How to Remove a Broken Drill Bit from a Screw: Advanced Techniques and Tools

Dealing with a broken drill bit caught in a screw can be frustrating. However, with the right tools and techniques, you can successfully extract the broken part and restore your project. This guide will explore various methods including the use of screw extractors, pliers, penetrating oil, and specialized tools like Dremels. By the end, you will be equipped with the knowledge and tools necessary to repair these broken tools and materials.

Understanding the Problem

The issue of a broken drill bit often arises from improper usage. Factors such as using a small drill bit, over-tightening the drill, or encountering a hardened material like an 8 mm allen bolt can cause the bit to break. In these cases, traditional screw extractors or broken screw removers may not be effective. This guide will demonstrate advanced methods that can handle even the most stubborn broken drill bits.

Step-by-Step Guide for Removal

Screw Extractors and Penetrating Oil

One of the first steps in dealing with a broken drill bit is to apply penetrating oil around the broken part. Penetrating oil, such as WD-40, can help loosen the stuck bit and make it easier to extract. However, if this method fails, here are some alternative techniques:

Screw Extractor: Screw extractors are designed to create a slot in the broken bit, making it possible to remove it using a screwdriver. Ensure you have the correct size extractor to match the bit.Pliers: In some cases, you can use locking pliers or a vice grip to apply pressure and extract the broken bit. This method requires a bit of force and dexterity.

Advanced Techniques

For more challenging situations, you may need to employ advanced techniques and specialized tools:

Dremel with Diamond Impregnated Disc: A Dremel tool with a diamond disc can create a slot in the top of the broken screw, allowing you to use a flat blade screwdriver to remove it. This method is particularly useful if the screw is flush with the surface.Spark Erosion: In valuable or critical applications, spark erosion can be a solution. This process uses a portable machine with a spark erosion tool to remove the broken screw. While this method is more expensive (around $3000), it is invaluable for precision and valuable parts.

Handling Hardened Materials

In some scenarios, the broken drill bit is a hardened material, such as an 8 mm allen bolt. Traditional methods may not be effective, requiring specialized tools like a diamond bit in a Dremel or a specialty grinder. Here’s how to tackle this issue:

Using a Diamond Bit: A diamond bit can grind out the center of the broken screw. Obtain a cheap 20-pack of such bits from stores like Harbor Freight. The process may take several minutes, but it is often the most reliable method.Tapping the Hole: After removing the broken part, use a tap to clean and secure the hole. This step helps ensure the integrity of the screw or bolt.

Conclusion

Facing a broken drill bit in a screw can be frustrating, but with the right tools and techniques, you can repair the damage and continue your project. Whether you use screw extractors, pliers, a Dremel, or advanced methods like spark erosion, you can successfully extract the broken bit. Regular maintenance and proper drilling techniques can also help prevent this issue from arising in the future.

Additional Resources

For more tips on dealing with broken tools and DIY repair advice, check out my Quora profile. If you have any specific questions or need further assistance, feel free to reach out for guidance.