Do you ever catch yourself cringing just before drilling into rebar-reinforced concrete? “Is it another 15-minute hole?” is a common worry. Fingers crossed, maybe you’ll miss the rebar this time.
If not, what then? Do you press ahead and burn through a few bits? Call time out and grab a rebar cutter? It always comes down to time or money.
1,800 Degrees F
Creating a hammer drill bit that whips through rebar is a technology challenge. Metal on metal can create temperatures of up to 1,800 degrees F, far beyond most hammer drill bit capabilities. Even if the bit can take the heat, the difficulties of manufacturing limits bit selection to a few smaller diameters.
So what does an all-purpose rebar-killer look like? How do you manufacture them at popular prices?
Russell Kohl spends a lot of time thinking about those questions.
Kohl is president and CEO of Freud America, Inc., better known to REMODELING readers as Diablo, the power tool accessory solution providers. If you cut wood or metal, you know the name. Their tools are mainstays in wood and metal cutting.
Rebar-reinforced concrete? That’s another matter. To stick the landing there, Kohl and his team determined a rebar-busting drill bit would require an innovation hat trick:
- Lots of Carbide. Up to twice as much as the standard concrete drill bit and not just any carbide, either. They specified a proprietary carbide, called Dura-Carbide.
- 4-Way Cutters. Ordinary 2-way cutters are too coarse, bite too aggressively and generate way too much heat. Four-way cutting generates a smaller, more precisely engineered cut that reduces vibration and cuts cleaner, more precisely.
- Massively-Stronger Weld. The first two innovations are useless if the carbide shears off. A process called Tri-Metal Fusion Welding proves to be up to three times stronger than conventional welding.
Then for good measure, one more feature: “Price. It has to be a heavyweight drilling solution at the right price,” Kohl says.
Meet the Rebar Demon
Late this spring Diablo placed their bet: They introduced a full collection of SDS-Plus and SDS-Max Rebar Demon 4-cutter carbide head hammer bits, 75 in all. Diameters on the SDS-Plus side go up to 1-1/8-inch; on the SDS-Max side, up to 2-inches.
“Contractors can go through up to seven drill bits before they replace one Rebar Demon. Rebar Demon carves right through rebar. Just trust it. Let the bit do its job, even if your first impulse is to back off,” explains Kohl. A nice bonus is the usual tooth-rattling vibration mostly disappears.
The market response has been humbling, Kohl says. An early preview at this year’s World of Concrete drew enthusiastic crowds. The days since release affirmed the early reaction. “Contractors bought up 60 percent of our projected annual inventory in the first 30 days,” Kohl says.
Consider that good news for concrete contractors everywhere. Expect a lot less cringing around hammer drills this year.
Learn more about how to save time and money on drilling through rebar.