8 Best Drill Bits for Hardened Metal for 2026

Hardened steel, cast iron, and stainless stock can punish a weak bit fast, so your choice matters before the drill even starts. The right set gives you steadier starts, cleaner holes, and less wandering on the surface, which helps in a garage, a workshop, or a busy jobsite. You also want a shape and size range that matches the work you actually do, not a drawer full of extras you never touch.

The picks below focus on cobalt steel sets, jobber-length bits, and one long-reach option for deeper access. You’ll see where a full index set makes sense, where a small pack is easier to live with, and where a single specialty bit earns its place. The lineup keeps the comparison practical, not flashy.

Quick Look At Our Shortlist

PickWhy We Picked ItBest ForAction
IRWIN Drill Bit Set, M35 Cobalt Alloy Steel Steel, 29-Piece
Editor's Choice

IRWIN Drill Bit Set, M35 Cobalt Alloy Steel Steel, 29-Piece

Wide size spread
General metal work
Narwhal 1/2 Inch Cobalt Drill Bits (3 Pack - Industrial Grade M35 Cobalt) 6' Length & 135 Degree Split Point for Drillin
Performance Leader

Narwhal 1/2 Inch Cobalt Drill Bits 3 Pack

Large-hole drilling
Heavy metal stock
(15PCS) 1/4' Cobalt Drill Bit, HSS M35 Metal Drill Bits for Steel, Stainless Steel, Cast Iron, Hard Plastic and Wood
Value Pick

(15PCS) 1/4″ Cobalt Drill Bit, HSS M35 Metal Drill Bits

Repeat 1/4-inch work
Small-shop basics
M35 Cobalt Drill Bit Set 20PCS(1/16'-1/2') High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal with Index St
Balanced Choice

M35 Cobalt Drill Bit Set 20PCS 1/16″-1/2″

Organized range
Mixed-size jobs
LU&MN M35 Jobber Drill Bits, 1/4', 10 Pcs | M35 Cobalt HSS, Ultra Hardness & Heat-Resistant, 135° Split Point, Straight
Everyday Favorite

LU&MN M35 Jobber Drill Bits 1/4″, 10 Pcs

Simple 10-pack
Quick replacement
KENDO M35 Cobalt Drill Bit Set for Metal 13PCS
Compact Choice

KENDO M35 Cobalt Drill Bit Set for Metal 13PCS

Small, useful spread
Light kit storage
Greycore Tools 1/2 Inch x 12 Inch Cobalt Aircraft Extension Bit
Design Standout

Greycore Tools 1/2 Inch x 12 Inch Cobalt Aircraft Extension Bit

Deep reach drilling
Hard-to-access spots
29-Piece Cobalt Drill Bit Set Heavy-Duty Drill Bits
Heavy Duty Pick

29-Piece Cobalt Drill Bit Set Heavy-Duty Drill Bits

Workshop-ready spread
Frequent metal drilling

More Details On Our Top Picks

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IRWIN Drill Bit Set, M35 Cobalt Alloy Steel Steel, 29-Piece

IRWIN Drill Bit Set, M35 Cobalt Alloy Steel Steel, 29-Piece
Editor's Choice Check on Amazon

The broad size spread makes this set feel ready for real shop use, not just one-off repairs. You get 1/16-inch through 1/2-inch sizes in 1/64-inch steps, so you can match the hole closely instead of forcing the nearest bit and hoping for the best.

The 135-degree split point helps the tip start with less wandering, which matters on slick metal surfaces and curved stock. That said, a 29-piece kit asks for drawer space, so it suits a bench setup better than a tiny tool pouch.

Strong Points

  • Wide size coverage helps you match the hole more closely.
  • The split-point tip supports cleaner starts on hard metal.
  • Jobber length suits common drill-press and handheld jobs.
  • The cobalt alloy build fits frequent metal drilling use.

Things To Consider

  • The larger case takes more storage room than a small pack.
  • It may feel like more set than you need for simple household fixes.

Feature Snapshot

FeatureSpecificationWhy It Matters
Bit materialM35 cobalt alloy steelHelps the set suit harder metal work.
Size range1/16 inch to 1/2 inchGives you a broad spread for common hole sizes.
Size steps1/64-inch incrementsMakes it easier to land on a close fit.
Tip angle135-degree split pointSupports steadier starts with less skating.

Whose Shelf It Belongs On

You benefit most here if your work shifts between repairs, fabrication, and general garage drilling, because the range covers a lot of ground.

Where A Sibling Pick Shines

Choose the KENDO M35 Cobalt Drill Bit Set for Metal 13PCS when you want a smaller kit that’s easier to store in a compact toolbox.

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Narwhal 1/2 Inch Cobalt Drill Bits 3 Pack

Narwhal 1/2 Inch Cobalt Drill Bits (3 Pack - Industrial Grade M35 Cobalt) 6' Length & 135 Degree Split Point for Drillin
Performance Leader View Latest Price

Size is the whole story here, and that makes this Narwhal pack easy to understand. The 1/2-inch diameter suits larger holes in metal, while the 6-inch length gives more reach than shorter jobber bits, which helps in thicker stock or awkward access points.

The 135-degree split point again helps with entry on hard surfaces, so the bit has a steadier first bite. The trade-off is simple, though, because you only get three bits and they’re focused on one size rather than a broad kit.

What We Like

  • 1/2-inch sizing fits larger fastener and clearance holes.
  • Six-inch length adds useful reach in deeper work.
  • The split-point design helps keep starts controlled.
  • M35 cobalt construction suits harder metal surfaces.

Room For Improvement

  • The three-piece format leaves little flexibility for other diameters.
  • Longer bits can feel less handy in tight tool boxes.
  • Dedicated storage matters more here, since loose long bits can get damaged in a drawer.

Core Details

FeatureSpecificationWhy It Matters
Pack count3 bitsSignals a focused setup rather than a general kit.
Bit diameter1/2 inchTargets larger holes and heavier hardware work.
Bit length6 inchesHelps reach into deeper or harder-to-access spots.
Tip angle135-degree split pointSupports steadier starts on tough stock.

Who Should Grab It

You’re a strong match for this pack if your projects call for a single large diameter and a bit of extra reach.

Swap It Out When

The IRWIN Drill Bit Set, M35 Cobalt Alloy Steel Steel, 29-Piece fits better for mixed repair work where size variety matters more than reach.

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(15PCS) 1/4" Cobalt Drill Bit, HSS M35 Metal Drill Bits

(15PCS) 1/4' Cobalt Drill Bit, HSS M35 Metal Drill Bits for Steel, Stainless Steel, Cast Iron, Hard Plastic and Wood
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This RCINDUS pack stays focused on one workhorse size, 1/4 inch, which is a useful middle ground for shop fixtures, light fabrication, and replacement holes. The 15-piece count also makes it feel practical for anyone who burns through bits on repeat jobs and wants extras in reserve.

The M35 cobalt content is the important part, since the material choice is meant to handle harder metal better than plain high-speed steel, or HSS. The case helps with storage, though the narrow size range means you’re choosing depth in one diameter instead of flexibility across many sizes.

Highlights

  • Fifteen pieces give you a healthy replacement supply.
  • 1/4-inch sizing works for many common shop tasks.
  • M35 cobalt construction suits hard metal better than basic steel.
  • The storage case keeps the set easier to sort.
  • It works across metal, plastic, and wood tasks listed by the maker.

Softer Spots

  • Single-size kits are less flexible than mixed sets.
  • That many same-size bits only helps when 1/4 inch is the hole you need.

Details At A Glance

FeatureSpecificationWhy It Matters
Pack count15 bitsGives you backups for repeated use.
Diameter1/4 inch, 6.35 mmMatches a very common workshop hole size.
MaterialM35 HSS with 5% cobaltHelps the bit better suit harder materials.

Best Suited To

You fit this set best if you often drill 1/4-inch holes in a small shop, on repairs, or during assembly work.

A Better Fit Elsewhere

The Sabre Tools 29-Piece Cobalt Drill Bit Set makes more sense when you need a broader size range for mixed metal jobs.

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M35 Cobalt Drill Bit Set 20PCS 1/16"-1/2"

M35 Cobalt Drill Bit Set 20PCS(1/16'-1/2') High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal with Index St
Balanced Choice View on Amazon

This WildBossy set hits a very workable middle point between a massive kit and a tiny specialty pack. The 1/16-inch to 1/2-inch spread gives you room for everyday fabrication, hardware work, and repair tasks, while the index case keeps the pieces organized instead of scattered in a drawer.

Jobber length means a standard-purpose bit body, which is usually the easiest shape to live with for general drilling. The honest read is that this kind of set makes the most sense when you want coverage and order, not just raw toughness in one diameter.

Best Bits

  • The 20-piece layout covers many common hole sizes.
  • The index case makes size sorting easier.
  • Jobber length is a familiar, versatile format for hand drills.
  • M35 cobalt construction fits frequent metal drilling.

Points To Note

  • It asks for more storage room than a small pack.
  • Some jobs may need a more specialized long bit instead.
  • Cases like this work best when you keep them closed and sorted, so pieces do not mix up between jobs.

Quick Facts

FeatureSpecificationWhy It Matters
Pack count20 bitsSupports a wider mix of repair and project sizes.
Size range1/16 inch to 1/2 inchLets you match more hole diameters.
Length styleJobber lengthFits common handheld drilling use.
StorageIndex storage caseKeeps the set easier to organize and carry.

Built With In Mind

You should look here if you want a mid-sized kit for regular metal work in a home garage or small shop.

Reach For A Different Pick When

The Narwhal 1/2 Inch Cobalt Drill Bits 3 Pack is the cleaner choice when your work centers on larger holes and deeper access.

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LU&MN M35 Jobber Drill Bits 1/4", 10 Pcs

LU&MN M35 Jobber Drill Bits, 1/4', 10 Pcs | M35 Cobalt HSS, Ultra Hardness & Heat-Resistant, 135° Split Point, Straight
Everyday Favorite Check on Amazon

The LU&MN set is a straightforward answer for anyone who keeps reaching for 1/4-inch bits. Straight shanks are easy to clamp in common drills, and the 135-degree split point helps the tip settle in with less slipping on metal.

Because it’s a 10-pack, you’re getting a practical replacement supply without the storage burden of a larger index case. That said, the single diameter keeps it specialized, so it feels more like a dependable small bundle than a full solution for mixed-size work.

Upsides

  • The 10-piece count works well for repeat use.
  • 1/4-inch sizing covers a common drilling need.
  • Straight shanks fit standard drill chucks cleanly.
  • The split point helps with steadier starts.

Minor Gripes

  • The single size limits how far the set can carry you.
  • You may want labeled storage so the same-size bits stay easy to sort.

Technical Sheet

FeatureSpecificationWhy It Matters
Pack count10 bitsProvides extras for frequent 1/4-inch drilling.
MaterialM35 cobalt HSSSupports harder metal work better than basic steel.
Tip angle135-degree split pointHelps the bit start with less walking.
Shank styleStraight shankFits common chuck setups.

Right Fit For

You suit this pack best when your day-to-day drilling leans heavily on one useful diameter and you want extras close at hand.

Look Elsewhere When

The IRWIN Drill Bit Set, M35 Cobalt Alloy Steel Steel, 29-Piece works better for broader metalwork where many sizes matter.

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6 / 8

KENDO M35 Cobalt Drill Bit Set for Metal 13PCS

KENDO M35 Cobalt Drill Bit Set for Metal 13PCS
Compact Choice View Latest Price

KENDO keeps the range tight, and that helps this set stay easy to store without feeling bare. The 1/16-inch to 1/4-inch spread covers a lot of small- to medium-duty metal work, plus the 135-degree tip gives a more controlled start on slick surfaces.

It’s a good match for compact tool bags and home workspaces where you want enough range to be useful but not a crowded case. The trade-off shows up on bigger projects, because you won’t have the large diameters that the IRWIN or Sabre Tools sets provide.

Reasons To Buy

  • The smaller footprint makes storage simple.
  • The size range covers several everyday drill needs.
  • 135-degree tip geometry helps with steadier starts.
  • Jobber length is easy to use with standard drills.

Areas To Watch

  • The set stops at 1/4 inch, so larger hole work needs another option.
  • Smaller kits can disappear in a crowded toolbox unless you keep the case together.

Feature Rundown

FeatureSpecificationWhy It Matters
Pack count13 bitsOffers enough pieces for compact general use.
Size range1/16 inch to 1/4 inchMatches smaller drilling needs well.
Tip angle135-degree tipSupports cleaner starts on hard surfaces.
Bit styleTwist jobber lengthKeeps the shape familiar and versatile.

The Right Fit

You’re in the sweet spot here if you want a compact cobalt set for smaller metal jobs and easier storage.

Not Your Match When

The Sabre Tools 29-Piece Cobalt Drill Bit Set makes more sense for larger workshop coverage and broader size variety.

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7 / 8

Greycore Tools 1/2 Inch x 12 Inch Cobalt Aircraft Extension Bit

Greycore Tools 1/2 Inch x 12 Inch Cobalt Aircraft Extension Bit
Design Standout Check Latest Price

This Greycore bit fills a very specific need, and that’s its strength. The 12-inch length gives you reach that normal jobber bits simply do not, which helps when you’re drilling through deep material, into recessed areas, or around awkward framing.

The industrial titanium coating is part of the package too, and it suggests added surface durability for repeated use. The catch is that long bits ask for more control, so the fit is best for people who already know how to keep a drill steady on a long reach.

Bright Spots

  • The 12-inch reach is useful in deep or awkward spaces.
  • 1/2-inch sizing handles larger-diameter work.
  • Cobalt construction suits harder materials.
  • The coated finish adds a tougher outer surface.

Small Caveats

  • Long bits can feel less forgiving in tight spaces.
  • The single-bit format only solves one kind of job.
  • Storage matters here, since a long bit can bend or get nicked if it rattles around loose.

At A Glance

FeatureSpecificationWhy It Matters
Size1/2 inchTargets larger holes.
Length12 inchesGives extra reach for deep work.
MaterialM35 cobaltHelps with harder material drilling.
CoatingIndustrial titanium coatingAdds a more durable outer finish.
Bit typeLong length drill bitMatches jobs that need extended access.

Who Will Love This

You fit this bit best if your work often reaches into deep assemblies, machinery, or other hard-to-access spots.

Where Shoppers Go Wrong

The KENDO M35 Cobalt Drill Bit Set for Metal 13PCS is the safer match for general-purpose use, because it covers more sizes in a compact package.

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29-Piece Cobalt Drill Bit Set Heavy-Duty Drill Bits

29-Piece Cobalt Drill Bit Set Heavy-Duty Drill Bits
Heavy Duty Pick View on Amazon

Sabre Tools gives you the kind of broad set that feels ready for frequent use in a workshop or garage. The 29-piece count helps cover a wide spread of drill sizes, so you are less likely to reach for another box halfway through a job.

That larger count is useful, but it also means more storage and more sorting to keep track of the pieces. Compared with the smaller LU&MN and KENDO packs, this one suits people who value range first and tidy compactness second.

Positives

  • The 29-piece count gives you broad size coverage.
  • It suits repeated drilling across steel and cast iron work.
  • A larger set reduces the need to hunt for another pack.
  • The mix works well in a shared shop or busy garage.

Worth Noting

  • The larger set needs more organized storage.
  • It can feel like too much for someone who only drills the same few sizes.

Core Details

FeatureSpecificationWhy It Matters
Pack count29 piecesGives broad coverage for varied tasks.
Bit familyCobalt drill bit setHelps the set suit harder metal work.
Use focusSteel, hard metal, cast ironShows the set’s main drilling targets.

Made For

You suit this set best if you want a workshop staple that can cover a lot of different metal-drilling jobs.

Another Choice May Suit

The LU&MN M35 Jobber Drill Bits 1/4", 10 Pcs fit better for shoppers who only need a small, repeat-use 1/4-inch pack.

View Latest Price

How To Choose The Right Drill Bits For Hardened Metal

Material And Tip Shape Matter First

M35 cobalt is a smart place to start because cobalt content helps the bit suit harder stock better than basic high-speed steel alone. You also want a split point or sharply angled tip, since that helps the bit start with less skating on smooth metal.

The trade-off is simple, cobalt bits usually cost more than plain steel bits, and the harder material can be less forgiving if you force the cut. A slower pace and steady pressure matter more than brute force here.

Match The Bit Length To The Job

Jobber length is the standard middle ground, useful for most handheld drilling and many bench setups. Long bits, such as the 12-inch Greycore option, make sense for deep reach, recessed areas, or awkward angles.

Longer reach can feel a bit like a fishing rod on a windy day, because control matters more as the bit grows. For most garage work, standard length is easier to handle and store.

Choose Size Range Based On Daily Use

A full set helps when your projects change often, especially in fabrication, repair, or general maintenance. Single-size packs fit better when you keep drilling the same diameter over and over.

The best match depends on how much variety sits on your bench. Mixed kits save time, while focused packs keep your drawer clean and your spending narrow.

Think About Storage And Wear

An index case helps keep sizes in order, which matters more as the piece count grows. Loose bits can get chipped, mixed up, or buried under other tools, so storage is part of the purchase, not an afterthought.

Shoppers who drill often should also think about replacement supply. A 10-pack or 15-pack makes sense for repeat work, while a 29-piece set reduces the need to piece together a kit later.

What To Weigh Before You Choose

Mistakes Worth Dodging

The most common miss is treating all metal bits the same. Hardened steel, stainless, and cast iron ask for more than a basic bit shape, so the material and tip design need attention first.

Another easy mistake is buying too much size overlap. A big set looks useful, but a smaller, focused pack often serves you better when your work stays narrow and repetitive.

Where The Extra Money Goes

Higher-tier sets usually spend more on cobalt content, cleaner tip geometry, and better organization. That adds up when you drill hard stock often, because steadier starts and better wear resistance matter more than extra frills.

For occasional home repairs, a modest kit can be enough. For frequent garage or fabrication use, the upgrade is easier to justify because the set carries more of the load and usually stays easier to manage.

Frequently Asked Questions

What makes cobalt bits better for hardened metal?

Cobalt bits are built with material that suits harder stock better than plain steel bits. They’re a practical match for metal that can punish a softer bit quickly.

Do you need a split point on every metal bit?

Split points help the tip start with less wandering, which is useful on smooth metal surfaces. That said, they’re most helpful when you care about cleaner placement from the first touch.

Is jobber length enough for most shop work?

Jobber length covers most routine drilling jobs in a garage or workshop. Deeper work, recessed holes, or awkward access points are where longer bits start to make more sense.

Should you choose a full set or a single-size pack?

A full set makes sense for mixed jobs and changing hole sizes. A single-size pack works better when you keep returning to one common diameter, such as 1/4 inch or 1/2 inch.

How should you store metal drill bits?

An index case or organized holder helps keep sizes sorted and edges protected. Loose storage usually leads to more mess and more wear on the bits.

Closing Thoughts

The right drill bit set depends on how often you drill hard metal and how much size variety your projects demand. Broad kits like the IRWIN and Sabre Tools sets suit general workshop use, while focused packs from LU&MN, Narwhal, and KENDO fit tighter needs. For deep access, the Greycore long bit stands apart, and the RCINDUS pack is a smart middle path for repeated 1/4-inch work. Match the bit to the task, keep the set organized, and the job feels far less stubborn.

Tool Staff
Tool Staff

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