Hit rebar drilling into concrete?

Last updated: July 17, 2026

You've probably hit rebar, and the usual answer is to move the hole. Shift it over an inch or two to clear the bar and carry on — no special tooling, no structural question. You can drill through rebar with a rebar cutter bit run in rotation only (hammer off), but relocating is simpler and free, and it's the right first move for almost any DIY hole. Here's how to tell it's rebar rather than a stone, and what to do either way.

The honest version: hitting rebar is a stop-and-think moment, not a push-harder one. For almost any DIY hole, move the hole over to clear the bar — it’s free, and there’s no structural question to answer. You can cut through with the right bit, but going through means cutting reinforcement, and whether a given bar is safe to cut is an engineer’s call, not a web page’s. Never cut a post-tension cable — that’s a serious hazard, not a technique problem.

How to tell you've hit rebar (not just a hard stone)

You were drilling fine, then it stops dead. A few tells separate steel from a lump of aggregate:

• An abrupt stop at depth. Steady progress, then the bit stops advancing under the same pressure that was working a second ago.
• The bit spins or squeals instead of biting. The sound and feel change — a metallic ring or a slip, not the steady chatter of concrete.
• Metal in the dust. Look at what’s coming out of the hole: grey or shiny flecks and swarf mean steel; concrete gives a fine grey-white powder.
• It won’t yield. Hard aggregate (a stone) usually gives with patience and steady pressure; rebar doesn’t — it just stops you cold.

Rebar also sits at predictable depths, so if you’ve gone an inch or two into a slab or wall and hit a hard stop, steel is a likely culprit.

The default: move the hole

For most holes, shift over and carry on. Rebar is spaced several inches apart in a grid, so moving the hole an inch or two usually clears the bar and lands you in solid concrete — no structural question, no metal-cutting bit, no risk. If the exact position has any give, and for most DIY work it does, this is the answer. Most readers can stop here.

If you must go through: the two-step method

When the hole has to be exactly where the bar is, you can drill through the rebar. Before you do: going through means cutting reinforcement. If the bar might be structural, that’s not a call to make from here — stop and ask someone who can assess it. Relocating is free. And never cut a post-tension cable: in a post-tensioned slab the steel is under enormous tension, and cutting it is dangerous. If you don’t know whether a slab is post-tensioned, treat it as if it is.

The method has one crux — switch the drill out of hammer mode for the steel:

1. Drill to the bar with your carbide masonry bit and hammer drill, as normal.
2. Switch to a rebar cutter bit (or a cobalt HSS-Co bit) and turn hammer mode OFF — rotation only. Hammer action shatters a metal-cutting bit: the concrete gets hammered, the steel gets cut. Go slow, steady pressure, a little cutting fluid if you can.
3. Switch back to the masonry bit and hammer mode, and finish the hole.

Hammer plus rotation is for concrete; the bar needs rotation only. Leaving hammer on for the steel is what wrecks the cutter bit.

Rebar cutter bits (and why a masonry bit won't do it)

A rebar cutter is shaped to shear steel, with a different tip geometry from a masonry bit. A carbide masonry bit is built to pulverize concrete under hammer blows, not to cut metal, so on rebar it skates and burns. A cobalt (HSS-Co) bit cuts steel too. Either way the bit works by rotation, not percussion. Why the bit types differ is the wood vs metal vs masonry bit guide; which masonry bit to buy for the concrete itself is the concrete drill bit guide.

Avoiding it next time

Rebar sits at predictable depths and spacings, so you can find it before you drill. A rebar scanner, or even a cheap stud and metal detector, will flag the steel and let you place the hole to miss it. Worth it for anyone drilling more than a hole or two — it turns a stop-and-think moment into a non-event.

If the bit never got going in the first place — spinning on the surface with no bite — that’s a different problem: why your drill bit won’t go into concrete runs through it. This page is for when you were drilling fine and hit steel.