How to Drill Out a Bolt: Effective Techniques

How to Drill Out a Bolt?

To drill out a bolt, you will need a center punch, a drill, and a bolt extractor.

Begin by center-punching the broken bolt to mark the pilot hole.

Then, using a small drill bit, create a pilot hole in the center of the broken bolt.

Gradually increase the size of the drill bit, gradually boring out the bolt extraction hole until there is very little bolt shank left.

Next, use a bolt extractor, a left-handed thread tool, to screw into the bolt shank and remove it.

Be careful not to break the extractor off in the bolt shank.

If the bolt is stuck due to corrosion, success may be low, but if it sheared off due to material failure, there’s a better chance of removing it.

After removing the bolt, clean the threads with a thread chaser or thread cleaner.

If the threads are badly damaged, a Heli-Coil threaded insert can be used for thread replacement.

Key Points:

  • Gather the necessary tools: center punch, drill, and bolt extractor
  • Start by center-punching the broken bolt to mark the pilot hole
  • Create a pilot hole in the center of the broken bolt using a small drill bit
  • Gradually increase the size of the drill bit to bore out the bolt extraction hole
  • Use a bolt extractor, a left-handed thread tool, to screw into the bolt shank and remove it
  • Be cautious not to break the extractor off in the bolt shank
  • If the bolt is corroded, success may be low, but material failure increases the chances of removal
  • Clean the threads with a thread chaser or thread cleaner after removing the bolt
  • If the threads are severely damaged, consider using a Heli-Coil threaded insert for thread replacement

Did You Know?

1. In the early 1900s, William N. McGovern invented a bolt extractor that allowed for easier removal of broken bolts. This invention revolutionized the process of extracting bolts and greatly simplified the task of drilling them out.

2. Did you know that drilling out a bolt requires different drills depending on its material? For example, when drilling out a stainless steel bolt, it is advisable to use cobalt or carbide drill bits as they are specifically designed to withstand the hardness of this material.

3. The technique of drilling out a bolt can also be applied to remove stripped screw heads. By drilling into the screw head and then using an extractor, it is possible to remove a stripped or damaged screw with ease.

4. When drilling out a bolt, it is important to remember that heat can significantly affect the process. To prevent overheating, it is recommended to use cutting fluid or lubricant while drilling. This helps dissipate the heat, prolongs the life of the drill bit, and ensures that the bolt can be removed more effectively.

5. While drilling out a bolt can be a useful technique, it is important to exercise caution. The process can weaken the surrounding material, so it is crucial to take necessary safety precautions, such as wearing protective gear and maintaining stability during drilling to avoid accidents.

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1. Introduction: The Difficulty Of Removing A Broken Bolt, Screw, Or Stud

Removing a broken bolt, screw, or stud can be a challenging and frustrating task. Whether it’s due to corrosion, bolt locking, fastener fatigue, or overstressing, broken fasteners can present a significant obstacle when trying to repair or replace them. In some cases, a hammer and chisel may be sufficient to remove the broken fastener, but when that method fails, drilling and using a bolt extractor are necessary.

If the fastener is stuck in the threads, it may need to be drilled out just shy of the threads to make room for a bolt extractor. Summit Racing Equipment and Harbor Freight offer a variety of bolt extraction solutions, including bolt extractors and threaded inserts like the Heli-Coil. These tools can help restore damaged threads and make bolt removal more manageable.

2. Tools And Techniques For Drilling Out Bolts

When it comes to drilling out a bolt for removal, there are a few essential tools and techniques that can make the task easier:

  1. Center-punch the broken fastener to create a starting point for drilling.
  2. Drill a small pilot hole using a high-quality titanium or cobalt drill bit. Start with a 1/8-inch pilot hole and gradually increase the size with a 1/4-inch drill bit to open up the hole.

To ensure there is enough room for the bolt extractor to grip the remaining bolt shank securely, progressively bore out the bolt extraction hole until there is not much bolt shank left.

The bolt extractor is a left-handed thread tool that screws into the bolt shank in the opposite direction, allowing it to grip and remove the broken fastener. However, be cautious not to break the bolt extractor off in the fastener, as it can be harder than most drill bits and make removal nearly impossible.

Using heat or penetrating lubricant can also aid in bolt removal by loosening any corrosion or rust that may be causing resistance. However, it’s important to exercise caution when using heat, as too much heat can cause damage to surrounding components.

In summary:

  • Center-punch the broken fastener
  • Drill a small pilot hole and gradually increase the size
  • Bore out the bolt extraction hole progressively
  • Use a left-handed thread bolt extractor to grip and remove the broken fastener
  • Consider using heat or penetrating lubricant, but be cautious

Remember to approach the task with patience and care to avoid further complications or damage.

3. Using A Bolt Extractor For Removal

A bolt extractor is an incredibly useful tool for removing broken bolts, screws, or studs. These extractors come in a variety of sizes and are often sold in sets that include specialty end carbide burr tools for drilling broken bolts. When using a bolt extractor, it is crucial to follow the manufacturer’s instructions and use the appropriate size extractor for the broken fastener.

To use a bolt extractor, simply insert it into the drilled hole and turn it counterclockwise using a wrench or ratchet. The left-handed threading of the extractor allows it to grip the bolt shank and facilitate its removal. However, it is important to avoid applying excessive force, as this can break the extractor off in the fastener and lead to further complications.

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4. Repairing Or Replacing Damaged Threads With A Heli-Coil Insert

Heli-Coil Inserts: The Ultimate Solution for Repairing Damaged Threads

When it comes to repairing or replacing badly damaged or non-existent threads, the Heli-Coil insert is the go-to solution. Available from Summit Racing Equipment, the Heli-Coil insert is widely recognized as the industry standard for thread repair. It is capable of effectively working with various materials such as aluminum, magnesium, cast iron, and bronze.

The versatility of Heli-Coil inserts makes them suitable for restoring damaged threads in a wide range of components. From spark plug holes and carburetor fuel inlets to transmission and engine castings, oil drain plugs, exhaust and intake manifolds, cylinder heads, brake calipers, and suspension components, these inserts deliver reliable and durable results when salvage is not an option.

To ensure a secure and functional threaded connection, it is crucial to carefully follow the installation instructions provided by the manufacturer when using Heli-Coil inserts. This ensures that the inserts are properly installed, providing a long-lasting solution for damaged threads.

5. Tips For Successful Bolt Removal

Successfully removing a broken bolt, screw, or stud requires a combination of tools, techniques, and effort. While bolt removal can sometimes be challenging, following these tips can increase the chances of success:

  • Aim for the center when removing a broken fastener to prevent the drill bit from wandering or damaging the surrounding material.
  • Start with a small pilot hole to create a starting point for drilling, gradually increasing the size to open up the hole.
  • Welding a nut onto the broken bolt can make it easier to turn and facilitate its removal, but only attempt this method if enough of the fastener is sticking out.
  • Use left-handed drill bits for stubborn screws, as their reverse threading can help loosen the broken fastener during drilling.
  • Apply heat or penetrating lubricant to aid in bolt removal, particularly when dealing with corrosion or rust.
  • After successfully removing the bolt, use a thread chaser or thread cleaner to clean up dirty or damaged bolt hole threads.
  • Consider using a Heli-Coil threaded insert for thread replacement when threads are badly damaged or non-existent.

6. High-Quality Drill Bits And Sets For Drilling Out Bolts

Having high-quality drill bits and sets is essential when drilling out bolts, screws, or studs. Drill Bit Warehouse offers a wide range of durable and reliable drill bits that are suitable for various professions, including locksmiths, plumbers, electricians, contractors, and mechanics. With over 40 years of experience in the industry, Drill Bit Warehouse provides dedicated and experienced support to ensure customers find the right tools for their specific needs.

The drill bits available at Drill Bit Warehouse are designed to be easy to use and can cut through different materials with minimal effort. These high-quality drill bits ensure precise and efficient drilling, making them ideal for tasks such as drilling out broken fasteners. Whether you’re working with metal, wood, or other materials, Drill Bit Warehouse has the tools you need to get the job done effectively.

In conclusion, removing a broken bolt, screw, or stud can be a challenging task. However, by using the right tools and techniques, such as drilling, using a bolt extractor, and repairing or replacing damaged threads with a Heli-Coil insert, successful bolt removal is possible. Additionally, following tips for successful bolt removal and ensuring the use of high-quality drill bits and sets can further enhance the chances of a smooth and efficient process.

  • Use high-quality drill bits and sets
  • Choose the appropriate bit for the material being drilled
  • Use proper drilling techniques
  • Consider using a bolt extractor if necessary
  • Repair or replace damaged threads with a Heli-Coil insert
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Frequently Asked Questions

Can I drill through a bolt to remove it?

Yes, drilling through a bolt to remove it is a viable option. Begin by creating a small 1/8-inch pilot hole as a guide for the subsequent drill bits. The goal is to gradually widen the hole, removing most of the bolt shank in the process. This progressive boring technique will facilitate easier removal of the bolt.

What kind of drill bit do I need to drill out a bolt?

To drill out a bolt, it is recommended to use a cobalt center drill bit. The strong cobalt material ensures that you can apply sufficient pressure without risking the bit breaking. Start the hole with the tip of the cobalt center drill bit and then proceed with cobalt drill bits sized to an EZ-Out. It is advisable to avoid low-quality drill bits from brands like HF and focus on obtaining reliable and durable ones for a smooth drilling experience.

How do you soften bolts?

To soften bolts, a process called annealing is commonly employed. First, the steel bolts are heated in a forge or a heat treat oven, gradually increasing the temperature until the steel reaches a specific austenite region. Once the steel has reached the designated austenite temperature, it is kept at this temperature for around thirty minutes. The next step involves slowly lowering the temperature of the steel, although the speed at which it is lowered depends on the specific grade of the steel. Through this meticulous process of heating and cooling, the bolts are effectively softened, making them more malleable and easier to work with.

How do you drill out a stainless steel bolt?

When drilling out a stainless steel bolt, it is important to start by selecting the appropriate drill bit. Since stainless steel is a tough metal, a High-Speed Steel (HSS) drill bit with sharp edges is necessary for effective cutting. It is also crucial to choose a drill bit with a large point angle, preferably above 130 degrees, when dealing with hardened stainless steel. This will ensure that the drill can penetrate the bolt effectively and without excessive wear on the bit. With the right tools, patience, and steady pressure, you can successfully drill out a stainless steel bolt.

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