Masonry Bits

A masonry bit isn’t a sharper version of a wood or metal bit. It works on a different principle. A masonry bit has a blunt, reinforced carbide tip that crushes material, while wood and metal drill bits are sharp and cut through material. Instead of slicing ribbons of material away, it functions like a tiny chisel — pulverizing the substrate on impact while the flutes auger the resulting dust out of the hole.

That’s why a standard twist bit fails the second it touches concrete. And it’s why two decisions matter more than anything else when you buy: matching the bit’s shank to your tool’s chuck, and matching the bit’s head to the material you’re drilling. Get either one wrong and you end up with a snapped bit, a burned-out drill, or an oversized hole that ruins every anchor you drive into it.

How the Bit Is Built and Why It Matters

Three parts do the work. The carbide tip — tungsten carbide is exceptionally resistant to heat and abrasion. On impact, the tip fractures the masonry into dust rather than dulling against it. A piece of tungsten carbide is brazed to the tip. The carbide is extremely tough and wear-resistant, enabling the bit to hammer its way through masonry or stone.

The brazing is where cheap bits fail. The carbide tip is bonded to the steel shank under high heat, often with copper or silver alloy. Premium bits use diffusion bonding or solid-carbide heads, which won’t shear off when the tip strikes rebar — a common failure point on cheap bits.

Then the flutes. The spiral grooves behind the tip exist purely to evacuate dust. U-flutes handle standard debris removal; deeper or variable flutes are used on bits designed for deep holes, where packed dust is the main cause of overheating and binding.

One thing to be clear on: you need the right tool to drive these. You can make a hole in soft masonry materials like brick using a regular drill, but it’s slow and inefficient. Use a hammer drill set to hammer drill mode. A standard drill spinning a carbide tip just generates heat without fracturing anything.

Shank types — the first decision

Your bit’s shank has to match your tool’s chuck. Three options cover almost everything:

Shank	Fits	Hole range	Best for
Straight / hex	Standard 3-jaw chucks (hex also fits impact drivers)	Up to ~3/8”	Brick, mortar, light block
SDS-Plus	SDS-Plus rotary hammers	~5/32” to 1-1/8”	Serious concrete work
SDS-Max	SDS-Max heavy-duty rotary hammers	~1/2” up to 2” or core sizes	Large holes, high-volume work

Straight or hex shanks fit standard 3-jaw chucks, and hex shanks also fit impact drivers. They’re suitable for holes up to about 3/8” in brick, mortar, and light block. Smooth straight shanks can slip under heavy torque; hex shanks grip better.

SDS is the system that changed concrete drilling. The slotted shank lets the bit slide independently of the chuck, transferring the hammer’s full impact energy straight into the carbide tip. That slot system allows them to slide in and out of the drill chuck easily, reducing wear and increasing drilling power. Seating one is simple — line a modern SDS bit up with the drill’s chuck and insert it. If it doesn’t seat, turn the bit slightly in either direction until it does.

For the biggest holes, SDS-Max is for heavy-duty rotary hammers and holes from about 1/2” up to 2” or core-drilling sizes, with a substantially thicker shank for maximum energy transfer.

Western Building Center carries bit options across these systems, including a Bosch hammer drill bit set, an SDS-Plus rotary hammer drill bit set, a Milwaukee 7-piece hammer masonry bit set, and Rotozip multipurpose bits.

Match the Bit to the Substrate

Not all masonry is the same hardness, and that drives both the bit and the tool you reach for.

Brick and mortar. A standard red brick may have a compressive strength as low as 2,000 PSI, and mortar joints are softer still. A 2-cutter straight or hex-shank carbide bit in a standard hammer drill is plenty. Heavy hammer impact isn’t required and can actually shatter hollow cinder block or fragile vintage brick.

Poured concrete and stone. This is where Montana’s foundations and slabs live, and where a basic hammer drill runs out of muscle. Cured structural concrete can exceed 6,000 PSI, especially with hard aggregate like granite or quartz. This calls for an SDS-Plus or SDS-Max bit in a true rotary hammer — the reciprocating hammer action is what actually fractures dense aggregate, not the bit’s sharpness.

Reinforced concrete. If there’s any chance of hitting rebar, a standard 2-cutter bit will catch and potentially snap. You need a dedicated 4-cutter or solid-carbide rebar-rated bit.

There’s also a placement call to make on brick walls. Should you drill into the brick itself or the mortar joint? Mortar is softer and easier to patch if you change your mind later — fine for light loads like cameras or signage. But mortar lacks brick’s structural integrity, so for heavy loads like shelving, TVs, and ledger boards, drill into the center of the brick itself.

2-Cutter vs. 4-Cutter Heads

If there’s any chance of steel in the hole, this is the decision that determines whether your bit survives.

2-cutter bits have a single carbide insert. They drill fast in clean, unreinforced concrete or brick and clear dust efficiently. But if the edge catches a piece of rebar, it can violently lock up — snapping the tip or twisting the drill and your wrist hard.

4-cutter (quad-head) bits use a cross-pattern carbide tip. They drill marginally slower in clean material but cut through rebar instead of binding on it, and produce rounder, more accurately-sized holes — which matters for anchors with tight tolerances like wedge and drop-in anchors.

The practical recommendation for anyone doing anchor work: if you’re stocking a toolbox for anchor installation work, 4-cutter SDS-Plus bits in the common anchor sizes are the most versatile single investment you can make. As for diameters, hammer drill masonry bits typically measure between 3/16 inch to 1/2 inch in diameter.

Technique Is Where Most Bits Die

The bit gets blamed for failures the operator caused. A few rules keep both the bit and the hole right.

Let the tool do the work. Leaning your body weight into a rotary hammer doesn’t drill faster — it stifles the piston, reduces impact energy, and overheats the bit. Apply firm, steady pressure and let the blows per minute fracture the material.

Watch your speed in soft material. Soft brick and mortar drill best at 400–600 RPM. Running at full speed generates excess heat that can melt the brazing holding the carbide tip on. For most masonry, aim for about 1,000 RPM or less to avoid overheating the bit.

Clear the dust. For holes deeper than about 2”, pull the spinning bit partially out of the hole every few seconds to clear the flutes. Packed dust is the number one cause of overheating, binding, and snapped bits.

And finish the hole right. Always drill 1/4”–1/2” deeper than the anchor’s embedment so settled dust doesn’t stop the anchor from seating flush. Then blow out every hole — dust left in the hole acts as a dry lubricant and significantly reduces anchor holding power.

A couple of mistakes worth naming, because they kill bits fast. Drilling concrete in rotary-only mode is one — without the hammering action, the carbide tip simply spins against the aggregate, generating heat fast enough to glow red and melt the brazing. The other is water: diamond core bits need water cooling, but standard carbide-tipped hammer bits don’t. Water turns concrete dust into an abrasive paste that packs the flutes and can thermal-shock a hot carbide tip into micro-fracturing. Never run water with an SDS bit in hammer mode.

Frequently Asked Questions

Can a regular drill bit go through concrete or brick? No. Using a regular drill bit on concrete or brick is not recommended. Standard bits aren’t strong enough to handle dense materials and can quickly become dull or break. A carbide-tipped masonry bit paired with a hammer drill is what these materials require.

Should I use my impact driver to drill into masonry? No. Don’t use your impact driver to make holes in masonry, which could burn it out. Chuck multi-material bits into a hammer drill instead to make a hole in brick, concrete, concrete block, mortar, or stone. Note that hammer mode on a cordless drill is a different thing than impact mode on an impact driver.

What’s the difference between a hammer drill bit and an SDS bit? Shank and tool. Round, tri-flat, or hex-shank masonry bits fit the 3-jaw chucks on standard hammer drills. Rotary hammer bits use specialized shanks sized to the tool’s system, most often SDS+ or SDS Max. SDS bits transfer hammer energy more efficiently, which is why they handle dense and reinforced concrete that a basic hammer drill struggles with.

What happens if I hit rebar? If you suddenly hit hard resistance and see metal shavings in the flutes, stop immediately. Switch to a 4-cutter or dedicated rebar bit, or relocate the hole. Pushing through with a 2-cutter bit risks snapping the tip and wrenching the drill.

How do I know when a bit is worn out? A dull bit requires more force to drill and overheats quickly. The signs are slower progress through the material, more pressure needed, and excessive heat. Once a carbide tip is shot, it’s time to replace it.

What’s the best single bit type to stock for anchor work? For anchor installation, 4-cutter SDS-Plus bits in the common anchor sizes are the most versatile single investment you can make. They cut through rebar instead of binding and produce the rounder, accurately sized holes that wedge and drop-in anchors need.