Best Cobalt Drill Bit Sets: Drill Through Hard Metals Faster

Drill smarter, not harder, with these top cobalt drill bit sets

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  • Product Network

    24 Products

  • Clock

    10 Hours

  • Reviews

    14 Reviews

How We Decided

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PUBLISHED ON November 5, 2019

While standard HSS (high-speed steel) drill bits are great for wood and soft metals, they literally won’t cut it when it comes to stainless steel and other heat-hardened metals. Cobalt drill bits are constructed out of stronger materials and are more durable and resistant to heat than average bits. They’re the perfect choice if you’re working with stainless steel. See below for our top picks of cobalt drill bit sets.

  • Best Overall
    Irwin 29-piece Drill Bit Set, M35 Cobalt Steel

    Heavy-duty drill bits constructed from industrial grade steel with five percent cobalt for improved resistance to heat and abrasion and web design for maximum strength and durability. Come in a range of sizes between 1/16 and 1/2 inch.


    Bits include 135-degree split point tips to eliminate walk and enable immediate drilling. Carry case includes rubber over-molding for increased protection against drops and damage.


    Some of the bit sizes are inaccurate and slightly smaller than listed. The latching system on the carry case is difficult and awkward to open.

  • Best Value
    Bosch Cobalt M42 Drill Bit Set

    High heat-resistant drill bits with eight percent cobalt alloy and surface-hardened, no-skate tips for maximum performance and durability. Available in a wide range of individual sizes and 14- or 21-piece mixed drill bit sets in a handy carry case.


    Drill bits include a thick web-helix design for extra stability during, particularly tough usage. Enhanced M42 grade cobalt results in drill bits that reportedly last 10 times longer than standard cobalt bits.


    Indexing on carrying case is difficult to read. The product is slightly more expensive than some of its rivals.

  • Honorable Mention
    DeWalt 14-piece Cobalt Pilot Point Drill Bit Set

    Set of 14 industrial-strength cobalt steel drill bits in a range of commonly used sizes from 1/16 to 3/8 inch. Specifically designed for use with hard metals, these bits include pilot point tips for accurate drilling, clean holes, and a reduction in locking up after breakthrough.


    Packaged in the heavy-duty case with interlocking hinge for guaranteed protection and labeled bit slots for ease of use and organization. The set includes a replacement for each of the three most common drill bit sizes.


    Only available in one set size. Some users describe performance of drill bits as aggressive and grabby.

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  • Extend the life of your cobalt drill bits by sharpening them after they become dull, but keep in mind you won’t be able to replicate a pilot point tip when doing so.
  • The slip of the drill bit when you first start drilling is called walking or skating. Choose drill bits with split point or pilot point tips to minimize this if accuracy is important.
  • Make sure you know what you’ll be using the drill bits for before choosing a set, so you can be sure you choose one with the right sizes.


Q: What is the difference between M35 and M42 cobalt steel?

A: M35 and M42 refer to the percentage of cobalt in the cobalt steel alloy. M35 is five percent cobalt whereas M42 has eight percent.

Q: Which is better: a cobalt or titanium drill bit?

A: Cobalt steel drill bits are ideal for use with hard metals, like cast iron or stainless steel, because they can be sharpened and have high heat resistance. Titanium bits cannot be sharpened but are equally hard and have anti-corrosive properties so they may provide superior performance with wood and softer metals.

Q: Do I need to use cutting oil with cobalt drill bits?

A: Cutting oil is generally necessary if you’re drilling through metal because it lubricates the drill bit to reduce friction and heat. It’s not necessary if you’re drilling other materials but is certainly a good idea when drilling hard metals in order to improve the lifespan of your drill bits.

Final Thoughts

Constructed in industrial-strength steel with five percent cobalt, the Irwin 29-piece Drill Bit Set, M35 Cobalt Steel is our top pick overall, while the Bosch Cobalt M42 Drill Bit Set is our best value set.