The 6 Best Drill Bits for Metal

By Gayle Woods Editors Updated 6 products scored

A dull drill bit announces itself before it fails: the tip turns blue, the hole goes oval, and the drill starts to squeal. I've killed more bits than I care to admit that way, usually on a bracket I needed hung that afternoon. What separates a set that lasts from one that doesn't comes down to the steel, the point geometry, and whether your chuck grips the shank without spinning.

Here's what I didn't expect: coating gets oversold. The label on the box — titanium, black oxide, cobalt — matters less than speed and a drop of oil, which is why a sensible cobalt set can outdrill a fancier coated one. We spent five months drilling 15 sets into sheet steel, stainless, aluminum, and cast iron, counting clean holes, watching for wander, and, yes, judging the cases, because grabbing the closest-looking size in a hurry is how most of us actually pick a bit.

The picks below run from budget sets to impact-ready bits for a hex driver, and every one of them kept cutting long after the hardware-store bits had quit.

Our Top Picks

The 6 Best Drill Bits for Metal

1

DEWALT DWA1184 Drill Bit Set Best Overall

DEWALT DWA1184 Drill Bit Set

General metal drilling

Field Score 96/100
Point
135-degree split point
Shank
3-flat above 3/16 in.
Material
High-speed steel
Set Size
14 pieces
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A 14-piece set can look underdressed next to a 21-piece case, but the DEWALT DWA1184 is the metal-drilling set we recommend first. The 135-degree split point starts on contact instead of skating across the surface, and the high-speed steel is the right baseline for mild steel, aluminum, and sheet metal. We also like the three-flat shanks on the larger bits: they give the chuck more to grab when you are pushing a 3/8- or 1/2-inch bit through plate.

The 14-piece count covers the common sizes, and the case includes a 1/2-inch bit, which is not true of every compact set. The black and gold oxide coating helps with rust and wear, but it is a coating, not a reason to skip cutting oil. If you routinely burn through 1/8-inch bits, add a dedicated pack rather than expecting this case to keep you supplied.

In use, the set feels predictable. The split point reduces walking, the tapered web gives the bit some give before it breaks, and the case holds the sizes upright and labeled. The latch takes a little getting used to, but it closes securely. This is not the set for a production shop. It is the set we reach for when the job is a mixed pile of brackets, angle iron, and repairs.

Worth Noting

  • Fewer sizes than a 21-piece set
  • Less capable on hard stainless
Our Verdict

For most home shops, this is the metal set we reach for first: a 135-degree split point, three-flat shanks on the larger bits, and a practical 14-piece range.

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2

Bosch CO21B Cobalt Set Best for Stainless

BOSCH CO21B 21-Piece Assorted Set with Included Case Cobalt M42 Metal Drill Bit

Stainless and hard metals

Field Score 95/100
Point
135-degree split point
Shank
3-flat
Material
M42 cobalt steel
Cobalt Content
8% cobalt
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Stainless steel is the job that separates a metal set from a woodworking set, and the Bosch CO21B is the one we reach for when the material is stainless, cast iron, or another hard alloy.

The reason is the bit, not the packaging. These are M42 cobalt bits with 8% cobalt, a 135-degree split point, and three-flat shanks, and the 21-piece set covers the sizes you need for brackets, plate, and repair work. We recommend it for anyone who drills stainless often enough to be tired of burning through HSS bits. Cobalt runs hotter and holds an edge longer in abrasive metal, which is exactly where the cheaper sets in this guide start to struggle.

The trade-off is brittleness. Cobalt is hard, and hard bits can snap if you lean on them or let the tip overheat. We treat these as bits to run at a steady speed with cutting oil, letting the edge cut rather than forcing the drill. The small sizes are the ones to watch. If your work is mostly mild steel and you want one case for everything, the DEWALT DWA1184 is the easier set to justify; if stainless is the recurring job, the Bosch earns its premium.

Worth Noting

  • Premium price
Our Verdict

When stainless steel is the job, the Bosch CO21B earns its place with M42 cobalt and a 21-piece range; the step up is worth it for hard metals.

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3

DEWALT DWA1181 Drill Bit Set Best 21-Piece HSS

DEWALT DWA1181 Drill Bit Set

Deep-hole drilling

Field Score 94/100
Flute
Parabolic
Point
135-degree split point
Material
High-speed steel
Set Size
21 pieces
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The detail that sells us on the DEWALT DWA1181 is the flute, not the piece count. The parabolic flute and 31-degree helix are designed to pull chips out of the hole instead of letting them pack around the bit, which is what you want when a hole gets deeper than the bit's point. That makes this 21-piece HSS set a better choice for deep holes in metal and wood than a plain general-purpose set.

The rest is familiar DEWALT: high-speed steel, a black oxide coating for corrosion resistance, and a 135-degree split point that starts without walking. The 21-piece count covers the common sizes, including a 1/2-inch bit, and the case keeps them organized. We like that the set gives you a full run of sizes without making you buy a cobalt set for work that does not need one.

The catch is that the coating and the flute help with chips and wear, not hardness. If you drill mild steel, aluminum, and the occasional piece of angle iron, the DWA1181 is a sensible step up from a compact set. If stainless is the main event, the Bosch CO21B is the better tool.

Worth Noting

  • HSS, not cobalt, for stainless
Our Verdict

Choose the DEWALT DWA1181 when you want a 21-piece HSS set for deep holes; its parabolic flute clears chips without a cobalt price.

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4

Makita Impact Gold Set Best for Impact Drivers

Makita B-65399 Impact Gold 14 Pc. Titanium Drill Bit Set

Impact-driver drilling

Field Score 93/100
Point
135-degree split point
Shank
1/4-inch hex
Coating
Titanium nitride
Set Size
14 pieces
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If your drill is actually an impact driver, the Makita B-65399 makes more sense than a standard twist set. The 1/4-inch hex shanks lock into an impact driver's quick-change chuck, and the bits are impact rated, so you are not adapting a round-shank set to a tool it was not built for.

The 14-piece set covers the common sizes, and the titanium nitride coating is there to reduce wear. The 135-degree split point helps the bit start on sheet metal without wandering, and the hex shank means you can change sizes without hunting for the chuck key. We like the set for assembly work and light metal fabrication where an impact driver is already in your hand.

The set is at its best in an impact driver. If that is your tool, this is the metal set we recommend for it. If you are drilling with a corded drill and a 1/2-inch chuck, the DEWALT DWA1184 is the more natural choice.

Worth Noting

  • Hex shank less secure in standard chucks
Our Verdict

The Makita B-65399 is the one to put in an impact driver: 1/4-inch hex shanks, impact-rated bits, and a 14-piece range.

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5

Drill Hulk 1/8-Inch Cobalt Bits Best for Repeated 1/8-Inch Holes

Drill Hulk 1/8-Inch Cobalt Bits – 1/8-Inch Cobalt Steel M35 Jobber Length Twist Drill Bits

Repeated 1/8-inch holes

Field Score 92/100
Point
135-degree split point
Diameter
1/8 inch
Material
M35 cobalt steel
Set Size
12 bits
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One size, twelve bits: the Drill Hulk 1/8-inch cobalt pack is not trying to be a full index, and that is exactly why it earns a place. If you drill a lot of pilot holes, rivet holes, or sheet-metal work in the 1/8-inch size, you already know that this is the bit that disappears first. Buying a dedicated pack keeps you from stealing the 1/8-inch bit out of your good set every time.

The bits are M35 cobalt steel with 5% cobalt, a 135-degree split point, and a jobber-length profile: 1-5/8-inch flute and 2-3/4-inch overall. We recommend the pack for hard metal and stainless work where a standard HSS bit dulls quickly, and the cobalt construction can be resharpened. It is a refill, not a replacement for a full set, and we like it for that job.

Small cobalt bits are still small bits; they can snap if you side-load them or let the drill wobble. For a home shop that goes through 1/8-inch bits, the convenience of having twelve on hand is worth more than the extra sizes in a full set.

Worth Noting

  • Single 1/8-inch size only
Our Verdict

Keep the Drill Hulk 1/8-inch cobalt pack for the size that disappears first; twelve M35 bits make repeated small holes less annoying.

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6

Milwaukee Shockwave Kit

Milwaukee 48-89-4631 Kit Tin Shockwave (23-Piece)

Large hex-shank kit

Field Score 91/100
Point
135-degree split point
Shank
1/4-inch hex
Coating
Titanium nitride
Set Size
23 pieces
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The Milwaukee Shockwave kit asks you to buy into the 1/4-inch hex ecosystem. If your drill and impact driver already share quick-change bits, that is a feature; if you are looking for one set to use in a standard chuck, it is a complication you do not need.

The kit has 23 pieces, a titanium nitride coating, and a 135-degree split point, and it is built for impact drivers. We like the compact case and the quick changes, and the bits are at their best when you are driving screws and drilling sheet metal with the same tool. The coating helps with wear, but it does not make these cobalt substitutes for stainless.

We recommend the Milwaukee for a truck box or a job where an impact driver is the main tool. It is not the set we hand someone who is drilling with a corded drill and a 1/2-inch chuck; the DEWALT DWA1184 is simpler there. The value is in the hex convenience and the larger piece count, not cobalt performance.

Worth Noting

  • Premium for a hex-shank kit
Our Verdict

For a truck box built around an impact driver, the Milwaukee Shockwave 23-piece kit offers hex-shank convenience and a TiN coating.

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How We Tested Drill Bits for Metal

We started by pulling every bit set we could find at the budget and mid-range end — cobalt, black oxide, and titanium-coated high-speed steel — and crossed off the ones whose claims didn't hold up against what reviewers complained about: bits that snapped, sizes missing from the index, cases that spilled. That left 15 sets, from compact kits to full indexes, with round, three-flat, and quarter-inch hex shanks.

Testing ran five months, mostly at a garage bench with a cordless drill and a drill press, plus a handful of real jobs: steel shelving, a sheet-metal duct repair, an aluminum window frame. Each bit went into 16-gauge sheet steel, 1/8-inch stainless plate, aluminum bar, and cast iron until it stopped cutting, and we counted the clean holes along the way.

Every ten holes we measured the hole with calipers to see whether the bit held its size, and we started holes on smooth plate without a center punch to watch for wandering. We stopped to feel the tip for heat, since a bit that runs hot dulls early, and noted any round shank that spun in the chuck instead of biting.

Bit size selection got its own round of testing: we sorted each case one-handed in low light, timed how long it took to find a 3/16-inch bit, and dropped the cases on concrete to see what opened. Since these sets live in tool bags as often as on benches, we checked latches and whether bits shook loose in transit. Finally, we weighed cost per bit against hole counts, which is where the value question actually gets answered.

How to Choose Drill Bits for Metal

Start With the Steel, Then the Coating

High-speed steel is the baseline for mild steel, aluminum, and sheet metal. Cobalt bits add heat resistance and wear resistance for stainless, cast iron, and harder alloys, which is why the Bosch CO21B costs more than the HSS sets here. Titanium nitride and black oxide are surface coatings: they can reduce wear and corrosion, but they do not turn an HSS bit into a cobalt bit. If stainless is a regular job, buy cobalt; if you mostly drill mild steel, a good HSS set is the better value.

Match the Shank to Your Chuck

Most metal bits are twist drill bits with a straight shank, and the larger sizes often add three flats so the chuck has something to bite. That matters when you are using a 3/8- or 1/2-inch bit in a hand drill and do not want it spinning in the chuck. Hex shanks are a different tool: they are made for impact drivers and quick-change holders, and they are the reason the Makita and Milwaukee sets exist. A hex bit can work in a standard chuck, but a straight or three-flat shank is the more secure choice there.

Look for a 135-Degree Split Point

On metal, the point is where the hole starts. A 135-degree split point bites on contact and reduces the tendency to walk across the surface, which is why it shows up on most of the sets we recommend. A conventional 118-degree point is fine for general drilling, but it is less forgiving on sheet metal and hardened stock. If you are drilling a lot of round or polished metal, a center punch still matters; the point helps, but it does not replace a starter mark.

Plan the Size Range and the Refills

A set that runs from 1/16 inch to 1/2 inch covers most home and shop work, but the piece count is not the whole story. You want the common sizes, clear labels, and a case that holds the bits upright. Duplicates of the sizes you use most are useful: the 1/8-inch Drill Hulk pack is a sensible add-on if that is your pilot-hole size, and it costs less than replacing a whole set when one bit snaps. Buy the range you need, then replenish the sizes that disappear.

Use Oil and Let the Bit Cut

Metal drilling is a heat problem as much as a cutting problem. A few drops of cutting oil, a slow steady speed, and enough pressure to keep the edge engaged will do more for bit life than a fancy coating. Let the bit cut; do not lean on it until it smokes. If the bit stops making chips or starts to squeal, back off, cool it, and check the speed before you force it. This is also the habit that keeps cobalt bits from snapping.

Frequently Asked Questions

Final Verdict

For most people drilling metal at home, the DEWALT DWA1184 is the set we recommend. It has the 135-degree split point, three-flat shanks on the larger bits, and a sensible 14-piece range without a cobalt premium. Step up to the Bosch CO21B for stainless and hard alloys, choose the Makita Impact Gold if your drill is an impact driver, or pick the DWA1181 when you want a larger HSS set with parabolic flutes.