The Diablo Rebar Demon 3/8-inch bit is a small-diameter bit from Diablo’s Rebar Demon line, a 4-cutter full-carbide hammer bit made for small anchor and fastener holes in concrete that may contain rebar. The Amazon listing is described as 3/8 inch in diameter and 13 inches long. Retailers list a bit of that size as an SDS-Max model (DMAMX1010), so confirm the shank on the Amazon page before ordering, because it only fits SDS-Max rotary hammers. The Diablo Rebar Demon 3/8 x 13 in drill bit is built for drilling reinforced concrete.
Diablo Rebar Demon 3/8-inch bit specs
| Spec | Detail (per Diablo and retailer listings) |
|---|---|
| Diameter | 3/8 inch |
| Length | 13 inches overall; one retailer lists 8 in. x 13 in. (working x overall) |
| Shank | SDS-Max on the matching retailer listing; confirm on Amazon |
| Head | 4-cutter full-carbide head with Dura-Carbide |
| Joining method | Tri-Metal Fusion Welding between carbide head and steel body |
| Tip and flutes | Precision tip and optimized flute design for dust removal |
| Heat claim | Carbide withstands up to 1800 F, versus 800 F for standard bits (manufacturer claim) |
| Weight and warranty | Not listed on the retailer pages checked |
What the Rebar Demon design is meant to do
Reinforced concrete is hard on drill bits. When a standard masonry bit hits steel rebar, the tip can overheat and chip. Diablo’s answer is a full-carbide head with four cutters that take smaller bites of rebar, a design Diablo says reduces vibration and spreads wear across the head. The head is attached with Tri-Metal Fusion Welding, which Diablo and retailers say makes the bond up to 3 times stronger than standard bits. Diablo also claims up to 7 times longer life; both are manufacturer claims and were not tested here.
The optimized flutes carry dust out of the hole, which helps keep the bit cooler and reduces binding.
Best uses for a 3/8-inch bit
- Small anchor and fastener holes in concrete or masonry.
- Pilot-size holes where rebar contact is possible.
- Hanger, bracket and conduit-strap holes, if the bit length suits your depth.
A 3/8-inch bit is not meant for large anchors. If your anchor spec calls for 5/8, 3/4 or 7/8 inch, see the larger Rebar Demon reviews: 5/8-inch DMAMX1090, 3/4 x 21-inch DMAMX1140 and 7/8-inch DMAMX1170.
How to get the best results
- Confirm the hole diameter and depth in your anchor instructions.
- Use a rotary hammer with an SDS-Max chuck. SDS-Plus and standard chucks do not accept this shank.
- Mark depth with tape or a depth stop, keep the hammer square and use steady pressure.
- Pull the bit back to clear dust and let it cool if it gets hot.
- Wear eye, hearing and respiratory protection, and use dust control. Concrete dust contains crystalline silica, which is a health hazard when inhaled.
- Scan for rebar, conduit and pipes before drilling in walls or slabs, and follow engineer guidance for structural members.
Pros and limitations
Pros
- Full-carbide, 4-cutter head meant for rebar contact.
- Precision tip and dust-clearing flutes.
- Small diameter for fastener and light anchor holes.
Limitations
- Needs an SDS-Max hammer if the listing matches the retailer model.
- A premium bit may be more than you need for a few holes in soft masonry.
- Weight, warranty and exact working length were not confirmed.
- Not hands-on tested for this article.
Frequently Asked Questions
What size is the Diablo Rebar Demon 3/8-inch bit?
The listing describes it as 3/8 inch in diameter and 13 inches long. A retailer lists a similar bit as 3/8 x 8 x 13 inches, but does not label the working length.
Is it SDS-Plus or SDS-Max?
The matching retailer listing says SDS-Max. Check the shank on the Amazon page and in your hammer manual before buying.
Can it drill through rebar?
It is designed for reinforced concrete and takes small bites of rebar, but it is still a concrete bit. Avoid cutting rebar when you can, and use a dedicated rebar cutter or move the hole when you hit steel.
Can I use it in non-reinforced concrete?
Yes. It works in plain concrete and masonry too, though a cheaper bit may be enough for light jobs.
What warranty does it have?
Warranty was not listed on the retailer pages checked. Check the Amazon listing and Diablo’s support page.
Bottom line
The Diablo Rebar Demon 3/8-inch bit is a heavy-duty small-diameter bit for anchor and fastener holes where rebar may show up. Verify the SDS-Max shank and length on the Amazon listing, and use it only with a compatible rotary hammer.
