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13 Best Drill Bits for Stainless Steel in 2026: Genuine Cobalt That Won't Quit

Find the best drill bits for stainless steel that cut clean holes without burning up—for DIYers and metalworkers drilling hard metal with confidence.

Many drill bits sold as 'stainless steel capable' turn out to be titanium-coated high-speed steel that dulls after a single hole. The culprit isn't poor workmanship—it's the intense heat and hardness of stainless, which demands a different bit material altogether.

This guide separates the marketing claims from the metal. You'll know exactly which bits are built for repeated stainless work and which are best saved for wood and plastic. The simple adjustments—low speed, steady pressure, and cutting oil—can double the life of any bit, but matching the bit to the job is what keeps a project moving forward.

#01

Best Overall

Bosch CO14 Cobalt Set

95 /100
Kirk Score Outstanding
Pieces
14
Material
M42 Cobalt Steel
Shank Type
3-Flat
Size Range
1/16 in. to 1/2 in.
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Pros

  • Bites into stainless steel, cast aluminum, and mild steel without walking or chattering.
  • Build quality and sizing consistency outclass many similarly-priced cobalt sets.
  • Edge retention stays sharp after repeated holes, reducing replacement frequency.

Cons

  • Cobalt's extreme hardness makes bits brittle; flexing, dropping, or off-angle hand drilling can snap smaller diameters.

M42-grade cobalt steel and a split-point tip allow these bits to start on contact in hardened stainless, cast iron, and alloy steel without a center punch. The 3-flat shank locks securely into the chuck, preventing slip on larger sizes. Cutting edges hold up through repeated holes in material that dull standard TiN bits within seconds. Slow speeds and cutting oil produce clean, burr-free results.

This set targets metalworkers and fabricators who drill stainless steel regularly and are comfortable with the discipline of low RPMs, cutting oil, and a drill press or very stable hand. It's not for wood-only shops or those unwilling to adapt technique — lateral force or a drop can snap smaller bits. For that tradeoff, you get a durable, imperial-sizes kit in a well-organized case.

💡 Tip: Always use cutting oil and a drill press when possible; cobalt's heat resistance works best at low RPMs to avoid brittle failure.

Bottom line: If stainless steel is a regular drilling target and you can give it a drill press or rock-steady hand with cutting oil, the CO14 delivers professional-grade results that TiN sets cannot match.

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#02

Best DEWALT Cobalt Option

DEWALT DWA1240 Cobalt Set

92 /100
Kirk Score Outstanding
Pieces
14
Material
Cobalt Alloy Steel
Shank Type
Straight
Size Range
1/16 in. to 1/2 in.
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Pros

  • Cobalt alloy steel cuts thick stainless and alloy steel with minimal effort.
  • Pilot point tips start holes cleanly without a center punch, reducing walk on metal surfaces.

Cons

  • Edge retention can be shorter under sustained high-RPM stainless drilling, particularly compared to the Bosch CO14 set.

Unlike DEWALT's TiN-coated generalist bits, the DWA1240 uses genuine cobalt alloy steel to handle thick stainless and alloy steels that wear down lesser bits. The 14-piece set spans 1/16 to 1/2 inch, making it a practical upgrade for DEWALT loyalists who drill stainless regularly and want the speed of a pilot point that starts cleanly without a center punch. Edge life lags behind the top-performing Bosch CO14 under sustained high-speed use — a tradeoff for the convenience and brand familiarity.

💡 Tip: Use cutting oil and moderate RPMs on stainless to extend edge life.

Bottom line: A solid cobalt set for DEWALT users upgrading from TiN bits; the pilot point saves setup time, though edge life may not match the Bosch CO14 in continuous production drilling.

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#03

Best Metric M42 Cobalt Set

STROTON M42 Metric Set

89 /100
Kirk Score Excellent
Pieces
19
Material
M42 Cobalt (8% Co)
Shank Type
Straight
Size Range
1 mm to 10 mm
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Pros

  • M42 cobalt at 68-70 HRC stays sharp through hardened stainless and tough alloys.
  • Metric 0.5 mm increments cover precise sizing for European and Asian machinery.
  • 135° split point design starts fast and minimizes walking in metal.

Cons

  • Sub-2 mm bits are extremely fragile and may snap under off-center hand drilling; treat them as consumables.

The 19-piece STROTON set uses M42 8% cobalt to achieve a 68-70 HRC hardness that slices through hardened stainless, tool steel, and titanium alloys. The 135° split point bites immediately and resists walking, while metric sizing from 1 mm to 10 mm in 0.5 mm steps covers the precision needs of European and Asian machinery.

Mechanics and machinists working on metric fasteners and diesel components will appreciate the specific increments and heat tolerance. The sub-2 mm bits, however, are delicate — treat them as consumables and avoid off-center hand drilling to prevent snapping. This set suits users who primarily drill larger metric holes and can handle small bits with care.

💡 Tip: Reserve the sub-2 mm bits for use in a drill press or with a rigid guide — hand-held wobble can snap them.

Bottom line: Metric precision and M42 hardness make this the set for European car and machinery work, provided you treat the smallest bits with the care they demand.

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#04

Best Bulk Single-Size Value

Drill Hulk 1/4" Cobalt 12pk

92 /100
Kirk Score Outstanding
Pieces
12
Material
M35 Cobalt (5% Co)
Shank Type
3-Flat
Size Range
1/4 in. only
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Pros

  • Excellent per-bit value when you need many 1/4-inch holes
  • Cuts 304 stainless cleanly and maintains cutting edge across multiple holes
  • Less prone to snapping under typical pressure compared to generic M35 bits

Cons

  • M35 cobalt composition can struggle or walk on hardened tool steel; optimized for stainless up to mid-range hardness

This 12-pack of identical 1/4-inch M35 cobalt bits is purpose-built for repetitive stainless work. Unlike the top pick that covers a range of sizes with M42 cobalt, Drill Hulk focuses on a single diameter to slash the per-hole cost for trailer builders, automotive shops, and anyone drilling numerous 1/4-inch bolt or rivet holes. The tradeoff: you'll need a separate index for other sizes. But if your job is drilling through 304 stainless plate all day, this bulk pack keeps you in fresh bits at an unbeatable price.

Bottom line: For anyone drilling dozens of 1/4-inch holes in stainless per project, this pack offers the lowest cost-per-hole we've seen — just pair it with a cobalt set for other diameters.

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#05

Best General-Purpose Mixed-Material Set

DEWALT DW1361 TiN Set

96 /100
Kirk Score Outstanding
Pieces
21
Material
TiN Coated HSS
Shank Type
Hex (no-spin)
Size Range
1/16 in. to 1/2 in.
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Pros

  • Pilot point reduces wandering, starts cleanly without center punch.
  • Solid value for a name-brand 21-piece kit.
  • Sharp out of the box through wood, plastic, and mild steel.

Cons

  • Smaller bits can snap under heavy load, particularly on stainless steel without proper speed and lubrication.

The pilot point tip bites into material without a center punch, minimizing wandering on curved or slick surfaces. Across 21 sizes from 1/16 to 1/2 inch, the hex shanks grip well in chucks, and the TiN coating reduces friction in wood, plastic, and mild steel. When used on stainless steel, the coating wears faster and the bits dull more quickly than genuine cobalt — acceptable for occasional holes, but not for production work.

This set suits homeowners who drill mixed materials and need a single comprehensive kit. Anyone drilling stainless steel regularly should step up to a cobalt set like DEWALT’s M35/M42 option, because the TiN coating cannot be resharpened once worn.

💡 Tip: Use cutting oil and lower RPM when drilling stainless steel to extend bit life and reduce breakage.

Bottom line: A smart pick if you need one set for occasional stainless drilling among wood and plastic projects, but dedicated cobalt bits are the better investment for frequent metalwork.

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#06

Best Budget 1/4" Cobalt Bulk Pack

RCINDUS 1/4" Cobalt 15pk

90 /100
Kirk Score Outstanding
Pieces
15
Material
M35 Cobalt (5% Co)
Shank Type
Straight
Size Range
1/4 in. only
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Pros

  • Excellent quality-to-price ratio for bulk 1/4-inch cobalt bits.
  • Cleanly drills stainless sheet and mild steel tubing without walking.

Cons

  • Bits may snap after extended high-pressure use, particularly in thicker stainless.

Fifteen genuine M35 cobalt 1/4-inch bits offer the lowest per-bit cost for shops that drill repeated holes in stainless steel sheet and tube. The 135-degree split point bites quickly without a center punch, and the 5% cobalt alloy resists heat better than standard high-speed steel. Compared to the top pick's M42 build, these bits trade a bit of edge life for a much larger quantity at a budget-friendly price.

This set is built for fabricators who run through 1/4-inch bits on production stainless assemblies. Longevity under continuous heavy use can vary — occasional snapping has been noted — but the pack assumes some breakage and keeps spares close. Shops that value consumable cost per hole over maximum individual bit life will find the math works.

Bottom line: For welding shops and metal fabricators who burn through 1/4-inch bits and prioritize per-hole cost, this bulk pack offers a practical balance of cobalt quality and quantity.

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#07

Starter Set

DEWALT DW1354 TiN Set

96 /100
Kirk Score Outstanding
Pieces
14
Material
TiN Coated HSS
Shank Type
Straight
Size Range
1/16 in. to 1/2 in.
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Pros

  • Sharp right out of the box, making quick work of common household materials.
  • Case keeps 14 sizes organized and accessible for small projects.

Cons

  • When drilling stainless or applying pressure, small bits may snap and TiN edges lose sharpness.

Sharp and affordable, this 14-piece set excels at wood, plastic, and mild steel. TiN coating handles occasional light-gauge stainless, but edge retention drops under heat and small bits may snap under load. It’s outclassed by the 21-piece set in size range and value, and not a replacement for cobalt bits in regular stainless drilling.

Bottom line: For a new homeowner drilling wood, plastic, and mild steel, with only occasional thin stainless work, this set gets the job done at a low price. Keep a cobalt bit on hand for harder metal.

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#08

Small-Hole Cobalt

GMTOOLS 1/8" Cobalt 10pk

90 /100
Kirk Score Outstanding
Pieces
10
Material
M35 Cobalt Steel
Shank Type
Straight
Size Range
1/8 in. only
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Pros

  • Very affordable way to get genuine cobalt for small stainless holes
  • Bits stay sharp through multiple stainless holes when used with cutting oil and light pressure

Cons

  • 1/8-inch bits can snap on first use if handled with hand drills or inconsistent feed
  • Occasional missing pieces in the plastic case; double-check upon arrival

This 10-pack stocks genuine M35 cobalt for small stainless pilot holes at a bargain price. The bits hold an edge through multiple holes with proper oil and feed. The 1/8-inch size snaps easily if hand-drilled or fed unevenly—treat them as consumables. Some packs arrive missing a piece. As an affordable bulk stash where breakage is expected, it works.

Bottom line: For hobbyists drilling 1/8-inch pilot holes in stainless with a drill press and steady hand, this pack offers cheap cobalt where the occasional broken or missing bit won’t stop the job.

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#09

3/8 in. Cobalt

amoolo 3/8" Cobalt 5pk

91 /100
Kirk Score Outstanding
Pieces
5
Material
M35 Cobalt Steel
Shank Type
Round
Size Range
3/8 in. only
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Pros

  • Sharp M35 cobalt edges slice through stainless steel with low speed and cutting oil
  • Budget-friendly price makes cobalt accessible for occasional hard-metal jobs

Cons

  • Lateral pressure or hand-drill wobble can snap the bits on the first few holes

The M35 cobalt edges bite into hard metal cleanly when run at low speed with steady pressure and cutting oil. However, high brittleness means they can snap under side load — especially in a hand drill — so true economy depends on careful technique and a drill press.

Bottom line: This set fits budget-conscious metalworkers who use a drill press and accept that breakage may mean using multiple bits per project.

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#10

Impact Sheet Metal

Bosch TI5IM Impact Set

93 /100
Kirk Score Outstanding
Pieces
5
Material
TiN Coated HSS
Shank Type
Hex (impact rated)
Size Range
3/32 in. to 1/4 in.
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Pros

  • Impact-rated TiN coating powers through thin stainless and sheet metal with a no-skate tip.
  • 1/4-inch hex shank enables quick changes and fits into tight spaces frequented by mechanics.

Cons

  • Mechanic-length bits can't reach deep holes; impact driver torque may snap them on thicker stainless.

Quick-change hex shank cuts sheet metal and thin stainless with an impact driver — handy for tight spaces. Their short mechanic length and variable durability, though, restrict them to light-gauge metal; they're not built for deep stainless holes or prolonged hard-metal use.

Bottom line: For mechanics drilling sheet metal and thin stainless with an impact driver, these quick-change bits work within their reach limits — just don't expect deep holes or long life in tough stainless.

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#11

Thin Stainless Pilot

Bosch 7/64" TiN 2pk

91 /100
Kirk Score Outstanding
Pieces
2
Material
HSS with TiN coating
Shank Type
3-Flat
Size Range
7/64 in. only
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Pros

  • Budget-friendly 2-pack stays sharp through repeated light-duty drilling in thin metal and acrylic.
  • Self-starting point bites into thin stainless and plastic without walking, cutting prep time.

Cons

  • Not designed for stainless thicker than 1/8 inch; pushing beyond may cause premature dulling.

The Bosch TiN-coated 2-pack stays sharp through light-duty work in thin sheet metal, acrylic, and plastics. Its self-starting point bites without walking. But these bits are limited to 7/64-inch holes in material no thicker than 1/8 inch, and the package contains only two bits. Buyers needing a full set for varied stainless drilling will find this too narrow.

Bottom line: If your stainless drilling stays within 1/8-inch thickness and you need repeatable 7/64-inch holes, this 2-pack is a cost-effective choice. For thicker material, a cobalt set is the better path.

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#12

Aluminum Step Drill

ZELCAN Step Drill Set

89 /100
Kirk Score Excellent
Pieces
5
Material
HSS with TiN coating
Shank Type
1/4" Hex
Size Range
3/16 in. to 1-3/8 in.
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Pros

  • Broad 50-step size range handles most hole-enlarging tasks in plastic, aluminum, and thin mild steel.
  • Organized case and sharp bits make quick work of thin sheet metal (non-stainless).

Cons

  • Edges may dull after a single hole in stainless steel, making the set unsuitable for that material.

The ZELCAN step bit set drills cleanly in aluminum, thin mild steel, and plastic, with a wide 50-step range and a well-organized case. On stainless steel, the titanium coating breaks down quickly, dulling edges after just a few holes. Electricians and HVAC techs working with enclosures will appreciate it, but anyone drilling stainless steel should look to cobalt bits.

Bottom line: If your work centers on aluminum, plastic, or mild steel sheet and you never need to drill stainless, this set offers a wide size range and convenient case.

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#13

Fractional Variety

MACXCOIP 29pc Cobalt Set

88 /100
Kirk Score Excellent
Pieces
29
Material
M35 Cobalt Steel
Shank Type
Straight
Size Range
1/16 in. to 1/2 in.
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Pros

  • Comprehensive fractional sizing from 1/16 to 1/2 inch in a single set
  • Metal index box keeps bits organized and protected

Cons

  • Small-diameter bits can snap under moderate lateral pressure

The comprehensive fractional range from 1/16 to 1/2 inch and metal index box appeal to organized tool collectors. For stainless steel, the M35 cobalt edges may struggle with consistency — bits can skate or dull instead of cutting. This set suits occasional light-metal and wood drilling where full size coverage justifies the premium price, not production stainless work.

Bottom line: For the organized DIYer who wants every fractional size on hand for occasional wood and light-metal projects, the metal case and full range offset the limits on stainless duty.

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How to Choose

Material: Cobalt vs. Titanium Nitride

Genuine cobalt steel (M35 or M42) is the non-negotiable standard for stainless. The cobalt alloy retains its hardness even as friction heats the tip, while a titanium nitride coating on HSS softens and wears away under the same heat. Once the coating goes, the underlying high-speed steel dulls rapidly.

Cobalt bits can be resharpened multiple times, extending their useful life. TiN-coated bits cannot be re-sharpened without stripping the coating. If you're drilling more than a few holes, the upfront cost of cobalt translates to a lower cost-per-hole.

Point Style: Split-Point vs. Pilot Point

Split-point bits have a chisel edge that reduces walking and self-center on hard surfaces without a center punch. This geometry also requires less feed pressure, which is a major advantage when hand-drilling stainless. Pilot points start cleanly in softer metals but may walk on polished stainless if pressure is uneven.

The split-point's sharper cutting angle generates less heat at the point of contact, helping preserve the bit's edge. If you often skip a center punch, a split-point design will save you from ruined starts on stainless sheet.

Shank Type: 3-Flat, Hex, or Straight

A 3-flat shank adds three flattened sides that prevent the bit from spinning in the chuck, especially on larger diameters under high torque. Straight shanks are adequate for bits under ¼ inch but may slip during heavy stainless drilling. Hex shanks are mainly for impact drivers and quick-change chucks, but the bits are typically shorter and not suited for deep holes.

If you use a keyless chuck on a hand drill, a 3-flat shank can be the difference between a clean hole and a smoking, stuck bit. For drill press work, a straight shank is perfectly fine.

Size Range and Quantity

Large sets with every fractional size look appealing, but in practice you'll wear through the most-used diameters—1/8", 3/16", and 1/4"—long before the larger sizes see action. Buying bulk packs of those key sizes and a smaller set for the rest often provides more value.

Small-diameter bits under 1/8" are inherently fragile in any material. Treat them as consumables, keep spares, and never force them. A 10-pack of the same size can cost less than replacing a full set after a single broken bit.

Frequently Asked Questions