Wood Bits

A wood bit is a cutting tool built to bore holes in lumber without the wandering, burning, and tear-out that plague metal bits when you push them into wood. Drilling wood is different from drilling metal, and using the right bit type makes a huge difference — the hole quality, the noise, the tear-out on the exit side, and the speed all vary dramatically depending on which bit you pick.

Here’s the short version. Need a clean, precise hole for a dowel or cabinet hardware? Brad-point. Boring a big rough hole fast for cable or pipe? Spade. Going deep through thick timber? Auger. Flat-bottomed hole for a hinge? Forstner. Big circular opening for a lockset? Hole saw. Choosing the right wood drill bit ensures clean, accurate holes and faster work. Understanding their strengths helps you choose the best option for tasks like cabinetry, rough framing, deep boring, or precision joinery.

The wrong bit costs you material. Using the incorrect type of drill bit can also impact your drill’s performance and potentially damage the bit, the material, or even the power tool itself. Excessive heat generated by a dull or inappropriate bit can result in burn marks on the wood, and in extreme cases, can even cause the wood to catch fire due to the friction.

The Bit Types and What Each One Does

Six bit types cover nearly every wood job. They differ in hole quality, speed, size range, and how badly they tear out the exit side.

Bit Type	Hole Quality	Speed	Size Range	Tear-Out	Best For
Twist	Moderate	Slow to moderate	1–13mm+	Moderate to high	Pilot holes, general rough work
Brad-Point	Excellent	Moderate	1–16mm typical	Minimal	Cabinet work, dowels, furniture
Spade	Rough	Very fast	6–40mm	High (needs backing board)	Quick rough holes, cable runs
Auger	Excellent	Fast (self-feeding)	6–32mm	Minimal	Deep holes in thick timber
Forstner	Excellent (flat bottom)	Moderate	10–50mm	None (contained cut)	Hinges, partial and overlapping holes
Hole Saw	Good	Moderate	20–150mm	Low (contained cut)	Large openings, locksets, pipe

Twist bits are what most people picture when they hear “drill bit.” It’s the most common type of bit and is used for general purposes around the jobsite and home. They’re versatile but compromised in wood. They have two fluted spirals that eject chips as they drill. Twist bits don’t have a point to center the hole. Instead, they rely on one of the cutting lips to bite first, which can cause the bit to wander slightly. Once centered, they cut wood reasonably well, but the spiral flutes tend to pull fibers up on the exit side, creating tear-out. Fine for pilot holes where looks don’t matter.

Brad-point bits are the precision choice, and the difference is in the tip. They have a center point that keeps the bit perfectly centered, plus two cutting spurs that score the wood fibers before the flutes cut them away. That scoring action is the whole trick. When you score the wood fibers with the spurs, you sever them. Then, when the main cutting lips come through, there are no long fibers to tear—they’re already cut. This is why brad point bits leave clean, splinter-free holes. The sharp point on a brad point bit helps position the bit for a precise hole. These bits don’t walk on you when you start a hole. This makes this the right wood drilling bit for when you need a truly accurate start. Western Building Center carries Milwaukee brad-point bits in sizes including 1/8”, 3/16”, 7/16”, and 1/2”.

The trade-off is reach and durability. Typically 1–16mm; larger brad point bits are rare and expensive. The center point is delicate; hitting a knot can snap it.

Spade bits trade finish for speed. Spade bits have a broad, flat area for boring larger diameter holes in wood. The spade bit has no flutes, so you may have to back off the bit as you go when drilling deeper holes. They’re fast and cheap, but the exit side pays for it. Spade bits (or paddle bits) are flat, shovel-shaped bits with a center point and a sharp outer edge. They’re designed for speed, not precision. Use them for running wires or pipes through studs where the rough hole won’t show. The stock list includes Milwaukee spade bits in 1/2”, 9/16”, and 5/8” by 6”, plus a Demo Demon spade built to bore through nail-embedded wood.

Auger bits are the deep-boring workhorses. You’ll immediately notice a threaded tip on auger bits. This type of wood drilling bit uses the tip to quickly pull the bit through the wood. Auger bits maintain a constant flute throughout the length of the bit. That self-feeding tip and full-length flute make them long, spiral-shaped bits designed to drill deep holes in wood and remove material efficiently — exactly what you want for construction or large woodworking projects, structural woodworking or large builds, fence post installations. That last point matters in Montana, where treated fence posts and structural timber work are constant. Just keep the speed down — make sure the auger drill bit does not spin faster than 600 rpm.

Forstner bits do one thing nothing else can. These odd-looking bits bore through wood or create flat-bottomed holes if the hole doesn’t go all the way through the piece. Use them when setting up cabinet hinges or similar applications. They’ll also handle drilling overlapping holes and clean recesses in fine work. Western Building Center stocks Freud Forstner bits across a wide range — 1/4”, 3/8”, 1/2”, 5/8”, 3/4”, 7/8”, 1”, and up through 1-1/4”, 1-1/2”, 1-3/4”, 1-7/8”, and 2”. For maximum accuracy with these, use a drill press with Forstner bits.

Hole saws handle the big diameters. A hole saw uses a pilot twist bit to guide a large diameter rotary saw that removes a plug from the wood. This allows conduit or wires to pass through. You also use these bits when drilling out locksets for doors.

Two more worth naming, both in the stock list. Countersink bits earn their keep on finish work. The countersink drill bit is used to drill a pilot hole in the wood piece while also countersinking the screw. Countersinking will give an object a high-quality finish. Western Building Center carries Irwin countersinks. Plug cutters close the loop on hidden fasteners — plug cutters are used to cut plugs into the wood and then use those plugs to join two pieces together, giving the object a good finish. Irwin plug cutters come in 1/4”, 3/8”, 1/2”, and 5/8”.

Materials, Coatings, and Drilling Technique

For most wood work, high-speed steel does the job. High-speed steel: made from carbon steel with chromium and vanadium additives. It’s suitable for drilling wood, plastic and soft metals. The harder the wood, the harder the bit needs to be. The HSS drill bit can be used to drill softwood, but as the hardness of the wood increases, it must be matched by the drill bit’s hardness. A titanium or black oxide-coated drill bit is perfect for drilling hardwood.

The hardness gap is real. Match bit to wood species via Janka hardness: pine (softwood, 380 lbf) needs gentle bits; maple (hardwood, 1450 lbf) demands sharp carbide edges. Coatings each pull their own weight: black oxide: this coating helps drill bits retain lubricants and prevent rust from forming. TiN: a titanium nitrate coating that slows down wear and tear. For abrasive production work there’s carbide — carbide-tipped (as in Freud sets) for production, 90 Rc but brittle if dropped.

Speed matters as much as the bit. 500-2000 RPM for wood bits, slower for Forstners to avoid burning. Softwoods take the higher end of that range, hardwoods the lower, and augers stay below 600 rpm. Burn marks mean you’re going too fast or the bit’s dull. The flutes’ primary job is evacuating wood chips and sawdust from the hole that’s being drilled. The better the flute design, the faster it removes debris and reduces the likelihood of both overheating and jamming of the bit.

A backing board is cheap insurance against blow-out. Always use a backing board under the drill point. Place a scrap board underneath the bit and it will support the wood as the bit exits, preventing blow-out on the underside. Most important on spade and auger holes where tear-out runs high.

Shank choice comes down to your driver. The shank is the portion of the bit that fits securely into the drill’s chuck. Shanks come in various shapes — round, hexagonal, or triangular — to match the specific type of chuck on the drill and to prevent the bit from slipping when dealing with high torque levels. Hex-shaped shanks are particularly useful for ensuring a firm grip when drilling large holes that require more force. Round shanks chuck up standard; hex shanks resist slipping in impact drivers.

A few habits that keep bits cutting and fingers attached: secure the workpiece properly with clamps or a vise to prevent movement, reducing the risk of bit slipping or workpiece spinning. Keep drill bits sharp and clean; dull bits generate excessive heat and can cause tear-out, so regularly sharpen or clean with a brush or solvent. And store bits carefully in protective cases or racks to avoid damage, rust, and prolong their lifespan.

There’s a Montana wrinkle here too. Wood moves with the seasons — dry winters, more humid summers — and sloppy holes don’t hold up to that cycling. Wood “breathes” with humidity changes. Pine can swell 0.01 inches per foot of width for every 5% moisture gain. Drill a sloppy hole, ignore that breath, and your dowel joint fails seasonally. Clean, centered holes from a brad-point give dowel and drawer joints the fit they need to survive the swing.

Frequently Asked Questions

What’s the best all-around bit for clean holes in wood? Brad-point. The center point keeps it from wandering and the cutting spurs score the fibers before the flutes clear them, leaving splinter-free holes on both faces. Brad point bits have a sharp, pointed tip that ensures accurate hole placement. If you need a straight and clean hole, always opt for a brad point bit — it gives you pinpoint accuracy compared to other types.

Can I just use a regular twist bit for wood? You can, but you’ll fight it. Drilling into wood can be done with specially designed wood bits, or with regular multipurpose twist bits. If you are using a regular drill bit, you have to stop and clean out debris from the hole as you go along. Twist bits also wander on the start and tear out on the exit. Fine for pilot holes, less so for anything that shows.

Which bit do I use for cabinet hinges? A Forstner. Forstner bits leave clean edges and create flat-bottomed holes, making them popular among woodworkers. That flat bottom is what a concealed hinge cup needs to seat properly.

How do I stop the wood from blowing out the back of the hole? Clamp a scrap backing board tight against the exit side. It will support the wood as the bit exits, preventing blow-out on the underside. Slowing down as the tip breaks through helps too.

What speed should I run for deep auger holes? Keep it slow. Make sure the auger drill bit does not spin faster than 600 rpm. The self-feeding screw tip does the pulling — you supply light pressure and control, not RPM. Pair an auger bit with a low-speed drill for maximum control and clean results.

Do I need carbide bits for wood? Usually not. HSS handles most softwood and plenty of hardwood. Step up to a coated or carbide-tipped bit when you’re drilling dense hardwoods or abrasive engineered material, or running production volume — keeping in mind carbide is hard but brittle and doesn’t like being dropped.