Drill bits by material

Almost every bit failure is a material mismatch: a wood bit glowing dull in steel, a metal bit skating around a tile, a masonry bit polishing brick instead of punching it. Bits are cheap; knowing which one to load is the whole skill. This page covers one bit family per material, how to identify each at a glance from the tip, what it costs to choose wrong, and a chart to settle it fast. Cross-references throughout point to the drill side of the question: which of the 31 models in our comparison dataset actually has the mode and torque a given material needs.

The one-minute chart

Chart basis: ITS Hub drill bits buying guide; Home Depot drill bit buying guide; BAER on distinguishing bit types; BuildToolHQ drill bit selector.

The identification trick that carries most of this page: read the tip. BAER's guide makes the point that the tip answers the question immediately, because that is what contacts the material first. Center point, wood. Flat paddle, wood, fast and rough. Plain conical point, metal. Brazed silvery insert at the tip, masonry. Spear or arrow, tile. Gritty diamond rim, tile or glass. Hex shank with a flex section, impact rated.

Drill bits for wood

For holes up to about 1/2 inch, a brad point bit is the clean choice: the center spur locates the hole so the bit does not wander, and the outer spurs slice the wood fibers before the flutes remove material, which is what prevents tear-out at the hole edge. Home Depot's buying guide and BAER describe the same geometry. For rough framing speed over finish, a spade bit (a flat paddle with a center point) bores large holes fast but tears the exit side; back the workpiece with scrap to keep the breakout clean. For deep, large holes in timber, an auger bit with a self-feeding screw tip pulls itself through and clears chips up its deep spiral flutes; it wants a drill with real torque in low gear (see nail-embedded wood below for the variant that also survives hidden fasteners). For flat-bottomed holes at hinge recesses, that is a Forstner bit, used at low speed.

Choosing wrong in wood is a quality failure, not a safety one: a metal twist bit will bore wood acceptably but wanders on start and tears the exit, and hammer mode on any wood bit chews the cutting edges. Keep the clutch on a numbered setting when driving screws in softwood; our torque settings page covers which number.

Drill bits for metal

Mild steel, aluminum, brass, and plastic are HSS twist bit territory: high-speed steel with a conical 118 degree point. Because the tip has no centering spur, it will skate across a smooth surface unless you center-punch the spot first. Oil the hole when drilling steel; heat, not force, is what kills a metal bit. ITS Hub and the Home Depot guide both recommend low speed for mild steel and medium for aluminum.

One upgrade worth knowing: titanium-coated HSS (the gold-colored bits) is a thin PVD coating over ordinary HSS that lowers friction and wears in longer service, but it is a surface treatment; once the coating wears off the cutting edge the bit is plain HSS again, and sharpening removes the coating entirely. Cobalt is not a coating at all: the cobalt (5 percent in M35, 8 percent in M42) is alloyed through the whole bar, so a cobalt bit survives sharpening. Cobalt's real property is red hardness, meaning the edge keeps cutting at temperatures where plain HSS has already softened. Use plain HSS for mild steel and aluminum, titanium-coated HSS for general DIY life extension, cobalt when the material is the problem.

Drill bits for stainless steel and hardened steel

Stainless earns its own section because it fails bits differently: it work-hardens, meaning the surface gets harder as it is cut imperfectly, so a dull or too-fast plain HSS bit glazes the hole and then cannot bite at all. The consensus across the ITS Hub guide, the BuildToolHQ selector, and the cobalt-vs-titanium comparisons is the same recipe: an M35 or M42 cobalt bit with a 135 degree split point, very low RPM, and cutting oil, every time. Never a titanium-coated bit in stainless: the coating is gone after the first hard holes and the HSS underneath work-hardens the material further. A 135 degree split point (flatter than the 118 degree general-purpose point, with the web split so the tip self-centers) stops the skating that starts the work-hardening cascade in the first place. The full method, with RPM tables and the feed rules, is our how to drill through metal walkthrough.

Hardened steel (tool steel, spring steel, bolts) is harder than any HSS-family bit; the choices are M42 cobalt at its limit or a carbide-tipped bit, run slowly with oil and no wandering. If the bit has already blued from heat, the edge is dead; no amount of pressure recovers it.

Drill bits for brick and concrete

A masonry bit does not cut, it crushes: a brazed tungsten-carbide tip fractures the mineral material while the flutes haul out dust, which is why it belongs in a drill with hammer mode, where axial percussion does the fracturing. Home Depot's guide and BAER both describe the carbide-tip-plus-hammer-mode pairing; ITS Hub adds that using a masonry bit in rotary-only mode works but is much slower. Brick, block, and mortar joints are well within reach of any hammer drill: our hammer drill vs regular drill page lists verified blows-per-minute figures for five models in the dataset, from the $49.99 Bauer 59368 at 23,000 BPM to the DeWalt DCD999B at 38,250. For the diameter to load, the masonry bit size chart covers the inch and mm size runs for every shank type.

Concrete is a harder version of the same problem. Occasional small anchor holes in poured concrete are fine with a good cordless hammer drill and a quality carbide bit; repeated anchor work or holes approaching 1/2 inch in cured concrete belong to an SDS rotary hammer, whose electro-pneumatic mechanism delivers far harder individual blows. Our best drills for concrete page ranks the dataset's hammer-capable models for exactly this job. Masonry drilling is also the one place drill RPM matters least: the percussion does the work, and pulling the bit out periodically to clear dust matters more than speed.

Drill bits for tile

Tile is a brittleness problem, not a hardness problem. Standard ceramic tile drills with a spear-point carbide bit: the arrowhead tip bites the glaze and stops the bit skating (a strip of masking tape over the mark helps too), run slow, no hammer, ever. Porcelain tile, glass, and natural stone are harder and more brittle than ceramic, and diamond grit is the only thing that cuts them reliably: a diamond core bit, run slow with water to keep the grit cool. The BuildToolHQ selector and the ITS Hub guide draw the same ceramic-vs-porcelain line. Speed and percussion are what crack tile; the clutch's drill position plus low gear plus patience is the setup. For drilling glass specifically, the glass drilling guide has the full method; for speeds in other materials the drill speed chart has the RPM numbers.

Drill bits for nail-embedded wood

The remodeling reality: old studs and framing lumber have hidden nails, and a standard spade bit or wood auger hits one and instantly dulls or snaps. The bits built for this are nail-rated augers and self-feed bits, whose dual cutting edges and heat-treated tips are engineered to shear through embedded fasteners instead of folding: Diablo's Dura-Tip auger line and Bosch's Nail Strike sets are the established examples, documented on their product listings and in independent roundups. They are aggressive tools: a self-feeding screw tip pulls hard, so they want a high-torque drill in low gear with the side handle fitted, because the kickback from a jammed 3/4 inch auger is real. An auger of that size asks more torque than any 12V drill in our dataset delivers; this is high-torque 18V/20V territory, the class covered by the 1200 to 1400 in-lbs rows in the comparison table.

Impact driver bits vs drill bits

This family of searches folds into one question: an impact driver does not have a chuck, it has a 1/4 inch hex quick-change collet, so only hex-shank bits seat in it at all. Fitting is not surviving, though. Impact-rated bits have a torsion zone, a visibly necked-down flex section between the shank and the flutes that absorbs the tool's rotational hammer pulses before they reach the cutting edges; standard hex bits run straight from shank to flutes and snap at that transition under hard impact. The hex shank standard itself (1/4 inch across the flats) is cross-brand: any impact-rated bit fits any impact driver. The full family of hex driver bits, Phillips and Torx and square drive with their size codes, is cataloged on our screwdriver bit types page. A hex-to-chuck adapter lets an impact driver run ordinary round-shank twist bits for small holes in wood or sheet metal at light trigger pressure, but under full impact the round shank spins in the adapter jaws and non-impact-rated bits shear at the flute neck. The division of labor: driving fasteners and small holes, impact driver with impact-rated hex bits; larger holes, precision work, masonry, and anything on round shanks, the drill. Our impact driver vs drill page covers the tools themselves; this section is why their bits are not interchangeable.

Impact-bit basis: Tool Army Company, hex vs round shank; Engineer Fix, impact driver bits vs drill bits; True Tips on torsion zones.

How wrong choices fail

• Wood bit in steel: tip overheats within one hole, edge softens, then it is a painted nail. Heat is the killer; oil and slow RPM are the fix.
• Metal bit in tile: the conical point skates on the glaze and the tile cracks under the point load once it finally bites.
• Anything but masonry carbide in brick: the bit polishes the hole face and glazes; the drill strains, the bit burns.
• Hammer mode on a wood, metal, or tile bit: the percussion hammers the cutting edges against material they cannot crush, chipping the carbide or work-hardening the steel.
• Standard hex bit in an impact driver under load: shears at the flute neck with a crack, leaving a stub in the work.

What to own

A reasonable kit covers 90 percent of home work: a brad point set for wood, an HSS twist set for metal and plastic, a small masonry set for anchor holes, one spear-point tile bit, and impact-rated hex bits if you run an impact driver. Add cobalt and nail-rated bits when the job actually calls for them; drill bit coatings compared covers the black oxide, titanium, and cobalt question on those sets. The drill side of the equation, which model has the torque and hammer mode to drive these bits well, is what the comparison table with its 31 sourced models is for; the chuck sizes page covers the shank-diameter limits, and specs explained covers the torque and speed numbers. For how fast to run each bit in each material, the drill speed chart gives RPM by diameter for wood, metal, and masonry; for the driver bits that load into an impact driver instead, see screwdriver bit types. For the hole sizes screws want when they are not stripped, the pilot hole chart and tap drill chart are the references, and the bolt and screw extractor chart takes over when a fastener is already rounded or broken. For opening the finished hole to a precise size in thin stock, step drill bit sizes covers the stepped cones.