bits that fail at 800 degrees Fahrenheit. That is not just a lab number. On the job, heat is what kills masonry bits when drilling deep, wide holes or when the carbide head keeps contacting dense aggregate and steel. More heat resistance helps the cutting head hold up longer in the kind of work that usually shortens bit life.

The Tri-Metal Fusion Welding is another detail worth paying attention to. On a large SDS-Max bit like this, the bond between the steel body and carbide head matters as much as the carbide itself. Diablo rates this weld up to 3X stronger, which is important when the bit is taking repeated hammering loads and occasional rebar impact. That stronger head retention is one of the reasons this bit is aimed at serious concrete drilling instead of light-duty occasional use.

Hole quality is also part of the design. The precision tip is intended to keep the bit stable at the start and during the cut, which helps when accuracy matters for anchor setting or when you need a clean, true hole in reinforced concrete. The optimized flute design is there to move dust out faster. Faster dust removal helps the bit run cooler and keeps drilling efficiency up instead of letting concrete dust pack into the hole and slow everything down.

In terms of size, this bit has a 1-1/4 inch diameter, 13 inch overall length, and 8 inch working length. That puts it squarely in the category for larger-diameter masonry drilling where smaller SDS-Plus accessories are not the right answer. The SDS-Max shank is optimized for use in corded and cordless SDS-Max rotary hammers, so this is a system-specific concrete drilling bit, not a general-purpose drill bit for standard chucks.

Who should buy it? Concrete contractors, general contractors, mechanical and electrical trades, anchoring crews, and anyone drilling larger holes in reinforced concrete with an SDS-Max rotary hammer. If your work regularly involves concrete with rebar and you are tired of bits that slow down, overheat, or lose their edge after a few hard holes, this bit is aimed directly at that problem. For occasional light brick drilling, it is more bit than most people need. For repeated structural concrete work, it is the right kind of overbuilt.

Diablo DMAMX1290 hammer drill bit for guys who actually hit rebar

The big win with this bit is simple: it is built to stay productive in reinforced concrete where cheaper bits start giving up.

• Who it's for: Pros using an SDS-Max rotary hammer for anchor holes, structural drilling, and repeated concrete work where rebar contact is likely.
• Why it stands out: The full carbide 4-cutter head, stronger welded construction, and dust-clearing flute design all target the real reasons large masonry bits fail.
• Worth knowing: This is an SDS-Max bit only, and it is a single large-diameter accessory. If you do light-duty occasional drilling, it is more specialized than you need. If you drill reinforced concrete for a living, it makes a lot of sense.

• What tools does this bit fit? It is designed for corded and cordless SDS-Max rotary hammers.
• Can it drill through rebar in concrete? Yes. This Rebar Demon bit is specifically built for concrete with rebar and uses a 4-cutter full carbide head for durability and controlled wear.
• What is the drilling depth? The working length is 8 inches, with a 13 inch overall bit length.
• What materials is it made to drill? It is intended for concrete, reinforced concrete, brick, block, stone, and natural stone.