When working on machinery or vehicles, you may encounter a rounded bolt that seems impossible to remove. Rounded bolts can be caused by excessive force, corrosion, or poor-quality tools. Attempting to remove a rounded bolt with traditional methods can further damage the bolt head, making the problem worse. However, there are several effective techniques you can employ to loosen and extract a rounded bolt without causing further damage.
One method involves using a bolt extractor. Bolt extractors are specifically designed to grip and remove rounded bolts. They come in various sizes and shapes to accommodate different bolt sizes. To use a bolt extractor, first, select the appropriate size extractor that fits snugly inside the rounded bolt head. Insert the extractor into the bolt head and apply counterclockwise force using a wrench. The extractor’s teeth will bite into the damaged bolt head, allowing you to loosen and remove it.
Another technique for loosening a rounded bolt is to use a hammer and chisel. This method is suitable for bolts that are not excessively rusted or corroded. Place the chisel on the edge of the bolt head and strike it with a hammer in a counterclockwise direction. The chisel will create small nicks or grooves in the bolt head, providing you with a gripping surface to apply torque with a wrench. Continue tapping the chisel until the bolt head becomes loose enough to remove. If the bolt is very tight, you may need to use penetrating oil or heat to loosen it further before attempting to remove it.
Identifying the Stuck Bolt
When attempting to remove a rounded bolt, it is crucial to first identify the underlying cause of its seizure. This preliminary examination will determine the most appropriate course of action and prevent further damage to the bolt or surrounding components.
Signs of a Rounded Bolt:
The following observations may indicate a rounded bolt:
- Inability to engage the wrench or socket due to rounded edges
- Excessive slipping or stripping when applying force
- Visual deformation of the bolt head or nut, resulting in a non-hexagonal or non-circular shape
Causes of Bolt Seizure:
Several factors can contribute to bolt seizure, including:
- Corrosion and Rust: Exposure to moisture and oxygen can cause oxidation, leading to the formation of rust, which can bind the bolt to the mating surface.
- Overtightening: Excessive torque applied during installation can stretch and deform the bolt, making it difficult to remove.
- Cross-threading: Incorrect alignment during installation can cause the bolt to thread incorrectly, resulting in binding and damage.
Additional Considerations:
Before attempting any loosening techniques, it is also important to consider the following:
| Factor | Impact |
|---|---|
| Bolt material | Different materials exhibit varying degrees of hardness and susceptibility to damage. |
| Surrounding materials | Heat or chemical treatments may damage nearby components if not applied carefully. |
| Bolt accessibility | Limited access may restrict the use of certain tools or methods. |
Preparing the Necessary Tools
To effectively loosen a rounded bolt, you will need the appropriate tools. Here is a detailed breakdown of what you will require:
Bolts and Nuts
| Bolt Size | Nut Size |
|—|—|
| M6 | M6 |
| M8 | M8 |
| M10 | M10 |
| M12 | M12 |
| M14 | M14 |
Wrenches and Sockets
| Wrench Type | Socket Size |
|—|—|
| Open-End Wrench | Same as bolt size |
| Box-End Wrench | Same as bolt size |
| Pipe Wrench | Larger than bolt size |
Impact Tools
In case of stubborn bolts, impact tools can provide additional force:
| Impact Tool |
|—|—|
| Impact Gun |
| Impact Driver |
| Sledgehammer |
Additional Tools
| Tool | Purpose |
|—|—|
| Penetrating Oil | Lubricates and loosens bolts |
| Vise or Pliers | Holds bolts for easier removal |
| Wire Brush | Cleans bolt surfaces |
Applying Penetrating Oil
Penetrating oil is a specialized lubricant designed to seep into tight spaces and break down corrosion, making it an effective tool for loosening rounded bolts. To apply penetrating oil effectively:
1. Preparation
Clean the area around the bolt to remove any dirt or debris that could block the oil from penetrating. Use a wire brush or compressed air to do this.
2. Application
Apply the penetrating oil directly to the bolt threads and surrounding area using a spray nozzle or dropper. Allow the oil to penetrate for at least 15 minutes, or longer for more stubborn bolts.
3. Multiple Applications
To maximize the effectiveness of the penetrating oil, repeat the application process several times. Depending on the severity of the corrosion, you may need to wait for longer periods between applications. Here’s a suggested schedule for multiple applications:
| Application Number | Wait Time |
|---|---|
| 1 | 15 minutes |
| 2 | 30 minutes |
| 3 | 1 hour |
| 4 | Overnight (if possible) |
After each application, allow the oil to penetrate before attempting to loosen the bolt. If it remains stuck, repeat the process.
Using a Wrench or Spanner
Using a wrench or spanner is the traditional method to loosen rounded bolts. The key mechanism behind this technique is the high rotational torque generated by applying force perpendicular to the bolt’s axis. Here are the steps involved:
- Select the correct size wrench or spanner for the bolt. Using a wrench that is too small can slip, while a wrench that is too large can damage the bolt.
- Grip the wrench close to the head of the bolt for maximum leverage.
- Apply steady pressure and twist the wrench counterclockwise to loosen the bolt.
- If the bolt is particularly resistant, consider using a cheater bar or pipe to extend the length of the wrench, increasing the rotational torque.
Alternative Methods
In cases where using a wrench or spanner fails to loosen the bolt, various alternative methods can be employed. These methods often involve using specialized tools or strategies to bypass damaged bolt heads:
Hammer and Chisel
1. Use a hammer and cold chisel to create a slot or groove in the bolt head.
2. Insert a medium-sized flathead screwdriver or chisel into the groove.
3. Turn the screwdriver or chisel to break the bolt loose.
Vice Grips
1. Lock a pair of vice grips onto the bolt head as tightly as possible.
2. Use the vice grips’ handles to turn the bolt counterclockwise to loosen it.
3. Adjust the grip as needed to ensure a firm hold on the bolt.
Bolt Extractors
1. Use a drill bit to create a hole in the center of the bolt head.
2. Insert a bolt extractor into the hole and twist it counterclockwise to engage the threads.
3. Continue twisting the extractor to remove the bolt.
Applying Heat or Cold
Applying heat or cold to a rounded bolt can help to loosen it. Heat will expand the bolt, while cold will shrink it. This can help to break the bond between the bolt and the material it is in. To apply heat, you can use a torch or a heat gun. To apply cold, you can use a spray can of compressed air or a block of dry ice.
Heat
Heating the bolt and surrounding area is a great way to expand the material. This will loosen the bond between the bolt and the surrounding material, making it easier to remove. When using heat, there are a few things to keep in mind:
- Use caution: Heat can damage the bolt or the surrounding area if it is applied too much. Be careful not to overheat the bolt.
- Ventilate the area: Heating the bolt can create harmful fumes. Make sure to ventilate the area adequately.
- Use a heat sink: A heat sink can help protect the surrounding area from damage. A heat sink is a metal object that absorbs heat and dissipates it away, preventing the surrounding area from getting too hot.
Cold
Cooling the bolt is another effective method to break the bond between the bolt and the surrounding material. When the bolt is cooled, it will shrink slightly. This contraction can help to create a small gap between the bolt and the surrounding material. This gap can then be used to apply penetrating oil or other lubricants, which can help to further loosen the bolt.
- Use caution: Cooling the bolt too quickly can cause it to become brittle and break. Be careful not to cool the bolt too quickly.
- Ventilate the area: Cooling the bolt may produce fumes. Ventilate the area adequately.
- Use a heat sink: A heat sink can help protect the surrounding area from damage. A heat sink is a metal object that absorbs heat and dissipates it away, preventing the surrounding area from getting too cold.
| Heat | Cold | |
|---|---|---|
| Effect on bolt | Expands | Shrinks |
| Effect on surrounding material | Can expand | Can shrink |
| Safety precautions | Use caution, ventilate area, use heat sink | Use caution, ventilate area, use heat sink |
| Advantages | Can loosen stubborn bolts | Can be used on bolts that are damaged or have rounded heads |
| Disadvantages | Can damage bolt or surrounding area if applied incorrectly | May not be as effective as heat on some bolts |
Hammering on a Socket
This method involves using a socket wrench and a hammer to break the corrosion or rust that has seized the bolt. Follow these steps:
- Select the appropriate socket size for the bolt.
- Position the socket over the bolt and hammer it onto it with a few forceful strikes.
- Apply continuous pressure on the socket while hammering to drive it deeper onto the bolt.
- Use a strong hammer with a solid head to deliver powerful blows.
- Hammer repeatedly until the socket is seated firmly onto the bolt.
- Once the socket is secure, use a ratchet or wrench to apply torque and loosen the bolt. It may take several attempts to break the corrosion and loosen the bolt.
Here’s a table summarizing the process:
| Step | Action |
|---|---|
| 1 | Choose proper socket size |
| 2 | Hammer socket onto bolt |
| 3 | Apply continuous pressure |
| 4 | Use strong hammer |
| 5 | Hammer repeatedly |
| 6 | Use wrench to loosen bolt |
Using Vice Grips
Vice grips are a versatile tool that can be used to loosen rounded bolts when other methods have failed.
Here’s how to use vice grips to loosen a rounded bolt:
- Position the vice grips over the rounded bolt. Make sure that the jaws of the vice grips are fully engaged with the bolt.
- Apply pressure to the vice grips. You may need to use a lot of force to break the bolt loose.
- Once the bolt has been broken loose, you can use a wrench or socket to remove it completely.
| Tips for Using Vice Grips | |
|---|---|
| Use the correct size vice grips for the bolt. | |
| Place the vice grips as close to the head of the bolt as possible. | |
| Apply pressure to the vice grips slowly and evenly. |
If you are unable to loosen the bolt with vice grips, you may need to use a more specialized tool, such as a bolt extractor.
Cutting the Bolt
Additional Cutting Methods
If the aforementioned methods fail to loosen the bolt, consider these additional cutting techniques:
8. Bolt Extractors/Screw Extractors
Bolt extractors, also known as screw extractors, are specialized tools designed to remove broken or damaged bolts. They feature a reverse-threaded cone shape that grips the bolt and loosens it. To use a bolt extractor:
- Select an extractor slightly smaller than the bolt’s diameter.
- Drill a pilot hole into the bolt’s center, using a bit slightly smaller than the extractor’s diameter.
- Insert the extractor into the pilot hole and turn it counterclockwise using a wrench.
- If the bolt is still stuck, apply heat to the bolt and extractor using a heat gun or torch. This will expand the bolt and make it easier to loosen.
| Size | Use |
|---|---|
| 0 (smallest) | Screws smaller than 1/8 inch |
| 1 | Screws 1/8 to 3/16 inch |
| 2 | Screws 3/16 to 1/4 inch |
| 3 | Screws 1/4 to 5/16 inch |
| 4 (largest) | Screws larger than 5/16 inch |
Preventing Future Problems
Once you’ve successfully loosened a rounded bolt, it’s essential to take steps to prevent future problems. Here are some practical tips:
-
Use the right tools
Always use the correct size and type of wrench or socket for the bolt. Using the wrong tools can damage the bolt and make it more difficult to remove in the future.
-
Apply even pressure
When tightening or loosening a bolt, apply pressure evenly around the circumference of the bolt. This will help prevent the bolt from becoming rounded.
-
Use a lubricant
Applying a lubricant, such as WD-40 or penetrating oil, to the threads of the bolt before tightening can help reduce friction and prevent the bolt from seizing.
-
Avoid overtightening
Overtightening a bolt can damage the threads and make it more difficult to remove in the future. Tighten bolts only to the recommended torque specification.
-
Use anti-seize compound
Applying anti-seize compound to the threads of the bolt before tightening can help prevent the bolt from seizing and becoming difficult to remove.
-
Consider using a locking washer
Using a locking washer under the head of the bolt can help prevent the bolt from loosening over time.
-
Regularly inspect and maintain bolts
Periodically inspect bolts for signs of wear or damage. Tighten any loose bolts and replace any damaged bolts. This will help prevent problems from developing in the future.
-
Use high-quality bolts
Using high-quality bolts will help reduce the chances of them becoming rounded or damaged. High-quality bolts are typically made from stronger materials and have more precise threads.
-
Avoid using impact wrenches
Impact wrenches can apply excessive force to bolts, which can damage them and make them more difficult to remove. Use impact wrenches only when necessary.
-
Understand the difference between tightening and loosening torque
When tightening a bolt, apply the correct amount of torque to ensure it is secure. When loosening a bolt, apply a slightly higher amount of torque to break the bolt loose.
How To Loosen Rounded Bolt
When a bolt becomes rounded, it can be difficult to remove. However, there are several techniques that can be used to loosen a rounded bolt. These techniques include using a bolt extractor, using a hammer and chisel, or using a drill to create a new slot for the wrench.
If the bolt is only slightly rounded, it may be possible to use a pair of pliers to grip the bolt and turn it. However, if the bolt is severely rounded, it will be necessary to use one of the other techniques described below.
People Also Ask About How To Loosen Rounded Bolt
How do you remove a rounded screw without drilling it?
There are several ways to remove a rounded screw without drilling it. These include using a bolt extractor, using a hammer and chisel, or using a rubber band.
How do you drill out a rounded bolt?
To drill out a rounded bolt, you will need to use a drill bit that is slightly smaller than the diameter of the bolt. Drill a hole into the center of the bolt, and then use a bolt extractor to remove the bolt.
