Types of Drill Bits and What Each One Drills Best

Updated September 2026 · Home Project Resources

The types of drill bits worth owning sort into eight families, and each family is defined by the material it cuts and the shape of hole it leaves behind: twist bits for general use, brad point for clean holes in wood, spade and auger bits for fast rough holes, Forstner bits for flat bottomed holes, hole saws for large openings, masonry bits for brick and concrete, step bits for sheet metal, and carbide or diamond bits for tile and glass. Choose the family by the material first. Size comes second.

The mistake that ruins the most parts is using a twist bit on tile or a wood bit on masonry. Neither one fails politely. A twist bit skates across glazed porcelain and cracks it, and a wood bit dulls into a smoking blue nub about ten seconds into a concrete block.

Updated September 2026

About to bore joists and drill a few hundred pilot holes for a deck? Use our free Deck Calculator to size the framing and the fastener list first, so you know exactly how much drilling is ahead of you before you buy a single bit.

The types of drill bits, family by family

Read that table by the second column. Most people shop by the picture on the package, and the picture almost never tells you what the bit is for.

Twist bits: the default, and their limits

A twist bit is the pointed spiral bit in every starter set. The tip grind is usually 118 degrees, which is a compromise angle that works in soft steel and wood alike. A 135 degree split point costs a little more and is worth it, because it self centers instead of walking across the surface before it bites.

Twist bits are sold by the metal they are made from, and that is the whole difference in price and life span:

In wood, a twist bit tears the entry and blows out the exit. Back the workpiece with a scrap board and the exit stays clean. In metal, the two rules are slow and wet: heavier pressure, lower speed, and a drop of cutting oil. Blue chips mean you are burning the edge off the bit.

Wood bits: brad point, spade, auger, Forstner

Brad point bits have a center spur and two outer cutting lips. The spur locks the bit exactly where you marked, and the lips slice the fibers around the rim before the flutes clear the waste. That is why the hole edge comes out crisp instead of fuzzy. Use them for dowels, shelf pins, and anything visible.

Spade bits are flat, cheap, and fast. They are made for holes you will never see, like running cable through studs. They wander if you start them off center and they tear the exit badly, so drill until the point pokes through, then finish from the other side.

Auger bits have a threaded lead screw that pulls the bit through the wood. That self feeding action is why they are the right choice for deep holes in thick timber, and it is also why they will yank a corded drill out of your hands if the bit binds. Use the side handle.

Forstner bits cut a flat bottomed hole with almost no tearout, because the rim scores the circle before the cutters clear the middle. That is the bit for a 35 mm cabinet hinge cup, for a partial depth hole that has to hold a magnet or a threaded insert, and for overlapping holes along a curve. They cut slowly and they make heat, so run them slow and back out to clear chips.

Hole saws cut a ring rather than the whole hole, so they can go big without a big drill. Keep the pilot bit sharp, clear the plug often, and drill halfway from each face on a door so the veneer does not blow out.

Masonry, concrete, and which drill you need

A masonry bit has a brazed carbide tip that is wider than the flutes. It does not slice, it pulverizes, so the drill has to hammer while it spins. Three tiers of tool exist and they are not interchangeable:

1. A standard drill with a round shank masonry bit. Fine for mortar joints, soft brick, and small anchors in block. Slow and tiring in poured concrete.
2. A hammer drill with the same round shank bits. The chuck vibrates in and out. It gets 3/16 in and 1/4 in holes into concrete without much drama.
3. A rotary hammer with SDS-plus bits. A piston drives the bit, so the tool does the work. SDS-plus covers most home anchor sizes. SDS-max is for demolition and holes over about 3/4 in.

The shank slots are the tell. SDS-plus has two closed slots and two open ones and snaps into the tool without a chuck. SDS-max is fatter, with three open slots. An SDS bit cannot go in a keyless chuck and a round shank bit cannot go in an SDS tool.

Anchor sizing is where people go wrong. Concrete screws are named for the screw diameter, not the hole diameter, and the bit is always smaller:

Drill the hole about 1/2 inch deeper than the fastener will go, then blow and brush the dust out. Dust left in the hole is the single most common reason a concrete anchor spins instead of grabbing. If you are drilling into a brick wall to hang something, our guide on how to hang a TV walks through the anchor choices in more detail.

Metal, tile, and glass

Step bits are cones with stepped cutting edges. In sheet metal, they deburr as they go and one bit covers a dozen sizes, which is why electricians keep one in the pouch for knockouts. They are for thin stock only, roughly 1/8 inch and under.

Tile bits come in two shapes. A spear point carbide bit handles glazed ceramic and glass. Porcelain is harder and abrasive, so it wants a diamond bit: either a small diamond core bit for anchor holes or a diamond hole saw for a shower valve or a pipe. Both want three things: a slow speed, no hammer action, and water. Park a blob of plumber's putty around the mark, fill it with water, and drill through the puddle. Start the bit at a slight angle so the tip cannot skate, then bring it upright once it has scored a ring.

If a whole floor is on your list, our step by step on how to tile a floor covers layout and cuts, and it pairs with these bits for the valve and drain penetrations.

Pilot holes: the chart that prevents split wood

A pilot hole should match the root diameter of the screw, the solid core the threads stand on. Too small and the wood splits. Too big and the threads have nothing to bite.

The clearance hole is a detail worth knowing. Drill the top board at full screw diameter so the threads pass through it freely. Then the head pulls the joint tight instead of jacking the two boards apart. Our guide to types of screws explains which fastener belongs in each of those holes.

A worked example: a deck ledger and 200 pilot holes

Say you are attaching a 20 foot ledger board to a house rim joist, then building a 20 x 12 foot deck on top of it.

The ledger. Code typically calls for 1/2 inch lag screws or structural screws in a staggered pattern. For 1/2 inch lags in softwood framing, the chart says a 5/16 inch pilot in the rim joist and a 1/2 inch clearance hole through the ledger. Two rows of fasteners roughly every 16 inches across 20 feet is about 30 holes, and each one is two different bits. A 1/2 inch auger or a long twist bit gets you through the ledger, and a 5/16 inch bit continues into the framing.

The framing. Joists at 16 inch centers across 20 feet is 16 joists. If you are running a receptacle or low voltage lighting through them, that is 16 holes with a 3/4 inch auger or spade bit, drilled in the middle third of the joist depth.

The decking. Roughly 240 square feet of surface, boards over 16 joists, two screws per board per joist. That is several hundred driven fasteners. Deck screws with an auger tip do not need pilot holes in the field, but the last 4 inches of every board does, because that is where boards split.

The bits that actually leave the truck: one 1/2 in twist or auger, one 5/16 in twist, one 3/4 in spade or auger, one countersink for the trim, and a 3/16 in carbide bit if any part of the ledger lands on masonry. Five bits, one deck. Get the deck size and fastener count first with the Deck Calculator, and the bit list falls out of it.

Speed, pressure, and how bits actually die

Bits do not usually break. They overheat, lose their edge, and then you push harder, and then they break.

The size rule is simple: the bigger the bit, the slower it turns. A 1/16 inch bit can spin at full trigger. A 2 inch Forstner should be crawling.

One more thing about impact drivers. A 1/4 inch hex shank bit is not automatically impact rated. Standard bits with a hex shank can shatter under the hammering action of an impact driver, so match the bit to the tool and keep the twist bits in a drill. If you are still building out a kit, our list of essential DIY tools sorts what to buy first.

Storage and sharpening

Loose bits in a drawer bang against each other and dull the cutting edges before they ever touch wood. An index case is not a luxury, it is what keeps a sharp bit sharp.

HSS twist bits can be resharpened on a bench grinder or a bit sharpener, and it is genuinely worth doing for anything 1/4 inch and up. Coated bits lose the coating at the tip when you regrind them, which is fine, they just go back to plain steel performance. Carbide masonry tips can be touched up on a diamond wheel. Diamond and step bits are consumables, so run them cool and wet and replace them when they stop cutting.

A quick honesty test: set the bit on a scrap board and turn it by hand with light pressure. A sharp bit shaves a small curl. A dull one polishes a shiny spot.

FAQ

What drill bits do I need for a basic home kit?

A twist bit index from 1/16 to 3/8 inch, a handful of masonry bits in 3/16 and 1/4 inch, a 1 inch and 2-1/8 inch hole saw for door hardware, a spade bit set, and a countersink. That covers hanging shelves, mounting hardware, and running the odd cable. Add brad point and Forstner bits when you start doing visible woodworking.

Can I use a wood bit in metal or drywall?

In drywall, yes, almost anything cuts it, though a jab saw or a hole saw is faster for boxes. In metal, no. A brad point or spade bit has a fragile spur that snaps in steel, and the tip geometry is wrong for the material. Use an HSS or cobalt twist bit with oil, or a step bit for thin sheet.

What is the difference between a hammer drill and a rotary hammer?

A hammer drill vibrates its chuck to add a light tapping action, and it takes normal round shank bits. A rotary hammer uses a piston to strike the back of an SDS bit, which delivers far more energy per blow. For a few anchors in block, a hammer drill is fine. For repeated holes in poured concrete, a rotary hammer is a different experience entirely.

How do I drill porcelain tile without cracking it?

Use a diamond bit, not carbide, and turn the hammer function off. Mark the spot, build a small dam of putty and fill it with water, start the bit tilted about 30 degrees so it scores a crescent, then stand it upright. Keep it slow and keep it wet. Rushing the last 10 percent of the hole is what blows out the back of the tile.

Do I really need a pilot hole for every screw?

No. Modern deck and construction screws with an auger tip drill their own path in softwood. You still want a pilot hole in hardwood, in anything within a few inches of an end or edge, in thin stock, and for every lag screw without exception. A lag screw driven dry into a joist will split it.

Why does my drill bit wander before it bites?

Either the tip angle is a standard 118 degree grind, which is prone to walking, or the surface is hard and smooth. Fix it three ways: punch a divot with a center punch first, switch to a 135 degree split point bit, or start the hole at a very low speed with light pressure until it scores a ring.

What size hole can I drill through a stud or joist?

In a bearing wall, a bored hole in a stud should not exceed 40 percent of the stud width, so about 1-3/8 inches in a 2x4. In a joist, keep holes out of the top and bottom thirds, at least 2 inches from the edges, and no larger than one third of the joist depth. Before you drill anything in a wall, check whether it is structural with our guide on how to tell if a wall is load bearing.