The Best Drill Bits for Drilling Out Stubborn Bolts: Your Ultimate Guide

We’ve all been there. You’re working on a project, maybe restoring a classic car, fixing a piece of machinery, or even just assembling some IKEA furniture, and you encounter *that* bolt. It’s seized, rusted, stripped, or just plain stubborn. Trying to force it with a wrench is a futile exercise, and you’re left with a frustrating roadblock. The solution? Drilling it out. But not just any drill bit will do. Choosing the right drill bit for this often-delicate operation is crucial to avoid further damage, wasted time, and unnecessary expense.

Drilling out a bolt requires precision, the right materials, and, most importantly, the right tools. The wrong drill bit can shatter, bend, or simply fail to penetrate the hardened steel of a stubborn fastener, leaving you with an even bigger mess. This guide is designed to equip you with the knowledge to select the absolute best drill bits for tackling those challenging bolt removal jobs. We’ll delve into what makes a drill bit ideal for this task, highlight key features to consider, and then dive into our top 5 Amazon recommendations, complete with reviews, pros, cons, and expert tips.

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Product Reviews: The Top Picks for Drilling Out Bolts

When you’re faced with a bolt that just won’t budge, the right drill bit can be the difference between a successful repair and a frustrating failure. We’ve scoured Amazon and consulted with DIY enthusiasts and professionals to bring you the best drill bits designed specifically for the challenging task of drilling out stubborn bolts. These selections prioritize durability, precision, and effectiveness.

1. DEWALT Titanium Nitride Coated High-Speed Steel Twist Drill Bit Set

2. CO-Z Broken Screw Extractor Set

3. IRWIN HANSON Bolt-Out Bolt and Screw Extractor Set

4. Neiko 10057A Titanium Coated High-Speed Steel Drill Bit Set

5. VAMPLIERS Screw Extractor Pliers (VT-001-S)

Who Should (and Shouldn’t) Buy Drill Bits for Drilling Out Bolts?

You should definitely consider investing in a quality set of drill bits specifically for drilling out bolts if:

• You’re a DIY enthusiast who enjoys restoring cars, motorcycles, or other mechanical equipment.
• You frequently encounter stubborn, rusted, or stripped bolts in your projects.
• You want to avoid damaging the surrounding material when removing a damaged fastener.
• You’re looking for a reliable solution to a common mechanical problem.
• You value precision and efficiency in your repairs.

Conversely, you might not need a specialized set if:

• You only perform very light-duty tasks around the house and rarely encounter seized fasteners.
• Your projects primarily involve wood or softer materials where standard drill bits suffice.
• You have access to a professional mechanic or workshop that handles all challenging fastener removals.
• You’re not comfortable using power tools or performing mechanical repairs.

Real Customer Experiences

We’ve sifted through countless customer reviews on Amazon to give you a real-world perspective on using these drill bits for bolt extraction. Here’s a summary of what actual users are saying:

Expert Tips / Pro Insights

To get the most out of your drill bits when removing bolts, consider these professional tips:

• Center Punch First: Always use a center punch to create a small indentation at the exact center of the bolt you intend to drill. This prevents the drill bit from “walking” and ensures a clean, straight hole.
• Start Small: Begin with a smaller drill bit (e.g., 1/8 inch) to create a pilot hole. This makes it easier for larger bits to follow and reduces the risk of the bolt breaking or the bit wandering.
• Lubricate: Use a cutting fluid or lubricant (like WD-40, cutting oil, or even a bit of bar soap) on the drill bit and the bolt. This reduces friction, cools the bit, and helps clear away metal shavings, extending the life of your drill bit and making drilling smoother.
• Variable Speed Control: Use a drill with variable speed settings. For drilling into metal, slower speeds are generally better to prevent overheating and bit damage.
• Apply Steady Pressure: Don’t force the drill. Apply consistent, steady pressure. Let the sharpness of the bit do the work.
• Drill Straight: Maintain a perpendicular angle between the drill bit and the bolt head. Drilling at an angle can cause the bit to bind or break.
• Consider an Extractor: Once you’ve drilled a pilot hole, a screw or bolt extractor (like the IRWIN Bolt-Out or CO-Z set) is often the next step. Tap the extractor gently into the pilot hole and then use a wrench or drill (in reverse) to unscrew the bolt.
• Peen the Bolt Head: For very stubborn bolts, some mechanics suggest peening (hammering) the bolt head lightly with a hammer and punch. This can sometimes break the rust bond.

Step-by-Step Buying Decision Flow

Choosing the right drill bits for bolt extraction can feel overwhelming, but following this simple flow can help you make the best decision:

• Assess the Problem: Is the bolt rusted, stripped, or just seized? Is the head intact, rounded, or completely gone?
• Consider Bolt Material: Most bolts are hardened steel. Ensure your drill bits are rated for metal drilling.
• Determine Bolt Size: What is the diameter of the bolt you need to remove? This will dictate the range of drill bit sizes you require.
• Evaluate Your Needs: How often will you be performing this task? For occasional use, a good general-purpose set might suffice. For frequent use, invest in higher-quality, specialized bits.
• Prioritize Bit Material: High-Speed Steel (HSS) is standard. For extra durability and heat resistance, look for Titanium Nitride (TiN) or Cobalt coatings.
• Look for Key Features:
  • Split Point Tip (135°): Essential for preventing bit walk and ensuring accurate starting on metal.
  • Self-Tapping/Reverse Flutes: Crucial for screw/bolt extractors to grip the damaged fastener.
  • Double-Ended Design: Convenient for integrated drilling and extraction.
• Check the Set Contents: Does the set include a sufficient range of sizes for common bolt diameters? Is there a case for storage?
• Read Reviews: See what other users have experienced with specific sets, paying attention to durability and performance on tough materials.
• Consider Specialized Tools: If bolt heads are frequently rounded, think about including pliers like VAMPLIERS in your arsenal.
• Budget Wisely: While cheaper bits might seem appealing, they often wear out quickly or break, costing more in the long run. Invest in quality for reliability.

Buying Guide: What to Look For

When you’re on the hunt for the best drill bits to tackle those stubborn bolts, keep these key factors in mind:

Material is King: High-Speed Steel (HSS) and Beyond

At a minimum, you want drill bits made from High-Speed Steel (HSS). HSS offers a good balance of hardness and toughness, allowing it to withstand the heat generated during drilling into metal. For even better performance, especially when dealing with hardened bolts, look for bits with coatings:

• Titanium Nitride (TiN) Coating: This is a very common and effective coating. It adds a layer of hardness, reduces friction, and increases resistance to heat, significantly extending the bit’s lifespan and allowing for faster drilling.
• Cobalt: Cobalt alloyed HSS bits are even harder and more heat-resistant than TiN-coated bits. They are ideal for drilling into very hard metals like stainless steel or hardened tool steel, but they can be more brittle, so they require careful handling.

The Power of the Tip: Split Points and More

The tip geometry of a drill bit plays a crucial role, especially when drilling metal:

• 135-Degree Split Point: This is the gold standard for drilling metal. The split point tip is self-centering, meaning it won’t “walk” or wander when you start drilling. This allows for precise placement, which is critical when you need to drill directly into the center of a bolt to weaken it or prepare it for an extractor. Standard 118-degree points are better suited for softer materials.
• Self-Tapping Threads (for Extractors): If you’re looking at combined drill bit/extractor sets, ensure the extractor end has aggressive, self-tapping threads designed to bite into the metal of the pilot hole.

Durability and Design

Beyond the material and tip, consider:

• Flute Design: The flutes carry away chips. For bolt extraction, you want efficient chip clearance to prevent the bit from overheating or binding.
• Overall Build Quality: Look for bits that feel solid and well-made. Check for consistent grind and finish.
• Set Contents: A good set will offer a range of common sizes, typically from 1/16 inch up to 1/2 inch, to accommodate various bolt diameters.

Specialized Tools: Extractors and Pliers

While drill bits are essential for preparing the bolt, specialized extractors and pliers can be invaluable:

• Screw/Bolt Extractors: These are designed to grip the inside of a drilled hole and unscrew the damaged fastener. They often feature reverse spiral flutes.
• Extractor Pliers: Tools like VAMPLIERS are excellent for gripping rounded bolt heads that have lost their original shape, providing a strong mechanical grip.

Common Mistakes to Avoid

• Using Dull Bits: Dull bits generate more heat, require more force, and produce poor results. Keep your bits sharp.
• Drilling Too Fast: Excessive speed leads to overheating, dulling the bit and potentially hardening the metal further. Use slower speeds for metal.
• Not Using Lubricant: Cutting fluid or oil is essential for drilling metal. It cools the bit, reduces friction, and helps clear chips.
• Drilling Off-Center: This makes it difficult to use extractors and can damage the surrounding material. Always use a center punch.
• Using the Wrong Bit for the Job: Wood bits or masonry bits will not perform well on metal and will likely be damaged.
• Applying Too Much Pressure: Let the bit do the work. Forcing it can cause it to break or the workpiece to be damaged.

Tips for Maintaining Your Drill Bits

• Clean After Use: Remove metal shavings and debris from the flutes after each use.
• Store Properly: Keep bits in their original case or a dedicated bit organizer to prevent damage and loss.
• Keep Them Dry: Prevent rust by storing bits in a dry environment.
• Sharpen When Necessary: While coatings help, even the best bits will eventually dull. Learn to sharpen them or replace them when needed.

“Before You Buy” Checklist

• Is the bit made of High-Speed Steel (HSS)?
• Does it have a Titanium Nitride (TiN) or Cobalt coating for durability?
• Does it feature a 135-degree split point tip for metal drilling?
• Does the set include a range of sizes appropriate for common bolts?
• Are there any specialized extractor bits or tools included if needed?
• Are customer reviews generally positive regarding performance on metal?
• Is the storage case durable and organized?
• Does the price align with your budget and the quality offered?

Internal & External Linking Strategy

To further enhance your understanding and skills, consider these resources:

Internal Links:

• For other common workshop challenges, check out our guide on the best impact drivers for automotive work.
• Learn how to keep your tools in top shape with our tips on the best tool sharpeners.

External Links:

• For a deeper dive into metalworking techniques, consult Popular Mechanics’ how-to section.
• Understand the properties of different metals and drill bits by visiting Manufacturing.net.

Frequently Asked Questions (FAQ)

Q1: What is the best type of drill bit for removing a seized bolt?

A1: For seized bolts, you generally want a high-quality High-Speed Steel (HSS) drill bit, preferably with a Titanium Nitride (TiN) or Cobalt coating for added hardness and heat resistance. A 135-degree split point tip is also highly recommended to prevent the bit from wandering and ensure accurate drilling into the center of the bolt.

Q2: Can I use a regular drill bit to drill out a bolt?

A2: While you *can* attempt it with standard HSS bits, they will dull very quickly and may even break when drilling into hardened bolt material. Specialized bits designed for metal, especially those with coatings and split points, will provide much better results and longevity.

Q3: What size drill bit should I use to drill out a bolt?

A3: The size of the drill bit depends on the size of the bolt and whether you intend to drill it out completely or just enough to use a screw extractor. Typically, you’ll start with a smaller pilot bit (e.g., 1/8″ or 3/16″) and gradually increase the size until you reach a diameter that is slightly smaller than the bolt’s shank. If using an extractor, follow the extractor manufacturer’s recommendation for pilot hole size. For complete removal, you’ll drill out the entire core of the bolt.

Q4: How do I prevent the drill bit from walking when starting a hole in a bolt?

A4: The best way to prevent bit walk is to use a center punch to create a small indentation at the exact spot where you want to drill. This gives the tip of the drill bit a place to seat itself. Additionally, using a drill bit with a 135-degree split point tip is highly effective at preventing wandering.

Q5: Is it better to use a drill or an impact driver to drill out a bolt?

A5: For drilling out bolts, a standard drill (preferably with variable speed and torque control) is generally better than an impact driver. Impact drivers deliver rapid rotational impacts, which can cause the drill bit to break or create an oversized, irregular hole, especially when drilling into metal. A drill allows for more controlled speed and pressure.

Q6: What is a bolt extractor, and how does it work?

A6: A bolt extractor, also known as a screw extractor or Easy Out, is a tool designed to remove broken or stubborn screws and bolts. After drilling a pilot hole into the damaged fastener, the extractor is inserted. It typically has reverse spiral flutes that bite into the metal of the pilot hole as you turn the extractor counter-clockwise, gripping the bolt and allowing you to unscrew it.

Q7: How do I keep my drill bits cool while drilling metal?

A7: Keeping drill bits cool is crucial for their longevity and performance. Use a cutting fluid, cutting oil, or even a light machine oil. Apply it to the drill bit and the workpiece regularly as you drill. Also, periodically withdraw the drill bit from the hole to allow chips to clear and the bit to cool down. Avoid excessive speed, as this generates more heat.

Conclusion

Tackling seized or stripped bolts is a common challenge for anyone working with machinery, vehicles, or even household repairs. The right drill bits can transform a potentially frustrating ordeal into a manageable task. We’ve highlighted the importance of **High-Speed Steel (HSS)**, beneficial coatings like **Titanium Nitride (TiN)**, and the precision offered by **135-degree split point tips**.

Our top picks, from the versatile DEWALT Titanium Nitride Coated HSS Twist Drill Bit Set for overall performance to the specialized IRWIN HANSON Bolt-Out Bolt and Screw Extractor Set for tough jobs, offer solutions for various needs and budgets. Remember to always prioritize safety, use appropriate lubricants, and employ a steady hand for the best results.

Don’t let a stubborn bolt be the end of your project. Equip yourself with the right tools and knowledge. Click on the Amazon links above to explore these highly-rated drill bits and extractor sets, and get back to what you do best!