Drilling through hard steel is a task that demands the right tools. Standard drill bits simply won’t cut it, literally. To penetrate tough metals like stainless steel, hardened alloys, or cast iron without dulling your bit instantly or risking breakage, you need specialized drill bits made from superior materials and featuring advanced coatings and geometries. This comprehensive guide reviews the best drill bits for hard steel, helping you make an informed decision for your next challenging project.
Quick Product Comparison
Our Top 5 Best Drill Bits For Hard Steel Reviews – Expert Tested & Recommended
1. toolant Cobalt Drill Bit Set for Metal and Steel , Titanium Aluminum Nitride Coated with Bullet …
The toolant cobalt drill bit set for metal and steel, titanium aluminum nitride coated with bullet offers exceptional quality and performance. This 21-piece set is specifically designed for drilling through hard metals and steel, ensuring durability and precision for demanding tasks. It’s a professional-grade collection built to withstand rigorous use.
Key Features That Stand Out
- ✓ Titanium Aluminum Nitride (TiAlN) Coating: Increases surface hardness to 89HRC and provides outstanding heat resistance, allowing bits to cut faster and stay sharp longer.
- ✓ Comprehensive 21-Piece Set: Includes metal drill bits in a wide range of common sizes: 1/16″ (x2), 5/64″ (x2), 3/32″ (x2), 7/64″ (x2), 1/8″ (x2), 9/64″, 5/32″, 11/64″, 3/16″, 13/64″, and more.
- ✓ Cobalt Material Construction: Ensures superior strength and longevity, making these bits highly effective for drilling through hard steel, stainless steel, and other tough alloys.
- ✓ Optimized Bullet-Point Design: Facilitates faster starts and reduces bit walking, leading to cleaner and more accurate holes.
Why We Recommend It
Its advanced TiAlN coating combined with robust cobalt construction makes this set ideal for extreme drilling conditions. It offers a significant performance boost and extended lifespan compared to standard bits, translating into fewer replacements and more efficient work. This set delivers consistent, reliable results on the toughest materials.
Best For
Professionals, metal fabricators, and serious DIYers tackling frequent projects involving drilling through hardened steel, stainless steel, cast iron, and other challenging metals where maximum durability, cutting efficiency, and longevity are paramount.
Pros and Cons
Pros:
- Superior TiAlN coating drastically extends bit life and heat resistance.
- Cobalt material ensures strength for drilling hard steel and tough alloys.
- Comprehensive 21-piece set offers versatility for various applications.
- Excellent durability and reliability for consistent high-performance.
Cons:
- Higher initial cost compared to basic HSS sets.
- May require specific drilling techniques (e.g., lower speed, lubricant) for optimal results on extremely hard materials.
Customer Reviews
Customer Review: “I’ve been struggling with drilling through some old railroad ties for a project, and these toolant cobalt bits sliced right through. The TiAlN coating really makes a difference; they stayed cool and sharp. Definitely worth the investment for any tough drilling job.” – Sarah L.
Customer Review: “Fantastic set for the price. I do a lot of automotive work and frequently need to drill into chassis components. These bits perform flawlessly on hardened bolts and thick steel. The variety of sizes is perfect, and they hold up much better than my previous titanium sets.” – Mark T.
2. DEWALT Titanium Nitride Pilot Point Drill Bit Set for Hard Steel, 21-Piece
The DEWALT Titanium Nitride Pilot Point Drill Bit Set, a robust 21-piece collection, is engineered for superior performance when drilling through hard steel and other tough materials. Featuring a specialized Titanium Nitride coating, these bits are built to last and deliver clean, precise holes. This set provides the reliability and precision expected from a leading brand.
Key Features That Stand Out
- ✓ Titanium Nitride (TiN) Coating: Enhances surface hardness and durability, significantly reducing friction and heat buildup during drilling, leading to longer bit life.
- ✓ Pilot Point Tip Design: Allows for immediate contact and cleaner holes, effectively preventing bit walking and ensuring accurate starts without the need for a pilot hole.
- ✓ Versatile 21-Piece Set: Offers a wide range of popular sizes, making it suitable for various drilling applications in metal and wood.
- ✓ Designed for Longer Life: Optimized flute geometry and TiN coating ensure extended bit life and efficient material removal in demanding tasks.
Why We Recommend It
DEWALT’s reputation for quality, combined with the effective TiN coating and the innovative Pilot Point tip, makes this set a reliable choice for accurate and long-lasting performance on hard metals. It delivers consistent, professional results for both pros and serious DIYers.
Best For
General contractors, fabricators, electricians, and serious DIY enthusiasts who need a dependable and long-lasting set of drill bits for regular use on hard steel, stainless steel, aluminum, and other challenging ferrous metals.
Pros and Cons
Pros:
- Pilot Point tip prevents walking and ensures clean, accurate holes from the start.
- Titanium Nitride coating enhances durability and significantly extends bit life.
- From a recognized brand known for quality and reliability in power tools and accessories.
- Suitable for a wide range of metal drilling applications, including hard steel.
Cons:
- Not as inherently heat resistant as pure cobalt bits for continuous, extreme heavy-duty use.
- Price point may be higher than entry-level HSS sets without coatings.
Customer Reviews
Customer Review: “This is an excellent drill bit set from DeWalt. I’d been eyeing it for a long time, waiting for the price to drop, and it was definitely worth the wait. Once it went on sale, I picked it up, and I’m glad I finally did—great quality and performance.” – Verified Purchaser
Customer Review: “I’ve had cheaper sets that dull out quickly on mild steel, but these DEWALT bits chew through even thick angle iron with no problem. The pilot point is a game-changer for accuracy. Highly recommend for anyone working with metal frequently.” – John P.
3. BOSCH 14-Piece Cobalt M42 Three-Flat Shank Drill Bits for Hard Steel and Stainless
The BOSCH 14-Piece Cobalt M42 Three-Flat Shank Drill Bit Set is a premium collection specifically engineered for drilling into hard steel and stainless steel. These upgraded M42 Cobalt jobber-length bits boast exceptional durability and superior heat resistance, ensuring reliable performance in the toughest materials without a premium price tag.
Key Features That Stand Out
- ✓ M42 Cobalt Alloy Material: Contains 8% Cobalt alloy, delivering up to 10 times the life compared to standard bits, especially in high-heat applications.
- ✓ Three-Flat Shank Design: Provides a secure grip in drill chucks, effectively preventing bit slippage and ensuring maximum power transfer and control.
- ✓ High-Heat Resistant Bits: Engineered to withstand elevated temperatures for extended periods, making them ideal for drilling through hardened metals.
- ✓ Hardened Surface: Specifically optimized for drilling tough materials like stainless steel and other challenging alloys.
Why We Recommend It
Bosch delivers professional-grade performance with these M42 cobalt bits. Their high cobalt content and three-flat shank make them incredibly robust and efficient for challenging materials, offering excellent value for their longevity and performance on hard steel and stainless steel.
Best For
Metalworkers, plumbers, mechanics, and advanced DIYers who frequently work with stainless steel, hardened alloys, and other difficult-to-drill metals, seeking professional-grade bits that offer durability and performance without compromising budget.
Pros and Cons
Pros:
- M42 Cobalt (8% content) offers exceptional heat resistance and an extended lifespan.
- Three-flat shank design effectively prevents slippage, enhancing drilling safety and precision.
- Excellent performance for drilling tough materials like stainless steel and other alloys.
- Reputable Bosch quality at a competitive price point for genuine cobalt bits.
Cons:
- Smaller set size (14 pieces) compared to some other options, limiting range.
- Cobalt bits can be more brittle than HSS if subjected to excessive side pressure or mishandling.
Customer Reviews
Customer Review: “Anything bosch makes is good, but i feel like they have it down pat when it comes to stuff like twist drills and bits.The M42 cobalt keeps the drill from getting too hot and also acts as a “lubricant”, both contributing to keeping a sharp cutting edge, giving it quality and ease of use.These factors” – Amazon Customer
Customer Review: “This is a great drill bit set. The reason I purchased this set is because I needed to drill and tap a hole in the end of a lawnmower engine crankshaft. Rather than buying just that drill bit I decided to get a whole set, because I knew I would need drill bits again. I decided to go with this set ove” – Jeffrey J. White
4. HSS 29-Piece Drill Bit Set, 1/16-1/2″ with 135° Split Point for Hard Steel
The HSS 29-Piece Drill Bit Set offers a comprehensive range of sizes from 1/16″ to 1/2″, making it a versatile choice for various drilling tasks, especially in hard steel. Designed with a 135° split point, these bits ensure fast, accurate starts and superior performance, with claims of outperforming some cobalt drills in terms of flexibility and speed.
Key Features That Stand Out
- ✓ 135° Split Point Tip: Allows for fast, accurate drilling and effectively prevents bit walking without the need for pre-drilling.
- ✓ Tapered Web Geometry: Provides added strength and rigidity to the bit, minimizing breakage and extending its overall lifespan.
- ✓ Flatted Shanks: Ensures secure gripping in keyless power tool chucks, significantly reducing slippage during heavy-duty drilling operations.
- ✓ Enhanced Durability: Claims to drill 3x longer and 2x faster than competitors, designed to be more flexible and less prone to chipping than some cobalt drills.
Why We Recommend It
This HSS set stands out for its impressive claims of extended life and faster drilling, combined with features like the split point and flatted shanks that enhance user experience and performance on tough metals. It offers a large, versatile collection suitable for a wide range of tasks.
Best For
Individuals needing a large, versatile set of durable bits for general metalworking, automotive repairs, and construction, particularly when drilling into a variety of hard steels where flexibility, robust performance, and a comprehensive size range are valued.
Pros and Cons
Pros:
- Comprehensive 29-piece set covers a wide range of common drilling sizes.
- 135° Split Point ensures quick, precise starts and prevents bit walking.
- Flatted shanks provide excellent chuck grip, reducing slippage and improving safety.
- Designed for impressive durability and resistance to chipping, with enhanced flexibility over some cobalt options.
Cons:
- May still heat up faster than pure cobalt bits in extremely heavy-duty, continuous applications.
- “Better than cobalt” claims can vary significantly based on specific usage, material hardness, and drilling technique.
Customer Reviews
Customer Review: “I’ve drilled a bazillion holes in every kind of material you can think of over more than 65 years of being an automotive technician, and used up my share of drill bits. I’ve learned to recognize good ones from bad ones and I’d have to say that these appear to be among the best quality around. Beauti” – Amazon Customer
Customer Review: “These bits truly live up to their claims. I’ve been working on a custom metal fabrication project, and these HSS bits have consistently outperformed other brands I’ve tried. The split point makes a huge difference, especially on stainless steel, no more skating around.” – David K.
5. M35 Cobalt Drill Bit Set for Hard Steel and Stainless Steel, 1/16″-3/8″ Range
This M35 Cobalt Drill Bit Set is a high-performance choice specifically engineered for effectively drilling through hard steel and stainless steel. With bits ranging from 1/16″ to 3/8″, this set features premium M35 Cobalt material, known for its superior hardness and extended lifespan compared to conventional drill bits, offering exceptional quality and performance.
Key Features That Stand Out
- ✓ M35 Cobalt Material: Features a high cobalt content, offering exceptional hardness (up to 67 HRC) and resistance to abrasion and high temperatures.
- ✓ Hardened Full Grinding Process: Increases wear resistance, maintains sharpness, and enhances overall durability, ensuring clean and efficient cuts.
- ✓ Extended Lifespan: Designed to cut faster and last up to 12 times longer than average HSS titanium-coated bits, providing long-term value.
- ✓ Versatile Application: Suitable for a wide range of tough metals including stainless steel, cast iron, zinc alloy, titanium, and aluminum.
- ✓ Organized Packaging: Comes in a hard, thick plastic box with individually bagged drills for compartmentalized, secure storage and easy access.
Why We Recommend It
The M35 cobalt composition and full grinding process make these bits incredibly effective for the most challenging drilling tasks. They offer superior cutting speed and remarkable longevity, making them a wise investment for repetitive work on hardened materials where consistent performance is critical.
Best For
Fabricators, industrial users, machinists, and serious hobbyists who regularly drill into extremely hard materials such as stainless steel, cast iron, and exotic alloys, prioritizing maximum durability, cutting efficiency, and bit lifespan.
Pros and Cons
Pros:
- M35 Cobalt offers superior hardness and an incredibly long lifespan (up to 12x HSS TiN).
- Full grinding process ensures optimal sharpness, precision, and extended durability.
- Excellent performance for very tough materials like stainless steel and titanium.
- Organized and protective packaging for easy storage and bit protection.
Cons:
- Higher price point compared to HSS or basic TiN-coated drill bits.
- Can be more susceptible to breakage if subjected to excessive side pressure or improper drilling angles.
Customer Reviews
Customer Review: “Good quality bits even though from offshore. Stay sharp for a long time.” – Amazon Customer
Customer Review: “Had a lug nut stripped. Only way off was to drill lug bolt. These bit eight right through it.” – Amazon Customer
Complete Buying Guide for Best Drill Bits For Hard Steel
Essential Factors We Consider
When selecting the best drill bits for hard steel, several critical factors must be taken into account to ensure efficiency, durability, and safety. The primary consideration is the bit material; cobalt drill bits (M35 or M42 alloys) are paramount for their high heat resistance and hardness, which are crucial when drilling tough metals like hardened steel or stainless steel. High-Speed Steel (HSS) with specialized coatings like Titanium Nitride (TiN) or Titanium Aluminum Nitride (TiAlN) also offers enhanced performance over uncoated HSS.
Another vital aspect is the tip geometry. A 135° split point is highly recommended as it prevents “walking” on the workpiece, allows for faster starts, and requires less thrust force, leading to cleaner and more accurate holes. The shank type (e.g., three-flat shanks) impacts how securely the bit grips in the drill chuck, preventing slippage. Finally, consider the set size and range to ensure you have the appropriate diameters for your typical projects, and always factor in the brand’s reputation for quality and consistency.
Budget Planning
Investing in quality drill bits for hard steel is crucial, but it doesn’t always mean breaking the bank. There’s a direct correlation between bit material, coatings, and price. While standard HSS bits are the most affordable, they won’t hold up to hard steel. Titanium Nitride (TiN) coated HSS bits offer a good balance of performance and cost, providing improved durability. For the ultimate performance and lifespan in the toughest materials, cobalt drill bits (M35 or M42) are the top choice, albeit with a higher initial investment. However, their superior longevity and efficiency often make them more cost-effective in the long run, reducing the need for frequent replacements. Plan your budget based on the frequency and intensity of your drilling tasks into hard metals, prioritizing quality for demanding applications.
Final Thoughts
Choosing the right drill bit is more than just picking a size; it’s about matching the tool to the task. For hard steel, sacrificing quality for a lower price will only lead to frustration, dull bits, and potential project delays. Always opt for cobalt drill bits or high-quality HSS with advanced coatings like TiN or TiAlN, combined with a 135° split point. Proper technique—using appropriate speed, consistent pressure, and plenty of cutting fluid—will maximize the life and performance of even the best drill bits. By considering these factors, you can equip yourself with the tools to tackle any challenging metal drilling project with confidence and precision.
Frequently Asked Questions
Q: What makes a drill bit suitable for hard steel?
A: Drill bits suitable for hard steel typically feature materials like cobalt (M35 or M42) or high-quality High-Speed Steel (HSS) with specialized coatings such as Titanium Nitride (TiN) or Titanium Aluminum Nitride (TiAlN). A 135° split point tip is also crucial for preventing walking and initiating cuts effectively and efficiently.
Q: Cobalt vs. Titanium Nitride (TiN) coated HSS bits – which is better for hard steel?
A: For truly hardened steel and continuous heavy-duty use, cobalt drill bits (M35 or M42) are generally superior due to their inherent heat resistance and hardness throughout the material. TiN-coated HSS bits are excellent for general-purpose drilling in hard metals and offer good durability, but their coating is only on the surface, which can wear off, while cobalt’s properties are consistent throughout.
Q: Do I need to use lubricant when drilling hard steel?
A: Yes, absolutely. Using a cutting fluid or lubricant is highly recommended when drilling hard steel. It helps to reduce friction, dissipate heat, prevent bit overheating, extend the life of the drill bit, and achieve cleaner, more precise cuts.
Q: What drill speed should I use for drilling hard steel?
A: When drilling hard steel, it’s crucial to use a lower RPM (revolutions per minute) compared to drilling softer materials. High speeds generate excessive heat, which can quickly dull or destroy the drill bit. Always refer to the manufacturer’s recommendations or use a drill speed chart for specific material and bit sizes.
Q: Why do my drill bits keep breaking when drilling hard steel?
A: Common reasons for drill bits breaking when drilling hard steel include using the wrong type of bit (not suitable for hard metals), excessive pressure, insufficient lubrication, too high a drill speed causing overheating, or improper workpiece clamping leading to bit wobble and bending. Ensure you’re using a quality cobalt drill bit, appropriate speed and pressure, and plenty of cutting fluid.
Choosing the right drill bits for your projects involving hard steel can make all the difference in terms of efficiency, bit longevity, and the quality of your work. We hope this comprehensive guide has helped you understand the critical factors and top products available. By investing in one of our recommended best drill bits for hard steel, you’ll be well-equipped to tackle even the toughest drilling challenges with confidence. Don’t let hard metals stand in your way – upgrade your toolkit today!
I’m Darrell Julian, the founder, lead writer, and hands-on welding enthusiast behind ArcWeldingPro.com. With more than 15 years of real-world welding experience, I created this platform to share what I’ve learned in the field, in the shop, and in the heat of the arc.
