Picking the right drill bit for wood makes the difference between clean, professional holes and splintered, wandering messes. Wood is forgiving compared to metal or masonry, but different bits are designed for different jobs—and using the right one saves time and frustration.
The Main Wood Drill Bit Types
Most DIYers and tradespeople will use three or four types of bits regularly. Here’s what each does and when to reach for it.
Twist Drill Bits (HSS or Carbon Steel)
The standard general-purpose bit. You’ve got a set of these already. Twist bits work fine for wood—they’re not as clean as brad point bits, but they’re quick, cheap, and versatile. The spiral flutes pull chips out as you drill, so you get decent clearance.
Best for: Pilot holes for screws, general drilling where appearance doesn’t matter, fast rough work. Sizes from 1mm up to 13mm commonly used in wood.
Speed: Fast—1500 to 3000 RPM for timber, depending on bit diameter. Smaller bits can go faster.
Downside: The pointed tip can “walk” when you start the hole, especially on hardwood. You’ll get some splintering on the exit side.
Brad Point Bits (Dowel Bits)
These are the clean-hole specialists. A brad point bit has a sharp centre point and two cutting edges that score the wood fibres before the main flutes remove the waste. Result: dead straight, clean holes with minimal splintering.
Best for: Dowel holes, cabinet work, through-holes where both sides need to look decent, hardwood drilling (oak, walnut, ash). Sizes typically 3mm to 12mm.
Speed: Slightly slower than twist bits—1000 to 2500 RPM depending on wood hardness. Harder wood = slower speed to prevent tearout.
How to use: Start slowly and let the brad point do the work. Once it bites, you can speed up. The point holds position, so no walking.
Amazon: Brad Point Bit Sets on Amazon UK
Spade Bits (Flat Bits)
Fast and rough. Spade bits are cheap, fast, and make large holes quickly. They have a flat blade with sharp edges and a centre point. Not elegant—they’ll leave tearout and splinters—but they’re brilliant for speed work like rough holes for plumbing or electrical runs.
Best for: Rough holes 10–40mm, drilling through timber joists and studs, speed is more important than finish, waste holes for cables and pipes.
Sizes: 4mm, 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, 32mm (common sizes). Larger sets go to 50mm.
Speed: Fast—2000 to 3000 RPM, even faster for small bits. These can handle speed because of their simple design.
Warning: Spade bits can bind and twist suddenly if they catch a knot or grain change. Keep a firm grip and use low torque settings on percussion tools (no hammer action).
Forstner Bits
Forstner bits create perfectly flat-bottomed holes with clean sides. They’re precision tools, used when the hole finish matters. No centre point—just a sharp rim that scores the perimeter while a flat base clears the waste. Perfect for cabinet work, dowel jigs, and inlay work.
Best for: Flat-bottom cavities for dowels, hinges, shelf studs, inlay work, drilling near edges (the rim doesn’t wander like a centre point). Sizes 15mm to 50mm most common.
Speed: Slow—500 to 1500 RPM. Forstner bits generate heat and can burn timber if run too fast.
Setup: Clamp your workpiece. Use a backing board underneath to prevent splintering on the exit side. Start drilling and let the bit do the work—don’t force it.
Amazon: Forstner Bit Sets on Amazon UK
Auger Bits
Long, spiral bits with a centre point and self-feeding design. Auger bits pull themselves into the timber, which means you need less downward pressure. They’re the go-to for deep holes in solid timber—drilling down through a 200mm stud or through the centre of a thick post.
Best for: Deep holes (100mm+), drilling through thick timber, hand brace work (many old braces accept auger bits). Sizes 6mm to 25mm typical.
Speed: Slow—500 to 1200 RPM. The self-feeding action does the work, so speed isn’t needed.
Downside: Expensive compared to twist bits, and you need the right chuck to grip them. They also tend to bind if you hit a knot.
Hole Saws
When you need a hole larger than your largest bit (say 20mm to 150mm), hole saws are your answer. They’re circular saw blades with a pilot bit in the centre. They cut a ring and leave a solid centre core.
Best for: Large holes for pipes, cables, mixer taps, door hardware. Sizes 16mm up to 150mm.
Speed: Slow to medium—500 to 1500 RPM depending on size. Larger saws = slower speed.
Setup: Clamp well. Use backing board underneath. The saw will want to rotate the workpiece if it catches, so secure it firmly.
Amazon: Hole Saw Kits on Amazon UK
Wood Type Matters: Softwood vs Hardwood
Softwood (pine, spruce, fir): Easy to drill. Twist bits and spade bits work fine. Brad point bits stay sharper longer because the wood is softer. HSS bits are fine.
Hardwood (oak, ash, walnut, maple): Denser and tougher on bits. Brad point bits are worth the investment because they prevent tearout on the exit side. Run bits slower than you would in softwood. Sharper bits (HSS or cobalt) stay sharper longer than carbon steel.
Speed and Setup Tips
Set Your Drill Speed Correctly
Most cordless drills have two speed settings. Use low speed for:
- Large bits (over 10mm)
- Dense hardwood
- Forstner bits
- Hole saws
- Deep holes
Use high speed for:
- Small bits (under 8mm)
- Softwood
- Brad point bits
- Pilot holes
Clamp Your Workpiece
Wood will rotate if the bit binds. Clamp it to your bench or a sawhorse. This prevents injury and splintering. If you’re drilling near an edge, use a backing board underneath to stop the exit side splintering.
Start Slowly, Then Speed Up
Let the bit establish itself before applying full pressure. A slow start gives the point time to bite. Once you feel the bit pulling itself in, you can increase pressure and speed.
Clear Chips Frequently
Stop occasionally and back the bit out to clear chips. This prevents heat buildup and lets you see your progress. Don’t let chips jam around the flutes.
No Hammer Action on Wood
Switch off hammer mode on your drill if you’ve got it. Hammer mode is for masonry. On wood, it just produces tearout and burns the hole edges.
Bit Size Guide
For most everyday woodwork:
- Pilot holes for screws: Use a bit about half the screw diameter (e.g., 2mm for a 4mm screw). Brad point bits work great here.
- Dowel holes: Match the dowel diameter exactly (8mm dowel = 8mm brad point bit). Tight fit is what you want.
- Through-holes for bolts: Use the bolt diameter (M8 = 8mm bit for a snug fit, or 8.5mm for clearance).
- Shelf peg holes: 5mm or 6mm holes on 32mm centres (standard shelf peg spacing).
Common Mistakes
Using the wrong bit for hardwood: Twist bits wander in hard timber. Use brad point bits for clean results.
Drilling too fast: Forstner bits and large bits burn if you run them fast. Slow down.
Not clamping: Unsecured wood will spin and kick. Always clamp.
Pushing too hard: Let the bit do the work. Excessive pressure burns the hole and dulls the bit quickly.
Spade bits on hardwood: They’ll split hardwood near edges. Use brad point or Forstner bits instead.
Buying Wood Drill Bits
Build a basic set with twist bits (3–13mm), a set of brad point bits (3–12mm), and a spade bit set (4–32mm). Add Forstner bits (15–35mm) and a hole saw kit as you need them.
Quality matters: Cheap sets dull quickly. HSS (High Speed Steel) bits last longer than carbon steel, especially in hardwood. Cobalt HSS is better still, but costs more.
Amazon: Wood Drill Bit Sets (HSS) on Amazon UK
See also: What Drill Bit for Metal
See also: What Drill Bit for Masonry
See also: Drill Bit Size Chart
Watch: Video Guide
Frequently Asked Questions
Can I use a metal bit on wood?
Yes, it works, but it’s not ideal. Metal bits (HSS twist bits) are fine for wood—they’re in most universal sets. They won’t be as clean as brad point bits, but they’ll work. The issue is that they dull faster on wood because wood is abrasive.
What’s the difference between brad point and dowel bits?
Nothing—they’re the same thing. Brad point and dowel bit are interchangeable terms. The brad point design is specifically engineered for clean dowel holes, so the names stuck.
Can I use a Forstner bit in a handheld drill?
Yes, but it’s awkward. Forstner bits are designed for drill presses where they’re held steady. In a handheld drill, they’re harder to control because there’s no centre point—just the rim. For handheld drilling, brad point or hole saws are easier. If you must use a Forstner handheld, clamp the wood firmly and drill very slowly.
Why does my bit burn the wood?
Too much speed or too much pressure. Slow down, especially with large bits and hardwood. Back out the bit occasionally to clear chips. If the bit is dull, replace it—dull bits generate heat.
Do I need a backing board?
Yes, if you care about the exit side. When the bit breaks through, it can splinter the underside. Clamp a scrap board underneath—the bit exits cleanly into the scrap instead of splintering your workpiece.
What’s the best speed for drilling wood?
Start at 1500 RPM and adjust based on what you’re drilling. Large holes and hardwood = slower. Pilot holes and softwood = faster. Listen to the sound—a smooth, steady chirp is good. A grinding or burning sound means slow down.
