Choosing the right cobalt drill bits for stainless steel relies on durability, heat tolerance, and chuck compatibility. The five featured sets below cover a range of cobalt contents, lengths, and shank styles, offering reliable performance on stainless and other hard metals. Whether you’re drilling automotive parts, appliances, or metalwork projects, these options balance cutting speed with long life. Review the key features and how each set fits your tooling needs before making a purchase.
| Product | Brand | Key Benefit | Cobalt Content |
|---|---|---|---|
| BOSCH CO14B 14-Piece Set | Bosch | Durable M42 bits with three-flat shank and included case | 8% |
| NordWolf M35 Stubby 5-Piece | NordWolf | Compact reach with self-centering tips for stainless steel | 5% |
| STROTON M42 19-Piece Set | STROTON | Wide size range and robust three-step design for tough metals | 8% |
| toolant 21-Piece Pro Cobalt | toolant | TiAlN coating with bullet-point tips for metal drilling | 5% |
| Bestwork 21-Piece Cobalt | Bestwork | Three-flute design with secure three-flat shank | 5% |
Bosch Co14B Cobalt Drill Bit Set
The Bosch CO14B set uses Cobalt M42 alloy for enhanced durability and heat resistance, with an 8% cobalt composition designed for stainless steel, cast iron, titanium, and light-gauge metals. The bits are jobber-length and feature a three-flat shank for a secure grip in higher-torque chucks, making them suitable for metalworking tasks where precision and longevity matter. An included case helps keep the assortment organized between jobs, supporting quick access and protection during storage.
- Cobalt M42 with 8% cobalt for durability
- Jobber-length bits with three-flat shank for grip
- High-heat resistance for stainless steel and hardened surfaces
- Includes protective carrying case
Designed to drill through stainless steel, cast iron, titanium, and other hard metals, these bits aim to balance cutting speed with long tool life. When working with stainless, use steady feeds and appropriate lubrication to manage heat buildup and extend bit life.
NordWolf M35 Cobalt Stubby Drill Bits
The NordWolf set uses M35 cobalt steel with precision-ground bits for durability and a long service life. Stubby lengths (ranging from 1.84 to 2.32 inches) provide access to tight spaces where standard-length bits won’t reach. A 135° split point combined with multi-blade tips promotes self-centering and faster drilling, reducing walking and improving accuracy. The 1/4-inch hex shank is compatible with standard and quick-change chucks and drivers, making these bits versatile for metalworking tasks that require maneuverability in confined areas.
- M35 cobalt steel for enhanced wear resistance
- Stubby length (1.84″–2.32″) for tight spaces
- 135° split point with multi-blade tips for self-centering
- 1/4″ hex shank for quick-change compatibility
Best used on stainless steel and other hardened metals such as cast iron and titanium. For best results, apply steady pressure, avoid overheating, and use lubrication as needed to extend tool life in demanding drilling tasks.
STROTON M42 19-Piece Cobalt Set
STROTON’s 19-piece M42 cobalt set emphasizes high heat and wear resistance with 8% cobalt content. The bits feature a rugged 68-70 HRC hardness range to withstand the stresses of drilling through stainless steel and other hard metals. A 3-step design supports efficient cutting through tough materials with improved heat management. While the price per hole is often lower due to higher overall lifespan, users can expect longer intervals between blade replacements when drilling stainless steel and similar metals.
- Premium M42 8% cobalt steel for durability
- 68–70 HRC hardness for heat resistance
- 3-step cutting design for efficient metal drilling
- Wide size range in a single set
For best performance, maintain moderate speeds and use cutting fluid or lubrication to minimize heat buildup. This set is well-suited for stainless steel, hardened metals, aluminum, and other challenging materials, offering a balance of speed and longevity across a broad range of sizes.
Toolant Cobalt Drill Bit Set Pro
The Toolant Pro set comprises 21 titanium aluminum nitride (TiAlN) coated cobalt drill bits with bullet-point tips, designed to cut through metal with minimal heat buildup. The range spans 1/16″ to 1/2″ in a compact kit, including multiple copies of smaller sizes. TiAlN coating increases surface hardness to about 89 HRC, aiding faster cuts and sharper edges for longer periods. The bullet-point tips further enhance starting accuracy and reduce walking on tough metals like stainless steel and cast iron.
- 21-piece cobalt set with TiAlN coating
- Bullet-point tips for precise starts
- Sizes include 1/16″ to 1/2″ with duplicates for small steps
- High hardness coating for extended life
These bits are suitable for drilling through hardened metals and stainless steel with reliable performance in both hand-held drills and drill presses. Proper lubrication and moderate feed rates help maintain tool life when working on demanding metalwork projects.
Bestwork 21-Piece Cobalt Drill Bit Set
Bestwork’s Three-Flute Cobalt Drill Bit Set uses 5% cobalt steel (M35) and emphasizes a three-flute design to improve chip removal and heat dissipation. The three-flat shank helps prevent slipping in the chuck, enabling steadier performance under load. A split-point tip reduces walking at the start of a cut, which is valuable when drilling through hard metals like stainless steel. The 21-piece assortment covers a broad range of common drill sizes, reducing the need to swap bits mid-project.
- Three-flute design for smoother walls and better chip removal
- M35 cobalt steel with 5% cobalt content
- Three-flat shank prevents slipping in the chuck
- 135-degree split point for precise starts
When drilling stainless steel, maintain steady speeds, use appropriate lubrication, and avoid excessive feed pressure to maximize tool life. The kit’s variety makes it a practical choice for home shops and light industrial work that requires quick access to a wide size range of cobalt bits.
Buying Guide
- Material compatibility: Choose cobalt bits specifically rated for stainless steel and hardened metals. M35 (5%) and M42 (8%) cobalt content inform wear resistance and life in tough materials.
- Cobalt content: Higher cobalt (M42) generally offers improved heat resistance and longer life in stainless steel, but may come at a higher price. Consider your typical material and budget.
- Shank design: Round shanks are standard, while three-flat or hex shanks improve grip in chucks and quick-change systems. For quick-changes, ensure compatibility with your drill chuck type.
- Length and reach: Stubby bits suit tight spaces; jobber-length bits cover more depth and general drilling. Select length based on access to workpieces and clearance in your drilling setup.
- Tip geometry and flute design: Split-point tips reduce wandering at start; three-flute designs improve chip removal and heat dissipation, which matters for stainless steel drilling.
- Coatings: TiAlN and similar coatings can raise surface hardness and heat resistance, extending bit life in metal applications.
- Set size and range: Larger sets offer size variety but may be heavier and pricier. Consider common diameters you encounter most often and whether you need duplicates of frequently used sizes.
- Packaging and organization: A robust case helps keep bits organized and protected, reducing loss and damage between tasks.
- Drilling strategy: Use cutting fluid or lubrication, moderate speeds, and proper feed rates to minimize heat buildup and prolong tool life when drilling stainless steel.
- Maintenance: Clean and dry bits after use; avoid exposing cobalt bits to corrosive environments that could degrade coating or the steel alloy.