Answering the top search need for buyers: these heavy steel drill bits are designed to cut through tough metals like stainless steel, cast iron, and aluminum, as well as plastics and wood for versatile use. The featured selections cover cobalt, carbide, and high-quality HSS options, offering options for professionals and DIYers alike. The best fits include sets for broad needs, and individual bits for precision work. The quick comparison below helps identify who benefits most from each option.
| Product | Best For | Notes |
|---|---|---|
| 7/8 Inch Cobalt Drill Bit, M35 HSS Twist Drill Bit | Heavy metal fabrication | 135° split point; robust for hard metals |
| Shars #1-#60 M35 Cobalt Jobber Drill Set | Comprehensive metalworking | 60-piece cobalt set for varied needs |
| 29Pcs(1/16″-1/2″) Cobalt Drill Bit Set M35 HSS | Versatile home shop | Wide range; fast cutting with 135° tip |
| LU&MN Solid Carbide Jobber Drill Bit | Precision small-diameter work | Carbide for stainless and tough materials |
| DEWALT Drill Bit Set, 14-Piece, 135 Degree Split Point | General purpose metal/plastic/wood | Known brand with durable HSS and split point |
7/8 Inch Cobalt Drill Bit
Best for high-hardness metals and demanding tasks, the 7/8 inch cobalt bit delivers boosted wear resistance and rapid cutting in stainless and alloy steels. The 135° split point helps start accurately and reduces walking on tough materials. Choose this if you frequently work with hard metals and need an extended tool life in harsh environments. Caution: Bits are robust but can be brittle under significant lateral stress; use proper clamping.
Shars Cobalt Set
Best for metalworkers needing a broad bit collection. The 60-piece cobalt set provides a wide size range for milling, drilling stainless and hard alloys, and miscellaneous metals. Best for workshops that require quick access to various sizes. Caution: heftier sets require organized storage to prevent loss of small bits.
29Pcs Cobalt Drill Bit Set M35 HSS
Best for multi-size projects in a home shop, this 29-piece set spans from 1/16″ to 1/2″ with M35 cobalt. The 135° point and twist design aim for faster cutting and self-centering to reduce walk-off. It’s a strong choice for stainless steel and soft metals as well as plastics. Caution: set may include smaller bits that wear quickly if used on harder metals without proper feed and speed.
LU&MN Solid Carbide Bit
Best for small, precise work and high wear resistance in stainless and alloys. Carbide bits offer enhanced hardness and longer life in demanding materials, making them ideal for precision drilling in metal fabrication. Best for machinists and model makers. Caution: carbide bits are brittle under heavy side loads; clamp securely and avoid lateral pressure.
DEWALT Drill Bit Set, 14-Piece
Best for general purpose use across plastic, wood, and metal. The set features 135-degree split-point tips to reduce walking and improve start accuracy. High-speed steel construction supports versatile applications, with a tapered web design for durability. Choose this for a reliable, all-around option from a trusted brand. Caution: not all sizes are ideal for extremely hard metals; use appropriate speeds and feeds.
Buying Guide
- Metal type: For stainless steel and hard alloys, cobalt (M35) and carbide offer superior wear resistance. For softer metals and mixed materials, high-speed steel (HSS) is often sufficient.
- Point angle and geometry: 135-degree split points help start accurately and reduce walking. Self-centering designs improve chip removal and reduce wandering.
- Set vs. individual bits: Sets provide size variety for a wide range of tasks, while individual bits are ideal for replacement or specialty work.
- Diameter range: Consider the largest and smallest sizes you need; 1/16″ to 1/2″ is common in cobalt sets, while larger bits suit heavy fabrication.
- Shank and compatibility: Ensure shank type fits your drill chuck and tool holders. Some sets use standard 1/4″ shanks for broad compatibility.
- Durability vs cost: Carbide bits last longer in tough materials but are more brittle; cobalt bits offer a balance of durability and toughness for hard metals.
- Storage and organization: Larger sets require proper storage to prevent loss of small-diameter bits and to keep your workspace organized.
Frequently Asked Questions
- What is the main difference between cobalt and carbide drill bits?
Co-balt bits (M35) are made from cobalt alloys and offer excellent wear resistance for hard metals with some toughness. Carbide bits are harder and stay sharp longer but can be more brittle under lateral load.
- When should I choose a 135-degree split point?
A 135-degree split point improves starting accuracy and reduces walking on hard materials, making it ideal for stainless steel and tougher alloys.
- Are sets better than individual bits for beginners?
Yes, sets provide a range of sizes for various tasks, helping new users tackle multiple projects without buying many separate bits.
- Can cobalt bits drill through wood and plastic effectively?
Yes, cobalt bits perform well on soft metals and can drill plastics and wood, though for wood you might prefer a brad point or spade bit for cleaner holes in some cases.
- How do I prevent bit wear when drilling hard metals?
Use proper lubrication, avoid excessive feed pressure, and maintain correct speeds. Secure the workpiece and use a sharp bit designed for the material.