Rebar Drill Bits: How to Drill Through Rebar in Concrete Footings

What is a rebar drill bit?

A rebar drill bit is any bit made to get a hole through the steel reinforcing bar inside concrete. Three different tools are sold under that name: 4-cutter carbide hammer bits, rebar cutters (also called rebar eaters) and rebar punchers. They are not interchangeable, because each one needs a different drill mode. We stock all three for footing, grade beam and foundation wall work in our Foundation & Basement Repair shop, with the cutters and punchers grouped under Rebar Cutting.

Prices checked on eldoradotools.com on Oct 14, 2026. Each is priced per bit; the minimum order is shown when it is more than one.

"Rebar eater" is a trade nickname, and a brand name, for the rotation-only rebar cutter. If a supplier sells you a "rebar eater", check the description for the drill mode before you chuck it up.

Can you drill through rebar with a hammer drill?

Yes, you can drill through rebar with a hammer drill or rotary hammer, but only with the right rebar drill bit in the right mode. A standard two-cutter masonry bit stalls or chips its carbide when it meets steel. A 4-cutter X-Cutter and a rebar puncher both stay in hammer mode. A rebar cutter must run with the hammer switched off, because hammering shatters its carbide teeth against the bar.

"Hitting rebar while you drill concrete is rough on you. Catch it at the wrong angle and the tool twists hard and jerks your wrist. In my testing, a bit with rebar chamfers made a big difference: it takes the edge off that jolt, and drilling reinforced concrete feels a lot safer."

David Castro, President, Eldorado Tools

You do not need a rotary hammer to cut the bar itself. Our straight-shank rebar cutters fit a drill with a 1/2 in. chuck and run at 850 to 1,200 RPM, per ITM. That lets one person keep the rotary hammer in the hole while another cuts bar with a regular drill.

How do you drill through rebar in a concrete footing?

To drill through rebar in a concrete footing, drill to the bar, cut the bar with a tool sized to the hole, then finish the hole with the concrete bit.

1. Check before you cut. Footing and grade beam bar is structural. If the hole can move, shift it 1-1/2 to 2 in. and miss the bar. If it cannot move, get the engineer's OK before you cut steel.

2. Drill to the bar. Use the concrete bit in hammer mode. The bit stops advancing and the pitch changes when it reaches steel.

3. Clear the hole. Blow out the dust so the cutter starts on clean steel.

4. Cut the bar. Use a rebar cutter the same diameter as the hole, with the hammer off, at 750 to 1,000 RPM for an SDS-Plus cutter (ITM's range for the RBS-10). Keep steady, light pressure, keep the drill straight, and pull out often to clear chips. With a rebar puncher, leave the hammer on.

5. Finish with the concrete bit. Switch back, hammer on, and drill to depth.

6. Clean the hole. Blow, brush and blow again before you set an anchor or an epoxied dowel. Dust left in the hole costs holding strength.

Never drill concrete with a rebar cutter. It is made for the steel only, and aggregate wears its teeth in seconds.

Field tip: When the hole has to stay exactly where it's marked and the bit stops dead center on a #4 or #5 bar, a rebar puncher is the fastest way through. Leave the hammer on, punch the bar, then finish with the concrete bit, with no mode change and no waiting on a cutter. ITM rates its punchers best on #5 (5/8 in.) bar and under, so for #6 and heavier bar, switch to the rotation-only cutter. Keep one of each in the hole size you drill most.

Which rebar cutter size do I need?

Buy the rebar cutter or puncher the same diameter as the hole you are drilling, not the size of the bar. A 5/8 in. anchor hole that runs into #4 bar needs a 5/8 in. cutter. Every cutter and puncher below is sold individually.

Prices checked on eldoradotools.com on Oct 14, 2026, per piece, sold individually.

For deeper footings, the SDS-Plus punchers also come 18 in. long (for example RT-10-18, $93.66) and the SDS-Max punchers 21 in. long (for example RMX-10-21, $175.49). The straight-shank line adds an 18 in. 3/4 in. cutter, RBC1834 ($69.98). Browse them all in SDS-Plus Rebar Cutters, Straight Shank Rebar Cutters and SDS-Max Rebar Cutters.

What size drill bit do I need for rebar dowels in a footing?

For an epoxied rebar dowel, drill the hole a little larger than the bar so the adhesive can surround it. A hole 1/8 in. over the bar's nominal diameter is common, but your adhesive's installation chart is the rule. Bar diameters below follow ASTM A615.

Prices checked on eldoradotools.com on Oct 14, 2026, per bit.

The embedment depth comes from the drawings. Pick a bit whose drilling depth reaches it: drilling depth is shorter than overall length. The 3/16 in. x 8-1/4 in. X-Cutter (EVL81264, $10.10, min. 4), for example, drills 6 in. deep.

Should I use SDS-Plus or SDS-Max for footings?

Use SDS-Plus for footing holes up to about 1 in. and SDS-Max above that. Our SDS-Plus X-Cutters run up to 1 in. (EVL10001, 1 x 10 in., $52.93). For larger and longer holes, the SMTE3621 SDS-Max X-Cutter drills a 1-1/2 in. hole 31 in. deep ($292.75).

Rebar cutting does not force you back to a small hammer. The RMX rebar punchers fit SDS-Max and run in hammer mode from 5/8 in. to 1-3/4 in., so the big hammer that drilled the hole can punch the bar too. To reach through a deep footing, the XT6702 X-Tendr extension ($52.67) works with any SDS-Max bit, core bit or chisel; the cutting tool must be 1-1/4 in. or larger for the adapter to pass through the hole. See all SDS-Max tools.

For choosing concrete and masonry bits in general, see Types of Drill Bits Explained. For drill and bit speeds, see the Drill Speed Chart.

Questions about a job? Call our team at (833) 4-ETOOLS or email sales@eldoradotools.com.

Prices checked on the store on Oct 14, 2026.