How To Remove A Rounded Bolt

Removing a rounded bolt can be a frustrating and time-consuming task. However, with the right tools and techniques, it is possible to remove even the most stubborn rounded bolts. In this article, we will guide you through the steps on how to remove a rounded bolt, providing you with various methods and tips to ensure a successful outcome.

Before attempting to remove a rounded bolt, it is essential to gather the necessary tools. These include a set of pliers, a wrench, a hammer, a chisel, and a penetrating lubricant. Once you have gathered your tools, you can begin the process of removing the bolt.

The first step is to try to grip the bolt with a pair of pliers. If the bolt is not too badly rounded, you may be able to get a good enough grip to turn it. If you are unable to grip the bolt with pliers, you can try using a wrench. However, be careful not to apply too much force with the wrench, as this could damage the bolt or the wrench.

Causes of Rounded Bolts

There are various factors that can contribute to a bolt becoming rounded, hindering its removal. Understanding these common causes is crucial in devising effective strategies to address this issue:

Overtightening

Excessive force applied while tightening the bolt can damage its head, leading to rounding. This occurs when the torque applied exceeds the bolt’s specific design specifications. Overtightening is particularly prevalent when using power tools, as they can generate high levels of torque if not properly calibrated and controlled.

Corrosion

Exposure to moisture, salts, and chemicals can cause bolts to corrode, resulting in the formation of rust and other surface imperfections. Over time, these deposits can accumulate on the bolt’s head, making it difficult to grip with conventional tools and increasing the risk of rounding during removal attempts.

Damaged Tool Insertion

Using worn or misaligned tools to remove a bolt can also contribute to rounding. Damaged or dull bits may not properly engage with the bolt’s head, resulting in slippage and further damage to its edges. Similarly, tools that are not perpendicular to the bolt’s axis can apply uneven force, leading to rounding along one side.

Seized Bolts

In certain cases, bolts can become seized due to rust, corrosion, or other factors that inhibit their movement. Applying excessive force to remove a seized bolt can easily result in rounding, as the bolt’s head is subjected to uneven stress and deformation.

Essential Tools

When embarking on the task of removing a rounded bolt, having the appropriate tools at your disposal is crucial for success. Here is a comprehensive list of essential tools you will need:

Bolt Extractor Set

Bolt extractor sets come with various sizes and shapes of extractors designed specifically for removing damaged or rounded bolts. They work by gripping the sides of the bolt and turning it counterclockwise. It is recommended to invest in a high-quality set with a range of sizes to handle different bolt diameters.

Features of Bolt Extractors:

Hardened steel construction for durability
Reverse cutting teeth for maximum grip
Available in both fractional and metric sizes

How to Use Bolt Extractors:

Select the appropriate extractor size for the bolt.
Drill a pilot hole into the center of the bolt.
Insert the extractor into the hole and tap it in with a hammer.
Use a wrench to turn the extractor counterclockwise to remove the bolt.

Hammer and Punch Method

The hammer and punch method is a more straightforward approach that involves using a hammer and a punch to loosen the rounded bolt. Here’s a detailed guide with extra details to make the process more effective:

Step 1: Gather Your Tools

You’ll need a hammer, a punch, a socket wrench, and a socket that fits the rounded bolt head.

Step 2: Position the Punch

Place the tip of the punch into the center of the rounded bolt head. Make sure the punch is aligned perpendicular to the bolt head.

Step 3: Strike the Punch

Using the hammer, strike the punch with a firm, sharp blow. The goal is to create a depression or notch in the bolt head that will give the socket wrench something to grip onto.

Step 4: Repeat the Process

Continue striking the punch at different angles around the bolt head until you have created a series of depressions. The more depressions you create, the better the socket wrench will be able to grip the bolt.

Step 5: Use the Socket Wrench

Once you have created sufficient depressions, insert the socket wrench into the bolt head and try to turn it. If the bolt does not move, tap the wrench with a hammer while applying pressure.

Step 6: Repeat the Process

If the bolt still doesn’t move, repeat steps 3-5 until the bolt loosens and can be removed.

Vise Grip Technique

If the bolt is relatively small and accessible, you can use a vise grip to remove it. This method is effective even on rounded bolts, as the vise grip’s teeth will bite into the metal and provide a secure hold.

1. Secure the Bolt: Clamp the vise grip onto the bolt as close to the head as possible. Ensure the teeth are gripping the bolt tightly.
2. Apply Leverage: Use a wrench or socket to turn the vise grip. Apply steady pressure and turn counterclockwise to loosen the bolt.
3. Increase Grip if Needed: If the bolt is particularly stubborn, you may need to increase the vise grip’s grip. To do this, tighten the adjusting screw on the vise grip.
4. Alternate Gripping Positions: If the bolt is still difficult to remove, try alternate gripping positions. Move the vise grip closer to the bolt head or towards the tip. This can help distribute force more effectively and break free the bolt.

Tip: For larger bolts or bolts that are difficult to access, consider using a bolt extractor or a center punch and hammer to create a new groove for the wrench or socket.

Bolt Extractor Use

Bolt extractors are specialized tools designed to remove damaged or rounded bolts. They typically consist of a tapered or fluted body with spiral grooves that bite into the bolt’s damaged surface.

To use a bolt extractor, follow these steps:

Select the appropriate extractor size for the bolt.
Center the extractor over the bolt and tap it into place with a hammer.
Attach a wrench or socket to the extractor and turn it counterclockwise to loosen the bolt.
If the bolt is particularly stubborn, apply heat to the extractor using a torch or heat gun.
Once the bolt is loose, remove the extractor and the bolt.

Advanced Bolt Extractor Techniques

In some cases, you may need to use advanced techniques to remove a rounded bolt with an extractor.

Table: Advanced Bolt Extractor Techniques

Technique	Description
Double Nutting	Place a nut on the damaged bolt, then place another nut on top of it and tighten them together. This can help increase the grip on the bolt and make it easier to turn.
Reverse Drilling and Tapping	Drill a small hole in the center of the rounded bolt and tap it for a screw extractor. This can create a new grip surface for the extractor.
Weld a Nut	Weld a nut to the damaged portion of the bolt and use it to turn the bolt out.

Heating and Cooling Approach

This method involves alternating between heating and cooling the bolt to break down the corrosion and loosen it. Here’s a detailed guide on how to do it:

1. Heat the Bolt

Use a heat gun or torch to apply heat directly to the bolt head. Focus on the area around the rounded edges, but avoid overheating the bolt.

2. Apply Penetrating Oil

While the bolt is still hot, apply a generous amount of penetrating oil to the threads. The oil will penetrate the corrosion and lubricate the threads.

3. Cool the Bolt Quickly

Use a can of compressed air or cold water to quickly cool the bolt. The sudden temperature change will cause the metal to contract, breaking down the corrosion.

4. Repeat the Process

Repeat steps 1-3 several times until the bolt starts to loosen. Be patient, as this process may take several cycles.

5. Use a Bolt Extractor

If the bolt is still too tight to remove, use a bolt extractor. This tool has reverse-threaded teeth that bite into the rounded head and allow you to unscrew the bolt.

6. Advanced Techniques for Stubborn Bolts

For particularly stubborn bolts, consider these advanced techniques:

Technique	Description
Oxyacetylene Torch	Use an oxyacetylene torch to heat the bolt intensely. Cool with compressed air and repeat until the bolt loosens.
Induction Heating	Use an induction heater to create an electromagnetic field that heats the bolt from the inside out. This method allows precise heating without damaging surrounding areas.
Drilling and Tapping	Drill a hole in the center of the bolt head and insert a bolt extractor. This method requires precision and should be used as a last resort.

Drilling and Extraction

If the bolt is too badly rounded to grip with pliers or a wrench, you may need to drill it out. This is a more complicated process, but it can be done with the right tools and some patience.

To drill out a rounded bolt, you will need:

A drill
A drill bit that is slightly smaller than the diameter of the bolt
A center punch
A hammer
A bolt extractor
A wrench

Once you have gathered your tools, follow these steps:

Center punch the center of the bolt.
Drill a pilot hole into the center of the bolt, using a drill bit that is slightly smaller than the diameter of the bolt.
Insert the bolt extractor into the pilot hole and turn it counterclockwise.
If the bolt does not come out easily, tap the bolt extractor with a hammer to loosen it.
Once the bolt is loose, use a wrench to remove it completely.
Clean the threads of the bolt and the hole with a wire brush.
Apply a small amount of anti-seize compound to the threads of the bolt and insert it into the hole.
Tighten the bolt until it is snug.

Reverse Drilling Method

This method involves drilling a small hole into the center of the bolt, then reversing the direction of the drill and drilling out the remaining material. Here’s a step-by-step guide:

Center a small drill bit (about 1/16 inch) in the center of the bolt and drill a pilot hole about 1/4 inch deep.
Switch to a larger drill bit (about 1/8 inch) and drill another hole about 1/2 inch deep.
Continue drilling with larger bits until the hole is about 3/4 inch deep and the edges of the bolt are thin.
Reverse the direction of the drill and drill out the remaining material.
Use a punch or chisel to tap the bolt out of the hole.

Here’s a table summarizing the drill bit sizes and hole depths for different bolt sizes:

Bolt Size	Pilot Hole Depth	Subsequent Hole Depth
1/4 inch	1/4 inch	1/2 inch
5/16 inch	3/16 inch	3/4 inch
3/8 inch	1/8 inch	1 inch

Angle Grinder and Nut Method

If the bolt is too rounded to get a grip on with pliers or a wrench, you can use an angle grinder to cut a slot into the head of the bolt. Once you have a slot, you can use a flathead screwdriver to remove the bolt.

To use this method, you will need an angle grinder, a cutting disc, a flathead screwdriver, and safety glasses.

First, put on your safety glasses. Then, secure the bolt in a vice or on a stable surface. Next, use the angle grinder to cut a slot into the head of the bolt. Be careful not to cut too deeply into the bolt, as this could damage the threads.

Once you have cut a slot into the bolt, use a flathead screwdriver to turn the bolt counterclockwise to remove it.

More Details on Cutting a Slot

When cutting a slot into the bolt, it is important to use the correct technique to avoid damaging the bolt or yourself. Here are some tips for cutting a slot into a bolt:

Use a sharp cutting disc.
Hold the angle grinder steady and apply even pressure.
Cut slowly and carefully.
Be aware of the sparks and hot metal that will be produced.
Wear safety glasses and gloves.

Once you have cut a slot into the bolt, you can use a flathead screwdriver to remove the bolt. To do this, insert the screwdriver into the slot and turn the bolt counterclockwise. If the bolt is tight, you may need to use a wrench to provide additional leverage.

Professional Assistance

Sometimes, removing a rounded bolt is beyond the scope of DIY solutions. In such cases, it’s best to seek professional assistance from a mechanic or a machinist. They have the expertise, tools, and techniques to safely and effectively extract the bolt without damaging the surrounding components.

Here are some of the professional methods used to remove rounded bolts:

Method	Description
Weld a Nut	A nut is welded onto the rounded bolt, providing a new, square surface to grip.
Use an Extractor Socket	A specialized socket with reverse-tapered teeth bites into the rounded bolt and loosens it.
Drill and Tap	A hole is drilled into the bolt, and a new thread is cut to allow for a bolt extractor to be inserted.
Use a Bolt Removal Tool	Specialized tools are available that grip and remove rounded bolts without damaging the threads.

The choice of professional method will depend on factors such as the bolt’s size, location, and material. Mechanics and machinists can assess the situation and determine the most appropriate approach to safely remove the rounded bolt.

How to Remove a Rounded Bolt

Removing a rounded bolt can be a frustrating experience, but it’s not impossible. With the right tools and techniques, you can safely remove the bolt without damaging the surrounding material.

The first step is to try to grip the bolt with a pair of pliers. If the bolt is not too rounded, the pliers may be able to get enough traction to loosen it. If the pliers don’t work, you can try using a bolt extractor.

A bolt extractor is a tool that is specifically designed to remove rounded bolts. Bolt extractors come in a variety of sizes, so you’ll need to choose one that is the right size for the bolt you’re trying to remove.

To use a bolt extractor, first drill a hole in the center of the bolt. The hole should be deep enough to accommodate the bolt extractor. Then, insert the bolt extractor into the hole and turn it counterclockwise. The bolt extractor should bite into the bolt and loosen it.

Once the bolt is loose, you can use a wrench or pliers to remove it completely.