A drill bit is shaped for a certain material, and using the wrong one gives rough holes, burning or wandering. In short, use twist bits for metal and general work, brad-point or Forstner bits for neat wood holes, and masonry bits for brick and block. The details below show how to match the bit to the job, with a worked example, scenarios and a troubleshooting table.
Bits for wood
- Brad-point bit: has a center spur that keeps the bit from wandering and leaves clean edges.
- Spade bit: a flat paddle for quick, rough holes in framing and rough work.
- Forstner bit: cuts flat-bottomed, clean holes, useful for hinges and shallow recesses.
- Auger bit: a long screw tip that pulls itself in, made for deep holes in beams.
Bits for metal, masonry and more
- Twist bit: the standard all-rounder. High-speed steel versions handle wood, plastic and soft metals, while coated types suit tougher steel.
- Step bit: a stepped cone that drills clean holes in thin sheet metal at several diameters.
- Masonry bit: has a hardened tip, made for brick, block and concrete. Use it with the hammer setting if your drill has one and the maker’s manual allows it.
- Tile and glass bit: spear-shaped tip for brittle surfaces, used with light pressure and slow speed.
- Hole saw: cuts large round holes by removing a disc of material.
Quick match table
| Material | Bit to use | Tip |
|---|---|---|
| Softwood and hardwood | Brad-point or Forstner | Back the exit side with scrap to avoid splintering |
| Steel and aluminum | Twist bit, or step bit for sheet | Use slow speed and a drop of cutting oil |
| Brick and concrete | Masonry bit | Withdraw the bit often to clear dust |
| Ceramic tile | Tile bit | Mark with tape to stop the tip slipping |
| Plastic | Twist bit with a sharp point | Low speed so the material does not melt |
Reading sizes and shanks
Bits are sold in fractions of an inch, metric millimeters or numbered sizes. The shank is the end the chuck grips. Round shanks fit most chucks, hex shanks suit quick-change chucks and impact drivers, and SDS shanks fit rotary hammers only. Check your drill’s maximum chuck size in the manual.
Anatomy of a Twist Bit
Knowing the parts makes it easier to judge a bit. The point is the cutting tip, often ground to a set angle. The flutes are the spiral grooves that carry chips up and out of the hole. The lips are the cutting edges at the tip, and the shank is the part the chuck grips. A bit with chipped lips or rounded edges cuts slowly and produces heat, while clogged flutes need you to withdraw the bit and clear them. Specialist bits change these parts: a brad-point adds a spur, a Forstner has a rim and a flat cutter, and a masonry bit has a hard insert at the tip.
Worked Walkthrough: Choosing Bits for a Small Cabinet Job
Imagine fitting a hinge and a handle to a wooden cabinet door. The sizes depend on your hardware, so follow its instructions.
- List the holes. A shallow round recess for the hinge cup, small pilot holes for screws, and a through-hole for the handle bolt.
- Match the bit to each hole. A Forstner bit suits the flat-bottomed hinge recess. A small brad-point or twist bit suits the pilots. A brad-point bit suits the handle bolt hole.
- Check the sizes on the hardware packaging, and compare each bit against the part it must fit.
- Set the depth. For the recess, use a depth stop or wrap a piece of tape around the bit as a marker. Do not drill through the face by mistake.
- Test on scrap of the same thickness before drilling the door.
- Clamp the door to a bench with pads under the jaws, on top of a backing board for the exit holes.
- Drill steadily, clearing chips as you go, and wear eye protection.
Common Scenarios
Drilling into a brick wall for a shelf
Use a masonry bit of the size the anchor requires. Check for pipes and cables first. Follow the drill’s manual on hammer mode and dust protection.
Making a hole in a metal bracket
Mark with a punch, clamp the part and use a twist bit made for metal at low speed with oil. Finish by removing sharp edges.
A large hole for a pipe or cable through a board
A hole saw or spade bit suits this. Clamp firmly, begin slowly and withdraw to clear chips. Large bits grab, so hold the tool firmly and follow the manual.
Drilling tile
Use a tile bit, apply tape to hold the tip, and drill with light pressure at low speed. Stop when you reach the backing and switch to a bit for the wall material.
Quick Troubleshooting
| Symptom | Likely cause | What to try |
|---|---|---|
| Smoke or burning smell | Dull bit, high speed or clogged flutes | Slow down, withdraw to clear chips, replace the bit |
| Bit wanders as the hole begins | Smooth surface or no mark | Make a dimple or use a brad-point bit |
| Splintered exit | No backing | Clamp scrap behind the work |
| Bit will not cut masonry | Wrong bit or worn tip | Use a masonry bit, check hammer mode as the manual allows |
| Bit slips in the chuck | Not tight or oily shank | Clean, refit and tighten as the manual says |
Mistakes to Avoid
- Using wood bits on metal. The cutting edges are not made for it and dull at once.
- Applying too much pressure. The bit heats up, and the hole gets rough. Let the bit cut.
- Forgetting the exit side. Breakout splinters wood and burrs metal.
- Leaving chips in the hole. They jam the bit and add heat.
- Skipping eye protection. Chips, dust and fragments fly in all directions.
Care and Upkeep Over Time
Keep bits clean and dry in an index case. Remove resin from wood bits with a suitable cleaner and wipe metal swarf from twist bits. Check cutting edges for chips and rounding, and sharpen or replace as needed. Store masonry bits away from other bits so their hard tips do not damage them, and keep spares of the sizes you use often.
FAQ
Can I use one bit type for everything?
A good twist bit set gets you far, but it will not drill clean, wide holes in wood or any hole in masonry. Match the bit to the material.
Why does my bit smoke or burn?
Dull edges, too much speed or not clearing waste are common causes. Slow down, clear chips and replace a worn bit.
What does the coating on some bits do?
Coatings are meant to reduce friction or wear on certain materials. The maker’s description tells you what the coating suits, and a coated bit still wears with use.
Can I drill metal with a masonry bit?
That is not what it is made for. Use a bit designed for metal.
How do I know when a bit is worn?
If it needs more pressure, makes more heat, or leaves a rough hole, inspect the tip. Replace or sharpen it if the edges are rounded or chipped.
The Short Version
The material decides the bit. Wood likes brad-point or Forstner, metal likes twist or step bits, and masonry needs a hardened masonry bit. Check the shank, clamp small work firmly and wear eye protection every time. Keep bits clean and dry between jobs.