Drill a screw into brick by matching three things: a carbide-tipped masonry bit sized to an ANSI standard, a minimum 1-inch embedment into solid material, and a clean, straight pilot hole. Use a hammer drill for the hole, but drive the screw with a standard drill or impact driver to avoid stripping the freshly cut threads in the brick.

The ANSI B212.The 15-1994 standard is the tolerance that decides whether your screw grips or spins freely. That specific number—not a generic “use a masonry bit”—is what separates a permanent mount from a repair job.

What follows is the breakdown of that standard, the exact embedment math, and the one tool switch professionals make that most DIY guides miss. By the end, you’ll know how to read any screw package and immediately know which bit and what depth it demands.

Key Takeaways

• The drill bit diameter is smaller than the screw. A 1/4-inch screw needs a 3/16-inch bit; a 3/16-inch screw needs a 5/32-inch bit, per ANSI B212.15-1994.
• Embedment depth is non-negotiable. Masonry screws must sink between 1 inch and 1-3/4 inches into the base material. Less than 1 inch provides near-zero holding power.
• Drive the screw with a rotary drill or impact driver, not the hammer drill. Using hammer mode while driving strips the threads you just cut in the brick.
• Drill into the brick for strength, the mortar for safety. Solid brick holds more weight, but old or fragile brick can crack. Mortar is softer and easier to patch.
• The hole must be deeper than the screw. Drill at least 1/4 inch deeper to create a dust chamber, or the screw will bottom out and refuse to seat.

The Specs That Aren’t Up for Debate

You can’t negotiate with brick. The numbers from manufacturer specs and engineering standards are the only rules that work. Get them wrong, and the project fails. It’s that simple.

A carbide-tipped masonry bit meeting ANSI standard B212.15-1994 ensures the correct tolerance between the drilled hole and the screw thread. For a 3/16-inch diameter masonry screw, use a 5/32-inch bit. For a 1/4-inch screw, use a 3/16-inch bit. The screw must embed between 1 inch and 1-3/4 inches into the base material.

The “blue screw”—typically a Tapcon brand masonry screw—is the default for a reason. Its hardened steel and aggressive thread are designed to tap into masonry. But the screw is only half of the system. The bit is the other half.

Using a standard twist bit or the wrong size masonry bit creates a hole that’s either too sloppy or too tight. A sloppy hole means the threads have nothing to bite, and the screw spins forever. A too-tight hole can’t be driven, or it cracks the brick from radial stress. The ANSI standard exists to prevent both.

Why the bit must be smaller: The screw isn’t a wood screw. It doesn’t displace material; it cuts threads into the sides of the hole. The bit creates the minor diameter of the thread. The screw’s threads are the major diameter. That difference is the grip.

Brick vs. Mortar: The Real Trade-Off

Your first decision is where to put the hole, with two targets: the solid brick unit or the mortar joint between bricks.Each has a specific failure mode.

Location	Best For	Risk If Chosen Wrong
Solid Brick	Heavy loads, structural fixtures, new/stable brick.	Cracking or spalling if drilled near an edge or into old, fragile brick.
Mortar Joint	Light to medium loads, easier patching, older walls.	Lower holding strength; unknown voids can cause fastener pull-out.

The Brick Industry Association notes that environmental exposure influences fastener material choice (corrosion), but the type of brick (solid vs. Hollow) determines the category of fastener. For solid brick, you’re typically using screws or sleeve anchors in the mortar joint. But a masonry screw can go directly into the brick face if it’s sound.

Drilling into mortar is undeniably easier. It’s softer. But that’s also the problem. Mortar’s compressive strength is lower. For a mailbox or a lightweight sconce, it’s fine. For a heavy shelf or a TV bracket, the brick itself is the only correct answer—provided you keep the hole centered and away from edges.

Where this goes sideways: Mounting a heavy object with deep holes in old, fragile brick. The expansion force of a sleeve anchor can create enough circular stress to crack it within days. If the bricks are already spalled, use the mortar or distribute the load across multiple bricks with a French cleat.

Tools: The Right One for Each Job

A hammer drill is non-optional for making the hole. A standard cordless drill lacks the percussive action to pulverize the masonry; you’ll burn out the motor and barely scratch the surface. A hammer drill combines rotation with a rapid hammering action to chew through the brick.

But here’s the part most guides get wrong.

You must switch tools to drive the screw.

Common mistake: Driving the masonry screw with the hammer drill still in hammer mode. The percussive action shatters the delicate threads you’re trying to cut in the brick, stripping the hole immediately. The screw will spin freely, and you cannot salvage the hole.

The professional method is clear: drill the pilot hole with the hammer drill in hammer mode. Then, insert the screw and drive it with a standard rotary drill or an impact driver. The steady, high-torque rotation of these tools allows the screw’s threads to cleanly cut into the masonry, forming a strong mechanical lock.

This is the difference between a one-minute install and a 30-minute repair that involves moving the fixture and drilling a new hole.

The 6-Step Process (And Why Each Step Matters)

This sequence works because every step solves the problem created by the previous one. Skip one, and you’ll discover the reason for it the hard way.

Step 1: Mark and Measure for Depth

Hold your fixture up and mark the hole. Use a center punch or nail to make a small divot so the drill bit doesn’t wander. This is about accuracy.

Now, do the math. The screw length must equal the thickness of your fixture plus a minimum of 1 inch of embedment. If your bracket is 1/2 inch thick, you need at least a 1-1/2 inch screw. Add another 1/4 to 1/2 inch to your drill depth for dust clearance. Mark this total depth on your drill bit with tape.

Why this matters: If the screw hits the bottom of the hole before the fixture is tight, it will either stop dead or snap. The dust chamber prevents that.

Step 2: Drill the Pilot Hole

Fit your hammer drill with the correct carbide-tipped masonry bit. Set it to hammer mode. Drill straight in, applying firm, steady pressure. Let the tool do the work; forcing it overheats the bit. Drill to your tape mark.

Why this matters: Drilling at an angle guarantees your fixture won’t sit flush. Overheating the bit blunts the carbide tip, making the next hole twice as hard to drill.

Step 3: Clear Every Bit of Dust

This is the most-skipped step with the most predictable result. Blow out the hole with compressed air, use a vacuum attachment, or run a wire brush in and out. Some pros keep the drill running as they pull the bit out to help evacuate dust.

Why this matters: Dust in the hole acts as a lubricant. The screw threads compact it instead of cutting into solid brick, reducing holding power by more than half. It’s like trying to screw into sand.

Step 4: Select and Insert the Screw

You have two head styles: hex washer head and flat countersunk. Hex heads sit above the surface and are driven with a socket or driver bit. Flat heads sit flush and need a Phillips drive. Match the driver size: #2 Phillips for 3/16-inch screws, #3 for 1/4-inch.

Step 5: Drive the Screw (With the Right Tool)

Switch to your rotary drill or impact driver. Place the screw through the fixture and into the hole. Drive it slowly at first until the threads engage, then at a moderate speed until the head is snug against the fixture.

Why this matters: Over-tightening is possible. You can strip the threads in the brick. Stop when you feel firm resistance. The screw should not spin.

Step 6: Set and Forget

Once tight, you’re done. A properly installed masonry screw shouldn’t need checking. If it feels loose during installation, the hole is likely too big or too dusty. The fix is to move over an inch and start again with a fresh hole.

The One Tool Mistake That Strips Brick Threads

We need to circle back on the driving tool because the consequences are instant and unfixable.

Manufacturer guides often just say “use a hammer drill.” They mean for drilling. But if you leave that hammer drill in hammer+rotation mode when you switch to the driver bit, you’ve just ruined the installation.

The mechanism is physical. The screw’s lead thread is cutting a helical groove in the brick. A steady rotational force shears a clean thread. The jackhammer action of the hammer drill shatters that groove into crushed powder. The screw advances, but it’s traveling through debris, not gripping solid material. By the time the head is flush, you can pull the screw out with your fingers.

The evidence is in the failed installations every pro has seen, and the fix is trivial: use the right tool for each phase.Drill with percussion, drive with rotation.

Troubleshooting: When It Doesn’t Go As Planned

Sometimes, despite best efforts, things go wrong. Here’s how to diagnose the common failures.

Symptom	Likely Cause	Immediate Fix
Screw spins freely, won’t tighten.	1. Hole too large (wrong bit). 2. Dust not cleared. 3. Embedment less than 1 inch.	Move location. Start over with correct bit size and thorough cleaning.
Screw won’t go in, driver stalls.	1. Hole too small (wrong bit). 2. Screw hitting bottom of hole. 3. Drilling into steel lintel or hard aggregate.	Verify bit size (5/32″ for 3/16″ screw). Check drill depth is 1/4″ deeper than screw. Use a metal-detecting stud finder first.
Brick face cracks or spalls.	1. Drilling too close to brick edge. 2. Using an expansion anchor in fragile brick. 3. Hammer drill setting too aggressive.	For old brick, switch to mortar joint or use a screw-in anchor like a masonry screw that creates less radial stress.
Screw head strips.	1. Wrong driver bit size/type. 2. Over-tightening with impact driver.	Use correct bit: 1/4″ hex driver for 3/16″ hex head, #3 Phillips for 1/4″ flat head. Drive until snug, not maximum torque.

If you strip a hole in the mortar, you can sometimes fill it with a two-part epoxy anchor compound and reset the screw. A stripped hole in the brick face is permanent for that location; your only option is to move over.

Frequently Asked Questions

Can I use a regular drill to drill into brick?

You cannot use a regular cordless drill to drill the pilot hole in brick. It lacks the necessary hammer action. You can and should use a regular drill to drive the masonry screw after the hole is drilled with a hammer drill.

How deep should I drill the hole for a brick screw?

Drill the hole a minimum of 1/4 inch deeper than the screw will penetrate into the brick. This extra space holds the dust created when the screw taps its threads, preventing the screw from bottoming out. A common rule is to add 1/2 inch to your required embedment depth.

What size drill bit for a #10 screw in brick?

10 screw is not a standard masonry screw size. Masonry screws are sized by diameter in inches: 3/16-inch and 1/4-inch are standard. If you’re using a #10 screw with a plastic wall plug in brick, you’d typically use a 6mm (approx. 1/4-inch) masonry bit with a red wall plug. For a true masonry screw, match the bit to the screw diameter, not a wood screw gauge.

Is it better to drill into brick or mortar?

It is better to drill into the brick for maximum holding strength and heavy loads, provided the brick is sound and not fragile. It is better to drill into the mortar for lighter loads, easier drilling, easier patching, or when working with old brick that may crack.

Can you screw directly into brick without a plug?

Yes, with a masonry screw (like a Tapcon). These screws are designed to tap threads directly into brick, concrete, or block, eliminating the need for a separate plastic wall plug or sleeve anchor. They require a precisely sized pilot hole.

The Bottom Line

Drilling a screw into brick breaks down to verified specs, not guesswork. Remember the three anchors: the ANSI-standard bit size, the 1-inch minimum embedment, and the clean, straight hole. Your hammer drill makes the hole, but your regular drill drives the screw home.

For the vast majority of outdoor fixtures and indoor heavy mounts, a 1/4-inch blue masonry screw into a solid brick is the default answer. If the brick is century-old and crumbly, pivot to the mortar joint without a second thought. The goal is to match the system to the material in front of you. Now you have the numbers to do it.