How to Remove a Stripped Bolt

A stripped bolt can be one of the most frustrating things to encounter when working on a mechanical project. The bolt head is rounded off or “stripped” so a wrench or socket can no longer grip it and apply turning force. Removing a stripped bolt requires some patience and specialized tools, but is doable with the right technique. Here is a step-by-step guide on how to remove a stripped bolt.

Preparing to Remove the Bolt

Before trying to remove the stripped bolt, take a few preparatory steps:

Gather the Proper Tools

You will need the following tools:

  • Bolt extractor set – Contains left-handed drill bits, reverse-threaded extractors, and slide hammer
  • Cutting torch – For heating and cutting through stubborn bolts
  • Lubricants – Penetrating oil, WD-40, etc to help loosen the bolt
  • Vice grips or locking pliers – To grip and turn the stripped bolt
  • Dremel or die grinder – To grind away and smooth stripped surfaces
  • Socket set – To find a socket that best fits the stripped bolt
  • Breaker bar – For extra turning leverage when loosening the bolt

Having the right tools for the job will make all the difference. Investing in a quality bolt extractor set pays dividends when encountering stuck, rounded, and stripped bolts.

Secure and Support the Workpiece

The bolt likely connects two or more parts. Make sure the workpiece is properly supported so that force can be applied to the stripped bolt without damaging the workpiece. Use jack stands, blocks, vices, or clamps to hold the workpiece steady.

Lubricate the Bolt

Apply a penetrating lubricant like WD-40 or PB Blaster to the bolt. Ensure the lubricant works its way into the threads via the bolt head and nut end. Let it soak for 10-15 minutes then reapply. The lubricant will loosen rust and corrosion to aid turning the bolt.

Match Socket Size

Examine the stripped bolt head and determine the closest socket size match. You want the socket to fit the bolt head as tightly as possible. This ensures maximum grip and turning force can be applied.

Having addressed these preparation steps, you’re ready to attempt extracting the stripped bolt.

Method 1 – Use a Bolt Extractor

Bolt extractor sets are made specifically for removing stripped, stuck, and stubborn bolts like this. Here is how to use them effectively:

Step 1 – Drill a Guide Hole

Use a left-handed drill bit the same diameter as the stripped bolt shaft. Keep the bit centered and drill a hole deep into the bolt, at least 3/4 of the bolt’s length. This guide hole centers the extractor and provides space for chips.

Step 2 – Install Extractor

Choose an extractor bit that matches the bolt diameter. Coat the extractor in cutting oil and tap it into the drilled guide hole with a hammer. The extractor’s left-hand thread will bite into the bolt as you rotate it counterclockwise.

Step 3 – Engage Slide Hammer

With the extractor set in the bolt, thread the slide hammer on. The slide hammer provides added force to help “shock” the extractor and bolt free. Use short, firm strokes and avoid hitting the workpiece.

Step 4 – Turn the Extractor

Place a wrench on the extractor and slowly turn counterclockwise while applying steady pressure. Keep turning as the extractor reverses the stuck bolt out.

Bolt extractors make removing stripped bolts straightforward. The key things to remember are drilling a centered guide hole, selecting the right sized extractor, and using controlled force.

Method 2 – Use a Dremel or Grinder

If a bolt extractor set is unavailable, the next best option is using a rotary tool like a Dremel or die grinder. Here is how to employ this technique:

Step 1 – Grind the Bolt Head

Use a cutting wheel or carbide bit to grind away the stripped top of the bolt head. Remove any stripped or rounded off areas. The goal is to create a flat surface for gripping with a wrench or pliers.

Step 2 – Smooth the Edges

Run the rotary tool over the ground surface to smooth out any sharp burrs or uneven edges. This allows for clean contact with the wrench or pliers.

Step 3 – Widen Flats

If needed, use a grinding cone bit to widen the flattened sections on the bolt head. This gives more surface area for gripping the sides of the bolt.

Step 4 – Grip and Turn

Using a wrench, vice grips, or locking pliers, take hold of the ground bolt head. Fit the tool’s jaws to the flat sections created. Apply penetrating lubricant. Then firmly grip and turn counterclockwise to extract the bolt.

Grinding and smoothing a new gripping surface on stubborn stripped bolts often does the trick for removal. It takes some time and care but can be done with basic rotary tools.

Method 3 – Cut the Bolt Out

In the most difficult situations, cutting the entire bolt and nut free may be required. Use great caution here, as cutting torches can damage components.

Step 1 – Protect the Workpiece

Shield any nearby parts vulnerable to heat damage. Use a thermal blanket, aluminum foil, or high-temp paint. Prevent burning electrical wires or plastic components.

Step 2 – Heat the Nut

Focus the torch flame on the nut end of the bolt first. Heat slowly, moving the flame around the nut circumference. This allows the penetrating lubricant to further soak the threads.

Step 3 – Heat the Bolt

Expand the flame to envelop the bolt shaft and head. Keep heating evenly until the bolt begins glowing red. The goal is to bring the entire bolt up to high heat.

Step 4 – Cut the Bolt Shaft

Using the torch tip, slowly cut through a point along the bolt shaft keeping hands clear. The head and nut end will come apart once cut. Repeat to cut the remaining nut if needed.

Step 5 – Grind the Edges

Use an angle grinder to smooth any jagged edges. File down and treat the cut surfaces to prevent rusting.

Heating and cutting seized or broken bolts is a last resort method. But for hopelessly stuck bolts, it may be the only way to remove them and continue repairs.

Removing Small or Hard to Reach Bolts

The methods above focus on standard hex head bolts. Smaller bolts or ones located in hard to reach areas require some alternate techniques:

  • Small/fine bolts – Use jewelry files or hacksaw to carefully slot the bolt head. Protect surroundings from filings. An extracted bolt can then fit a flathead screwdriver.
  • Recessed bolts – Grind a fitting wrench end to reach recessed socket bolts. Extension bars also help reach into deep recesses.
  • Rounded off heads – Superglue or epoxy a same-sized nut onto the rounded head. Let bond completely. The nut gives fresh corners to grip with wrench.
  • Rust-welded – Soak thoroughly in penetrating oil. Try tightening slightly before loosening to break rust seal. Heating can expand and loosen as well.
  • Spun out bolts – Weld a spare nut onto threads and turn out. Drill through bolt, insert hardened screw, and remove.

In all cases, patience and gentle application of increasing force pays off. Rushing often leads to damaged bolts or workpieces. Think through each situation carefully.

Preventing Future Stripped Bolts

Prevention is always preferable to having to remove a stripped bolt. Here are tips to avoid this issue in future projects:

  • Use proper sized tools – Avoid undersized open-end wrenches that can strip and round off corners.
  • Maintain proper torque – Do not over or under tighten. Use torque wrench for accuracy.
  • Use anti-seize lubricant – Lubricates threads and prevents rust bonding.
  • Tighten in sequence – Follow criss-cross tightening pattern to spread load.
  • Use bolts/nuts rated for the job – Match strength ratings and material hardness.
  • Inspect condition – Replace any questionable bolts/nuts before fully stripping.

Proper tool use, torque, lubrication, and maintenance makes stripped bolts far less likely. But if one still occurs, this guide gives the key methods of removing problem bolts to complete the repair.

Frequently Asked Questions About Removing Stripped Bolts

Removing a stripped bolt can be tricky. Here are answers to some common questions about dealing with stripped, stuck, and seized bolts.

What is the easiest way to remove a stripped bolt?

The easiest method is to use a bolt extractor set. Extractors are made to reverse and back seized bolts out of holes with minimal effort. First drill a guide hole, then insert a matching extractor and turn counterclockwise using pliers or a slide hammer. Extractors utilize left-handed thread design to grab and back the bolt out when turned.

Can you remove a stripped bolt without a drill?

Yes, it is possible to remove stripped bolts without a drill using locking pliers or vice grips. Tightly clamp the pliers onto the bolt head after smoothing the surface with a grinder. Fit as tightly as possible and turn counterclockwise slowly but forcefully. Penetrating lubricants help loosen the threads. Pliers can chew up soft bolt heads, so harden first with heat or epoxy if needed.

What solvent removes stripped bolts?

Penetrating solvents like WD-40, PB Blaster, Liquid Wrench, or Kroil work best to free stuck, seized, and stripped bolts. The solvents thin, lubricate, and loosen rust and corrosion buildup. Spray or drip solvent into the bolt crevices and let sit 10-15 minutes before attempting to turn. Reapply more solvent and let dwell again if the bolt still doesn’t move. This softens the threads for extraction.

Can you use heat to remove a stripped bolt?

Yes, applying localized heat can help free a stripped, stuck bolt by expanding and breaking any rust bonds. Use a small torch or induction heater to slowly heat the exposed bolt shaft and especially the threads underneath the bolt head. The heat expands the metal and loosens any grit or rust welds, allowing the bolt to turn out. Just take care to avoid overheating surrounding parts.

What is the best way to remove a broken bolt?

If the bolt head snaps off, leaving just the threads in the hole, use an easy out bolt extractor by drilling a hole into the bolt remnant and threading in the extractor. For flush or recessed broken bolts, center punch a divot before drilling the hole to guide the bit. Broken bolts can also be ground down flush and slotted for a flat head screwdriver or gripped tightly with locking pliers.

How do you remove rounded bolts?

Carefully grind the rounded surfaces flat to create a fresh gripping pattern for pliers or a wrench. Use a die grinder or Dremel with a metal cutting wheel at slow speed. Make a few flat sides for jaws to grab onto. Smooth away sharp edges, then fit pliers and firmly grip the new flats while unscrewing the bolt.

What tools are used to remove stripped screws?

  • Slotted screwdriver – hammered into the screw head and turned out
  • Pliers – to grip and turn out the fastener
  • Screw extractor – reverse thread drill bits
  • Rotary tools – to grind a slot for flathead driver
  • Soldering iron – heats screw and frees corrosion

First use penetrating oil or solvent. Pliers provide good grip if the head is not too damaged. For stripped screws with no usable head, extractors are ideal and help prevent further damage.

Conclusion

Stripped, stuck, and seized bolts can derail any repair project. But in most cases, following the techniques here will successfully remove problem fasteners. The keys are using proper tools, applying patience and controlled force, and taking steps to prevent future bolting issues. With the right methods, even hopelessly stripped bolts can be conquered.


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