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Plumbing and electrical pass-throughs are usually drilled in different materials, and that determines the right bit. A hammer drill bit is useful for brick, block, concrete, and some mortar joints. It is the wrong tool for wood studs, metal framing, tile surfaces, and most finished walls.
The best setup is often a small selection rather than one “do everything” bit: carbide-tipped masonry bits for anchors and small sleeves, longer SDS-Plus bits for thick masonry, and wood or metal bits for the framing after the masonry is penetrated. Choosing the bit by diameter and wall material prevents cracked masonry, overheated bits, and holes too small for the cable or pipe.
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Choose the Bit by Wall Material
Standard hammer-drill bits have a carbide cutting tip and work in rotary-hammer or hammer-drill mode. They are suitable for brick, concrete block, mortar, and lighter concrete work. The common round-shank versions fit a three-jaw chuck. SDS-Plus bits have grooves that lock into an SDS-Plus rotary hammer and transfer impact more efficiently.
| Wall or framing material | Best bit type | Typical use | Main limitation |
|---|---|---|---|
| Brick or concrete block | Carbide masonry bit | Small conduit, cable, and pipe holes | Can wander on hard glazed surfaces |
| Solid concrete | SDS-Plus hammer bit | Long or larger pass-through holes | Needs a compatible rotary hammer |
| Mortar joint | Carbide masonry bit | Small cable routes where permitted | Weak joints can crumble or enlarge |
| Wood stud or joist | Auger, spade, or self-feed bit | Pipe and cable holes through framing | Hammer mode will damage the bit and wood |
| Metal stud or plate | High-speed-steel twist bit or step bit | Conduit and cable openings | Requires edge protection and careful deburring |
| Tile over masonry | Tile bit first, then masonry bit | Finished backsplashes and bathrooms | Hammer action can crack the tile |
Best Bit Types for Pass-Throughs
For ordinary brick and block, a set of carbide-tipped masonry bits is the economical choice. A 3/16-inch or 1/4-inch bit handles small cable holes, while 3/8-inch to 1/2-inch sizes are more useful for small tubing and conduit. Buy several sizes because masonry quickly dulls the smallest bits when they are used at high speed.
For a larger hole, use a masonry core bit or a diamond core bit rather than forcing a long twist-style masonry bit sideways. Core bits cut a ring and leave a central plug, producing a cleaner opening for sleeves and conduit. They create more dust and need a drill with enough torque. Dry diamond bits can work on brick and block, but they are less forgiving in hard concrete and can overheat if pushed continuously.
When the wall is thick or the hole must be straight, an SDS-Plus masonry bit set is usually a better investment than extra-long round-shank bits. SDS-Plus bits commonly run from 5/32 inch through 1 inch and are available in lengths from roughly 6 to 18 inches. A compact rotary hammer drills concrete faster and with less pressure than a cordless hammer drill.
For wood framing, switch to an auger bit set for wood. A 5/8-inch or 3/4-inch auger is a common choice for cable bundles and smaller water lines. Spade bits cost less and drill quickly, but they leave a rougher hole and are more likely to catch when breaking through the far side. Never use hammer mode in wood.
Size the Hole Correctly
Do not size the hole to the outside diameter of a single wire or tube. Allow room for the actual cable bundle, conduit, insulation, movement, and a bushing or sleeve. For example, a 1/2-inch conduit may need a 5/8-inch or 3/4-inch hole depending on the fitting and wall thickness. A hole for a water line should not pinch the pipe; copper and plastic need clearance for installation and expansion.
For electrical cable through wood or metal, install listed bushings, grommets, or nail plates where the cable could contact an edge. Masonry holes can be sleeved with plastic or metal conduit. A rough hole without edge protection is a failure point: vibration can wear through insulation over time.
How to Drill Cleanly and Safely
Locate the hole with a stud finder, inspection opening, or the plans before drilling. Check both sides of the wall when possible. Avoid concealed plumbing and wiring, and do not drill near electrical outlets or switches without confirming the route. A 1/2-inch pilot hole is not a substitute for locating services.
On brick or block, start in rotary mode at low speed to establish the hole, then engage hammer action once the tip is seated. Moderate pressure works better than leaning hard on the drill. Withdraw the bit every few inches to clear dust. Packed dust reduces cutting, increases heat, and can wedge the bit in the hole.
On concrete, use a rotary hammer in hammer-drill mode for most pass-throughs. Stop if the bit hits steel. Repeatedly hammering into rebar can damage the bit, the tool, or the structure. Move the hole only when you have confirmed that shifting it is safe; do not cut structural reinforcement casually.
For tile, disable hammer action and use a tile or glass bit until it passes through the tile. Then change to a masonry bit and hammer mode only after the carbide tip is clear of the finished surface. Keep the bit cool and avoid excessive pressure, especially on porcelain.
What to Buy
A homeowner doing occasional cable routes can buy a six- to ten-piece carbide masonry set and a separate wood auger set. The cheaper option is fine when holes are under 1/2 inch, the wall is brick or block, and the drill is used only a few times. Replace a bit when the carbide tip is rounded, chipped, or visibly asymmetrical; sharpening inexpensive masonry bits is rarely worthwhile.
If you regularly drill concrete, need holes over 1/2 inch, or work through walls thicker than about 6 inches, choose an SDS-Plus rotary hammer and quality SDS bits. Spending more on the bit matters most in hard concrete, where poor carbide geometry can turn a five-minute hole into a stalled, overheated job. For one large pass-through, renting a rotary hammer and buying the correct core bit is often cheaper than abusing a compact cordless hammer drill.