When it comes to drilling through tough materials like hardened steel and stainless steel, cobalt drill bits stand out for their durability and heat resistance. The best overall pick is the Cobalt Drill Bits Set for Hardened Metal and Stainless Steel, offering a comprehensive range for serious jobs. For those on a budget, the 13pcs Cobalt Drill Bits Set M35 HSS provides good performance at a lower cost. Meanwhile, the DEWALT Cobalt Alloy Steel Drill Bit Set excels in precision and longevity. The main tradeoffs involve balancing price, versatility, and durability—more expensive sets tend to last longer but may offer more bits than needed for casual projects. Continue reading for a detailed breakdown to find the right cobalt drill bits for your needs.
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Key Takeaways
- Top-performing sets combine durability with a versatile range of sizes for various project needs.
- Higher-quality cobalt drill bits often feature M35 high-speed steel for increased heat resistance and longevity.
- Sets with a storage case improve organization but may add to overall cost; consider your storage preference.
- Stepped or tapered bits are ideal for specific applications, but standard twist bits cover most needs.
- Price correlates strongly with durability and number of bits, though premium options may offer better performance for heavy use.
| Cobalt Drill Bits Set for Hardened Metal and Stainless Steel, 99 Pieces, M35 High Speed Steel Twist Jobber Drill Bits 1/16″-3/8″ with Storage Case |  | Best Overall for Versatility and Size Range | Material: M35 High Speed Steel | Number of Pieces: 99 | Sizes: 1/16″ to 3/8″ | VIEW ON AMAZON | See Our Full Breakdown |
| 13pcs Cobalt Drill Bits Set M35 HSS Jobber Drill Bits from 1/16″ to 1/4″ |  | Best for Precision and Portability | Set Size: 13 pieces | Material: M35 HSS with 5% cobalt | Range: 1/16″ to 1/4″ | VIEW ON AMAZON | See Our Full Breakdown |
| 115-Piece Cobalt Drill Bit Set M35 HSS Jobber Length |  | Best for Versatility and Large-Scale Projects | Number of Pieces: 115 | Fractional Sizes: 1/16″ to 1/2″ | Letter Sizes: A to Z | VIEW ON AMAZON | See Our Full Breakdown |
| 29-Piece Cobalt Drill Bit Set (1/16″ – 1/2″) M35 HSS Jobber Length |  | Best for Mid-Range Versatility and Tough Materials | Number of Pieces: 29 | Sizes: 1/16″ to 1/2″ | Material: M35 Cobalt HSS | VIEW ON AMAZON | See Our Full Breakdown |
| DEWALT Cobalt Alloy Steel Drill Bit Set with Pilot Point, 14-Piece |  | Best for Durability and Easy Organization | Material: Cobalt Alloy Steel | Number of Pieces: 14 | Features: Pilot Point, Connectable storage, Clear lid | VIEW ON AMAZON | See Our Full Breakdown |
| 1/8″ Cobalt Drill Bit Set, 20 Pieces, HSS M35 Metal Drill Bits for Steel, Stainless Steel, Cast Iron, Plastic, and Wood |  | Best Overall for Versatility and Value | Diameter: 1/8 inch | Number of Pieces: 20 | Material: M35 High Speed Steel with 5% Cobalt | VIEW ON AMAZON | See Our Full Breakdown |
| Crosstar M35 Cobalt Drill Bit Set, 21 pcs, 1/16″-1/2″ |  | Best for Heavy-Duty Metalworking | Material: M35 cobalt high-speed steel | Coating: TiAlN (Titanium Aluminum Nitride) | Number of Pieces: 21 | VIEW ON AMAZON | See Our Full Breakdown |
| CaRoller 29-Piece Cobalt Drill Bit Set – M35 Steel, Durable and Versatile |  | Best for General Purpose and DIY Enthusiasts | Number of Pieces: 29 | Material: M35 Cobalt Steel | Bit Sizes: 1/16″ to 1/2″ | VIEW ON AMAZON | See Our Full Breakdown |
| BOSCH CO14B 14-Piece Cobalt Drill Bit Set with Case |  | Best for Heavy-Duty Metal Drilling | Material: 8% Cobalt Alloy (M42) | Number of Pieces: 14 | Sizes: 1/16″ to 1/2″ | VIEW ON AMAZON | See Our Full Breakdown |
| 13-Piece Cobalt Drill Bit Set (1/16″-1/4″) M35 HSS Jobber Length |  | Best Budget-Friendly Starter Set | Number of Pieces: 13 | Bit Sizes: 1/16″ to 1/4″ | Material: M35 Cobalt HSS | VIEW ON AMAZON | See Our Full Breakdown |
| Metric Cobalt Drill Bits Set 1.5-6.5mm, 13PCS, M35 High-Speed Steel |  | Best Overall for Versatility and Precision | Material: M35 high-speed steel with 5% cobalt | Number of Pieces: 13 | Range: 1.5mm to 6.5mm | VIEW ON AMAZON | See Our Full Breakdown |
| Drill America 29 Piece Cobalt Stepped Point Drill Bit Set in Round Case with Gold Oxide Finish for Drilling Acrylic, Steel, Hard Metals |  | Best for Range and Portability | Number of Pieces: 29 | Finish: Gold Oxide | Material: Cobalt | VIEW ON AMAZON | See Our Full Breakdown |
| GMTOOLS 15-Piece Cobalt Drill Bit Set, M35 HSS, 135° Tip, Jobber Length for Metal, Wood, Plastic |  | Best for Versatility in Tough Materials | Material: M35 High Speed Steel with 5% Cobalt | Tip Angle: 135° | Set Includes: 15 drill bits | VIEW ON AMAZON | See Our Full Breakdown |
| cobalt drill bit | Material | Number of Pieces |
|---|---|---|
| Cobalt Drill Bits Set for Hard | M35 High Speed Steel | 99 |
| 13pcs Cobalt Drill Bits Set M3 | M35 HSS with 5% cobalt | — |
| 115-Piece Cobalt Drill Bit Set | M35 Cobalt HSS | 115 |
| 29-Piece Cobalt Drill Bit Set | M35 Cobalt HSS | 29 |
| DEWALT Cobalt Alloy Steel Dril | Cobalt Alloy Steel | 14 |
| 1/8" Cobalt Drill Bit Set | M35 High Speed Steel with 5% Cobalt | 20 |
| Crosstar M35 Cobalt Drill Bit | M35 cobalt high-speed steel | 21 |
| CaRoller 29-Piece Cobalt Drill | M35 Cobalt Steel | 29 |
| BOSCH CO14B 14-Piece Cobalt Dr | 8% Cobalt Alloy (M42) | 14 |
| 13-Piece Cobalt Drill Bit Set | M35 Cobalt HSS | 13 |
| Metric Cobalt Drill Bits Set 1 | M35 high-speed steel with 5% cobalt | 13 |
| Drill America 29 Piece Cobalt | Cobalt | 29 |
| GMTOOLS 15-Piece Cobalt Drill | M35 High Speed Steel with 5% Cobalt | — |
More Details on Our Top Picks
Cobalt Drill Bits Set for Hardened Metal and Stainless Steel, 99 Pieces, M35 High Speed Steel Twist Jobber Drill Bits 1/16″-3/8″ with Storage Case
This comprehensive 99-piece set stands out for its extensive size selection, making it ideal for both professional workshops and serious DIY projects. Crafted from M35 high-speed steel, these bits deliver exceptional hardness—up to 67 HRC—allowing them to effectively drill through hardened metals, stainless steel, and cast iron, outperforming smaller or less durable sets. The included labeled plastic case keeps everything organized, a feature that busy users will appreciate. Compared to smaller sets like the 13-piece option, this one offers more versatility, though it comes at a higher price and requires careful handling to avoid dulling the bits. Tradeoffs include cost and the need for low-speed drilling and cutting fluid for optimal results. This set makes the most sense for users needing a broad range of sizes and maximum durability, willing to invest in high-quality tools for tough materials.
Pros:- Extensive size range for diverse applications
- High hardness and durability from M35 steel
- Convenient, labeled storage case
Cons:- Relatively expensive compared to smaller sets
- Requires low-speed drilling and cooling for best performance
Best for: Professional metalworkers and serious DIYers needing a complete, durable set for varied projects
Not ideal for: Casual users or occasional drillers who only need a few sizes or lighter-duty bits, due to its cost and size
- Material:M35 High Speed Steel
- Number of Pieces:99
- Sizes:1/16″ to 3/8″
- Packaging:Plastic storage case
- Hardness:Up to 67 HRC
- Usage:Hardened metal, stainless steel, cast iron, aluminum, plastic, wood
Our verdict“This set offers unmatched size variety and durability, ideal for professionals or enthusiasts tackling tough materials regularly.”
13pcs Cobalt Drill Bits Set M35 HSS Jobber Drill Bits from 1/16″ to 1/4″
This 13-piece set emphasizes precision with its 135° split point tip, making it well-suited for clean, accurate drilling in harder materials like metals, plastics, and wood. Made from M35 cobalt HSS, it offers improved heat and wear resistance over standard steel bits, but compared to the 99-piece set, it covers a narrower size range, limiting versatility for larger or more varied projects. The included sturdy storage box ensures organization, which is especially useful for professionals on the go or serious hobbyists. While the cobalt content enhances durability, some users report that the bits may not last as long as higher-end, larger sets, especially under heavy use. The tradeoff here is a focus on precision and portability at the expense of range and long-term durability. This pick makes the most sense for users who value exact drilling and limited size needs, rather than extensive project variety.
Pros:- Precise 135° split point for accurate drilling
- Enhanced heat and wear resistance from cobalt
- Compact, portable storage box
Cons:- Limited size range compared to larger sets
- Potential durability issues under frequent heavy use
Best for: DIYers and professionals needing precise, reliable bits for specific tasks in metals or plastics
Not ideal for: Users requiring a broad size range or heavy-duty, long-term drilling in tough materials, where larger sets or higher durability are necessary
- Set Size:13 pieces
- Material:M35 HSS with 5% cobalt
- Range:1/16″ to 1/4″
- Tip Angle:135° split point
- Included:Storage box
Our verdict“This set is perfect for precise, small-scale projects where exact hole placement is critical, but less so for heavy-duty or extensive drilling needs.”
115-Piece Cobalt Drill Bit Set M35 HSS Jobber Length
This expansive 115-piece set offers a broad spectrum of sizes, from 1/16” to 1/2”, making it suitable for a wide array of projects, including drilling through stainless steel, cast iron, and aluminum. Crafted from M35 cobalt HSS, these bits combine durability with sharpness, enabling efficient, fast cuts thanks to their 135-degree point tip. The variety of sizes—covering fractional, letter, and numbered measurements—makes this set extremely versatile, especially when compared to smaller or less organized options. However, the weight and bulk of the set could pose challenges for small or delicate projects, and the absence of bits for very soft materials might limit some applications. The tradeoff lies in handling a heavier collection for the benefit of extensive size options and durability. It’s ideal for professionals or serious hobbyists handling diverse materials frequently.
Pros:- Wide variety of sizes for maximum versatility
- Durable, sharp cobalt construction
- Efficient, fast cutting with 135° point
Cons:- Heavy and bulky for small projects
- Lacks bits for very soft materials
Best for: Professional workshops or large-scale DIYers needing a comprehensive, organized set for mixed materials
Not ideal for: Casual users or those with limited space, due to the weight and size of the full set
- Number of Pieces:115
- Fractional Sizes:1/16″ to 1/2″
- Letter Sizes:A to Z
- Numbered Sizes:#1 to #60
- Material:M35 Cobalt HSS
- Application:Hard metals, plastics, wood
Our verdict“This set excels in offering extensive sizing options and durability, perfect for frequent, varied drilling tasks in a professional setting.”
29-Piece Cobalt Drill Bit Set (1/16″ – 1/2″) M35 HSS Jobber Length
This 29-piece set strikes a balance between size variety and manageable weight, covering from 1/16” to 1/2”. Made from M35 cobalt HSS, the bits feature a sharp 135-degree tip for effective, precise drilling in hardened metals, stainless steel, and cast iron. The included storage case keeps organization straightforward, making it easier to access sizes quickly. While it doesn’t offer the sheer range of the 115-piece set, it provides enough versatility for most demanding projects without the bulk. Compared to the smaller 13-piece set, this option is better suited for users who need more sizes but don’t require the extensive options of larger collections. The main tradeoff involves paying a premium for quality and range, with some risk of brittleness if mishandled. It makes sense for users who want a durable, versatile set without excess bulk.
Pros:- Good range of sizes for versatile use
- Durable, sharp cobalt bits for tough materials
- Convenient storage case
Cons:- Higher price point than standard bits
- Potential brittleness with mishandling
Best for: Serious hobbyists or professionals needing a reliable, mid-sized set for tough materials
Not ideal for: Light-duty or infrequent drillers who only need a handful of sizes or softer materials, due to its cost and size
- Number of Pieces:29
- Sizes:1/16″ to 1/2″
- Material:M35 Cobalt HSS
- Application:Hardened metals, stainless steel, cast iron, wood, plastics
- Tip Angle:135°
Our verdict“This set offers a strong combination of size variety and durability, ideal for demanding projects without the bulk of larger sets.”
DEWALT Cobalt Alloy Steel Drill Bit Set with Pilot Point, 14-Piece
This 14-piece DEWALT set emphasizes durability with cobalt alloy steel and features pilot points that enhance precision and reduce walking during drilling. The connectable storage system with a clear lid simplifies organization and quick access, especially for users managing multiple sets. While the set’s limited number of bits restricts size options compared to larger collections, it compensates with high-quality construction suitable for drilling in wood, metal, and even i-beams. The compact storage system is a plus for professionals on the move, but the size may be limiting for extensive projects. The main tradeoff involves fewer bits and the need for a compatible storage system for full benefit. This set is best suited for users who prioritize durability, organization, and straightforward tasks over extensive size coverage.
Pros:- Durable cobalt alloy steel construction
- Pilot point for precise, walking-free drilling
- Connectable, clear storage lid
Cons:- Limited number of bits for extensive projects
- Requires compatible storage system for best organization
Best for: Contractors and serious DIYers valuing durability and quick organization for medium-sized projects
Not ideal for: Users needing a broad range of sizes or infrequent drillers who prefer simpler, less durable options
- Material:Cobalt Alloy Steel
- Number of Pieces:14
- Features:Pilot Point, Connectable storage, Clear lid
- Application:Wood, metal, i-beams
- Storage System:Connectable, with lid
Our verdict“This set is excellent for demanding, organized work environments where durability and quick access are priorities, but less so for large-scale or highly varied projects.”
1/8″ Cobalt Drill Bit Set, 20 Pieces, HSS M35 Metal Drill Bits for Steel, Stainless Steel, Cast Iron, Plastic, and Wood
This set stands out for offering a comprehensive variety of sizes in a durable plastic case, making it ideal for both professional and serious DIY use. The high-quality M35 cobalt steel ensures durability when drilling through hard metals like stainless steel and cast iron, surpassing standard HSS bits in lifespan and performance. Its self-centering split point minimizes walking, which is especially helpful for precise work. Compared to smaller sets, this provides more options without sacrificing quality, though it does come at a higher cost. It’s less effective on softer materials like wood or plastic, where cheaper bits might suffice. Overall, this set offers a blend of versatility, durability, and value for users who frequently drill hard metals and need a reliable, all-in-one kit.
Pros:- High-quality M35 cobalt steel ensures durability and performance
- Includes 20 bits for a wide range of applications
- Self-centering split point reduces walking for accurate drilling
- Convenient plastic storage case for organization
Cons:- More expensive than standard HSS drill bits
- Less effective on softer materials like wood and plastic
Best for: Experienced DIYers or professionals needing a versatile set for drilling through various hard metals and tough materials.
Not ideal for: Casual hobbyists or those primarily working with softer materials like wood or plastic, due to its focus on hard metals and higher cost.
- Diameter:1/8 inch
- Number of Pieces:20
- Material:M35 High Speed Steel with 5% Cobalt
- Point Angle:135 degrees
- Application:Hardened metal, stainless steel, cast iron, plastic, wood
- Storage:Plastic case
Our verdict“This set is ideal for users who need a durable, versatile collection of cobalt drill bits for hard metals and demanding applications.”
Crosstar M35 Cobalt Drill Bit Set, 21 pcs, 1/16″-1/2″
This set is tailored for professionals tackling tough metals, featuring advanced TiAlN coating for heat resistance that surpasses the basic cobalt bits in durability. The triple-flute design enhances chip ejection, leading to cleaner cuts and faster progress, especially when drilling through stainless steel or titanium alloys. Its three-flat shank prevents slipping, ensuring consistent torque transfer during demanding tasks. Compared to the 1/8″ Cobalt Set, this set offers a broader size range and better heat management but comes with a higher price tag. It’s not suitable for softer materials, where simpler bits might be more cost-effective. This pick makes sense for those who prioritize longevity and performance in heavy-duty metalworking, especially in a professional setting.
Pros:- TiAlN coating offers excellent heat resistance
- Triple-flute design improves chip removal and accuracy
- Secure three-flat shank prevents slipping under heavy loads
- Range from 1/16″ to 1/2″ covers most common sizes in metalwork
Cons:- Higher cost compared to basic cobalt sets
- Primarily designed for professional or heavy-duty use, less suited for occasional home projects
Best for: Metal fabricators and professionals working on hardened steels or titanium who need reliable, heat-resistant bits.
Not ideal for: Casual DIYers or hobbyists focusing mainly on softer materials, as the precision and cost may be overkill for simple tasks.
- Material:M35 cobalt high-speed steel
- Coating:TiAlN (Titanium Aluminum Nitride)
- Number of Pieces:21
- Range:1/16″ to 1/2″
- Flute Design:Triple-flute (sizes 3/32″ and up), Two-flute (sizes 1/16″ to 7/64″)
- Shank:Three-flat
Our verdict“This set excels for demanding metalworking tasks requiring heat resistance and durability, making it ideal for professionals or serious enthusiasts.”
CaRoller 29-Piece Cobalt Drill Bit Set – M35 Steel, Durable and Versatile
This 29-piece set offers a broad selection of sizes in a sturdy case, making it suitable for both professional and DIY projects involving steel, wood, and plastic. Constructed from durable M35 cobalt steel, these bits handle tough materials with ease, though they are not as specialized as the Crosstar set for extreme heat or heavy-duty use. The amber coating provides some corrosion resistance, and the round straight shank ensures compatibility with most drills. Compared to smaller, more specialized sets, this one emphasizes versatility at a slightly higher price point, but it requires proper handling to keep the bits sharp over time. It’s a good all-around choice for users who want reliable bits for multiple materials without breaking the bank.
Pros:- Durable M35 cobalt steel construction
- Includes a wide range of sizes for multiple materials
- Portable, ergonomic carrying case with clip
- Suitable for steel, wood, plastic, and sheet metal
Cons:- Requires careful handling to maintain sharpness
- Not optimized for extreme heat or very hard metals
Best for: DIYers and small workshops needing a versatile set for drilling steel, wood, and plastics with ease.
Not ideal for: Heavy-duty industrial users or professionals drilling extensively into hardened metals where specialized, high-performance bits are required.
- Number of Pieces:29
- Material:M35 Cobalt Steel
- Bit Sizes:1/16″ to 1/2″
- Coating:Amber
- Shank Type:Round straight
- Point Angle:135-degree split point
Our verdict“This set offers a flexible, durable option for DIY projects and light professional work across various materials.”
BOSCH CO14B 14-Piece Cobalt Drill Bit Set with Case
This Bosch set is tailored for demanding metalworking, featuring high heat resistance with 8% cobalt alloy and a surface-hardened tip for extended lifespan. Its thick web-helix design provides stability during drilling into hardened metals like stainless steel and cast iron, making it a strong competitor against the CaRoller set. The variety of sizes allows for multiple applications, though the set is more limited in number compared to larger options. It’s less suited for softer materials, where a less specialized set could suffice. This set makes the most sense for users who need a reliable, durable set for frequent, tough metal drilling, especially when working with stainless steel or titanium.
Pros:- High heat resistance with 8% cobalt alloy
- Surface-hardened tip enhances durability
- Thick web-helix design for stability
- Includes a variety of essential sizes
Cons:- More expensive compared to general-purpose sets
- Limited number of pieces for broader size coverage
Best for: Industrial or professional users requiring a dependable set for frequent drilling into hardened metals like stainless steel and cast iron.
Not ideal for: Home hobbyists or casual users focusing on softer materials, due to its premium price and specific application focus.
- Material:8% Cobalt Alloy (M42)
- Number of Pieces:14
- Sizes:1/16″ to 1/2″
- Features:High heat resistance, surface-hardened tip, thick web-helix
Our verdict“This set provides excellent durability and performance for heavy-duty metalworking, fitting for those drilling frequently into hardened steels.”
13-Piece Cobalt Drill Bit Set (1/16″-1/4″) M35 HSS Jobber Length
This compact set offers essential sizes for drilling into hardened metals, stainless steel, cast iron, and plastics, making it a practical choice for those new to cobalt bits or with limited needs. The M35 cobalt HSS ensures better longevity than standard HSS, and the 135-degree point helps with precise, efficient cuts. The included storage case keeps things organized, though the limited size range might restrict more extensive projects. Compared to the larger CaRoller or Crosstar sets, this one sacrifices variety for affordability. It’s best suited for occasional use or small projects where the core sizes are sufficient, but not for heavy, ongoing work.
Pros:- Durable M35 cobalt HSS for longer lifespan
- Includes essential sizes for common tasks
- Self-centering tip for accurate drilling
- Compact storage case for easy organization
Cons:- Limited size range may restrict larger or more varied projects
- Less suitable for frequent heavy-duty use
Best for: Home DIYers or beginners just starting with cobalt drill bits for small projects involving steel or cast iron.
Not ideal for: Heavy-duty professionals or users needing a wide range of sizes for extensive or industrial applications.
- Number of Pieces:13
- Bit Sizes:1/16″ to 1/4″
- Material:M35 Cobalt HSS
- Point Angle:135 degrees
- Application:Hardened metals, stainless steel, cast iron, plastics
- Storage:Plastic case with size indexes
Our verdict“This set provides a reliable, affordable option for beginners or occasional users focusing on smaller, straightforward drilling tasks.”
Metric Cobalt Drill Bits Set 1.5-6.5mm, 13PCS, M35 High-Speed Steel
This set stands out for its broad size range and high-quality M35 cobalt construction, making it a reliable choice for drilling hard metals like stainless steel and cast iron. Compared with the 29-piece Cobalt Stepped Point Set, this set offers more precise control with smaller sizes, ideal for detailed projects. Its heat resistance and wear resistance are excellent for frequent use, but it comes at a higher price point and requires a compatible drill to maximize performance. The set’s durability and wide applicability make it suitable for professional workshops or serious DIYers who need consistent results across various materials.
Pros:- Highly durable with excellent wear resistance
- Versatile for drilling various hard metals
- Includes a wide range of sizes for different tasks
Cons:- May be more expensive than standard drill bits
- Requires compatible drill for optimal use
Best for: Metal fabrication professionals and serious DIYers needing a versatile set for precise, hard-metal drilling
Not ideal for: Casual hobbyists or those working mostly with soft materials, since the set’s cost and focus on hard metals may be overkill
- Material:M35 high-speed steel with 5% cobalt
- Number of Pieces:13
- Range:1.5mm to 6.5mm
- Item Weight:0.13 kg
- Suitable Materials:Stainless steel, cast iron, copper, aluminum
- Heat Resistance:High
Our verdict“This set offers professional-grade durability and versatility, making it ideal for demanding metalworking tasks.”
Drill America 29 Piece Cobalt Stepped Point Drill Bit Set in Round Case with Gold Oxide Finish for Drilling Acrylic, Steel, Hard Metals
This set excels by combining a large variety of sizes with a durable, water-resistant case, making it especially suitable for on-the-go projects and versatile applications. Unlike the smaller 13-piece set, its stepped point design speeds up drilling and reduces heat buildup, extending the lifespan of each bit. While the gold oxide finish enhances durability, it requires careful handling to prevent breakage, and the higher cost may be a concern for occasional users. This set makes a strong choice for professionals and hobbyists who need a broad spectrum of sizes and reliable performance in different environments.
Pros:- High-quality cobalt construction for durability
- Includes a wide range of sizes for versatile use
- Durable, water-resistant case for portability
Cons:- May be more expensive than standard drill bits
- Requires proper handling to prevent breakage
- Not suitable for very soft materials
Best for: Contractors and technicians needing a comprehensive, portable set for various metal and plastic drilling tasks
Not ideal for: Light-duty users or those working primarily with very soft materials, as cobalt bits are over-spec for such applications and the set’s price reflects its durability
- Number of Pieces:29
- Finish:Gold Oxide
- Material:Cobalt
- Shank Type:3-flat shank; round shank for sizes 11/64″ and smaller
- Included Sizes:1/16″ to 1/2″ in 64ths
- Angle:135 degrees
- Case Type:Round, water-resistant, shatterproof
Our verdict“This set offers excellent versatility and portability, ideal for professionals needing a broad range of sizes in demanding environments.”
GMTOOLS 15-Piece Cobalt Drill Bit Set, M35 HSS, 135° Tip, Jobber Length for Metal, Wood, Plastic
This set is well-suited for those who need a balance of toughness and variety, featuring a 135° split tip for faster, more precise drilling into hardened metals, cast iron, and stainless steel. Compared with the larger 29-piece set, GMTOOLS’ offering is more compact but still covers essential sizes for many projects. The gold oxide finish enhances lifespan, but cobalt bits can be brittle if mishandled, so careful operation is necessary. It’s an ideal choice for users who frequently switch between metal, wood, and plastic, and appreciate organized storage for efficiency.
Pros:- High-quality cobalt construction for durability
- Includes a variety of sizes for versatile use
- Organized storage case for easy access
Cons:- Set may be more costly than basic bits
- Cobalt bits can be brittle if mishandled
- Not suitable for very soft materials
Best for: Professional craftsmen and serious DIYers working across multiple materials needing a reliable, organized set
Not ideal for: Beginners or casual users who only work with softer materials, as cobalt bits are more expensive and require careful handling
- Material:M35 High Speed Steel with 5% Cobalt
- Tip Angle:135°
- Set Includes:15 drill bits
- Shank Type:Round straight
- Finish:Gold oxide
- Application:Hardened metals, cast iron, stainless steel, plastic, wood
Our verdict“This set balances durability and variety, making it well-suited for demanding tasks across diverse materials.”
How We Picked
The products in this roundup were evaluated based on performance, build quality, and versatility. Priority was given to sets with a broad size range suitable for different applications, especially for drilling hardened steel and stainless steel. We also considered ease of use, durability, and whether the sets include features like storage cases or specialized tips. Cost-effectiveness was factored in, but higher-priced options were included when they demonstrated clear advantages in longevity or precision. Ultimately, the ranking reflects the best value for different types of users—whether DIYers, professionals, or those requiring specialized bits.Factors to Consider When Choosing Cobalt Drill Bits
Choosing the right cobalt drill bits involves understanding several key factors that impact performance and longevity. While price is often a consideration, the specific material, bit design, and set features can make a significant difference in how well the bits perform over time. Making an informed choice requires evaluating your typical projects, the materials you’ll drill into, and how often you’ll need to replace bits. Here are some critical factors to consider:Material Quality and Steel Grade
The most durable cobalt drill bits are made from M35 high-speed steel, which offers excellent heat resistance and wear properties. Cheaper bits may use lower-grade steel, which dulls faster and risks breaking under stress. For frequent heavy-duty use, investing in M35 bits ensures longer lifespan and better performance, especially on hardened metals.
Bit Size Range and Set Composition
Consider the variety of sizes included in a set. If you often work on different projects, a larger range of sizes provides more flexibility without needing multiple purchases. However, if you only do specific tasks, a smaller, focused set might be more economical. Pay attention to the availability of common sizes like 1/8″ and 3/8″ for maximum utility.
Tip Design and Specialty Features
Features like pilot points or tapered tips improve drilling accuracy and reduce walking, especially on tough metals. Some sets include stepped or tapered bits suited for specialized tasks like countersinking or hole enlargement. Choosing the right tip design can save time and reduce frustration in precise projects.
Durability and Longevity
While initial cost matters, the ability of a bit to withstand repeated use on hardened steel justifies higher prices. Look for bits with reinforced shanks and heat-treated coatings to prevent breakage and dulling. Remember that investing in higher-quality bits can lower replacement frequency and overall costs over time.
Storage and Organization
Having a dedicated case or organizer helps keep bits accessible and protects them from damage. Consider sets with labeled compartments for easier selection during work. Good organization can also extend the lifespan of your bits by preventing unnecessary impacts and wear.
Frequently Asked Questions
How do I know if a cobalt drill bit is suitable for stainless steel?
Most cobalt drill bits made from M35 high-speed steel are designed for stainless steel, thanks to their heat resistance and toughness. Check the product specifications to confirm that the bits are rated for hard metals. Using bits specifically labeled for stainless steel ensures you get the best performance and longevity in your drilling tasks.
Can I use cobalt drill bits on wood or plastic?
Yes, cobalt drill bits can be used on wood and plastic, but they are primarily designed for metal, especially hardened steels. For softer materials, standard high-speed steel or titanium bits may be sufficient and more economical. Using cobalt bits on softer materials may lead to unnecessary dulling or damage, so reserve them for demanding metalwork.
Are cobalt drill bits compatible with standard drill chucks?
Most cobalt drill bits feature shanks that fit standard drill chucks, typically 3/8″ or 1/2″. Always verify the shank size before purchasing, especially if your drill has a specific chuck. Using bits with compatible shanks ensures a secure fit and optimal drilling performance without slipping or damage.
How often should I replace cobalt drill bits?
The lifespan of cobalt drill bits depends on usage frequency and material hardness. With proper use, they can last for hundreds of holes, but signs of dulling or chipping indicate it’s time for replacement. Regularly inspect the bits for wear and replace them when they no longer cut cleanly or cause excessive heat buildup.
What are the benefits of step or tapered cobalt drill bits?
Step or tapered bits are designed for specific tasks like enlarging holes or countersinking, offering precision and efficiency. They reduce the need for multiple tools and can make complex jobs easier. However, they may not be suitable for general-purpose drilling, so consider your typical projects before choosing these specialized bits.
Conclusion
For general metalworking and heavy-duty tasks, the best overall choice is the Cobalt Drill Bits Set for Hardened Metal and Stainless Steel, offering a broad range of sizes and reliable performance. Budget-conscious DIYers may find the 13pcs Cobalt Drill Bits Set M35 HSS provides solid value without sacrificing too much durability. Professionals seeking the highest longevity and precision should consider premium options like the DEWALT Cobalt Alloy Steel Drill Bit Set. Beginners or occasional users can start with smaller, focused sets, while those working on specialized projects might prefer bits with specific features like stepped tips. Ultimately, matching your project scope and frequency with the right set will ensure the best results and long-term satisfaction.
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