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Beginner DIY · Tool Use

How to Choose the Right Drill Bit

Most tools have a 'right way' that takes 30 seconds to learn and saves you from countless mistakes. The DIY problem isn't the tool, it's the assumption that any tool can be used by feel.

Beginner 5 min to learn the categories

Drill bits are matched to materials. Use the wrong bit and you'll burn out the bit, ruin the workpiece, or take forever to make a hole. The right bit cuts cleanly, lasts for many holes, and matches the work — wood, metal, masonry, tile, and glass each have specific bit types.

This guide explains which bit type to use for each material and what to look for in quality. Five common bit categories cover most renovation jobs.

Before you start

Three things to settle:

1. Material drives bit choice. Wood: twist bits, brad-point, spade, hole saws. Metal: HSS twist bits or cobalt for hard metals. Masonry: carbide-tipped masonry bits. Tile: diamond-tipped or carbide tile bits. Glass: spear-point glass bits. Each is designed for the specific material's behaviour.

2. HSS vs carbide vs diamond. High-speed steel (HSS): general purpose, wood and most metals. Cobalt: harder than HSS, for stainless and tough metals. Carbide: very hard, for masonry and abrasive materials. Diamond: hardest, for tile, glass, ceramics.

3. Pilot holes are smaller than the screw. Pre-drill bits should be smaller than the screw shank — typically 60-70% of the screw's outside diameter. Hardwood needs pilot, softwood often doesn't. The drill bit set should include sizes matching the screws you use.

What you'll need

Tools

  • Drill (cordless or corded)
  • Bit storage (case)

Materials

  • Twist bit set (1/16 to 1/2 inch, HSS) — most common, wood and metal
  • Brad-point bit set — clean entry holes in wood
  • Spade bits (3/4 to 1.5 inch) — fast wood holes
  • Hole saw set — large diameter wood holes
  • Masonry bit set (1/4 to 1/2 inch carbide) — concrete, brick
  • Tile bit (1/4 inch diamond or carbide) — ceramic and porcelain
  • Cutting fluid or wax — metal drilling lubricant

Use a smaller pilot bit before the final size

When drilling holes larger than 1/4 inch in wood or metal, pre-drill a smaller pilot hole first (1/8 inch typical). The pilot guides the larger bit and reduces tear-out.

Glass and tile: always pre-drill with smaller diamond bit; never start at full diameter.

Step-by-step instructions

Identify the material

Wood (hardwood vs softwood, finished vs raw).

Metal (steel, aluminum, stainless).

Masonry (concrete, brick, mortar).

Tile/ceramic.

Glass.

Each requires a different bit category.

Pick bit type for the material

Wood, small hole: twist bit.

Wood, clean entry holes (cabinetry): brad-point bit.

Wood, fast large holes (1/2 to 1.5 inch): spade bit.

Wood, large diameter (over 1.5 inch): hole saw.

Metal: HSS twist bit, cobalt for stainless.

Concrete/brick/mortar: carbide masonry bit (with hammer mode if drilling concrete).

Tile: diamond or carbide tile bit.

Glass: spear-point glass bit.

Pick size

For pilot holes: 60-70% of screw's outside diameter.

For through-holes (decorative or pass-through): match the bolt or wire diameter.

For mounting hardware: match the manufacturer's specified pilot size.

Inspect the bit before use

Sharp cutting edges (nicked or rounded edges = dull = burn marks).

Straight shank (bent bits wobble in chuck).

No visible damage.

Insert into chuck and tighten

Open chuck wide enough.

Insert bit shank fully (most modern self-tightening 3-jaw chucks).

Tighten by hand or with chuck key (older drills).

Verify bit doesn't wobble when running.

Drilling wood: brad-point vs twist

Brad-point: starts cleanly with no walking; clean entry holes for cabinetry and visible work.

Twist: works fine but can walk and chip on entry. Mark with awl first to prevent walking.

Variable speed: medium speed for hardwoods, faster for softwoods.

Drilling metal: lubricant + slow speed

Apply cutting oil or wax to the bit and workpiece — reduces heat, extends bit life.

Slow speed for hard metals; medium for aluminum.

Steady pressure; let the bit do the work.

If smoke appears: too fast, too dull, or insufficient lubricant.

Drilling masonry: hammer mode + slow

Use a drill with hammer mode (or rotary hammer for thick concrete).

Carbide masonry bit.

Slow speed; firm pressure.

Periodically pull bit out to clear dust from the hole.

Drilling tile: low speed, water cooling

Diamond bit or carbide tile bit.

t or carbide tile bit.

Very low speed — high speed cracks tile.

Cool with water (drip or sponge) — heat cracks tile.

Pre-drill with smaller bit; gradually increase to final size.

Maintain bits for longevity

Clean wood resin off bits with mineral spirits.

Keep bits dry and stored in case.

Replace dull bits — sharpening twist bits is possible but tedious.

Carbide and diamond bits last 10× longer than HSS for their materials.

Common mistakes that cost you

Frequently asked questions

Do I need a separate set for metal?

HSS twist bits work for both wood and most metals — one set covers a lot.

Cobalt bits needed for stainless steel and hardened steel.

Avoid carbon-steel bits (cheap, dull fast).

How do I drill a hole through tile without cracking it?

Diamond bit or carbide tile bit.

Mark the hole; place painter's tape over the spot to prevent the bit from skating.

Very low speed, firm pressure, water cooling.

Pre-drill with smaller bit, increase gradually.

Can I sharpen drill bits?

Yes — bench grinder with a drill bit sharpening jig.

Many DIYers don't bother; new bits are cheap.

Carbide and diamond bits: don't try to sharpen at home.

When to call us instead

Our crews carry full bit sets for every material on every job. Right bit, right size, every time.

Book a free 60-minute site visit →

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