It’s best not to strip the bolt to begin with. That being said, there are times when we encounter bolts other people have stripped. Both the head of the bolt or the nut and the threads can be stripped. When the head of the bolt or the nut is rounded off or stripped and the bolt is tight, you have a problem.

Dealing with a stripped bolt can be frustrating and can cost a lot of extra time when you’re trying to remove and replace anything that bolt or nut holds in place. Tasks like removing a tire is a fairly simple procedure, but a stripped bolt can make it twice as hard. If the nut is rounded off, you have to figure out how to grip it tightly enough to break it loose. If the threads are damaged or the nut is galled to the stud by overtightening, that multiplies the problem.

Methods differ based on how bad the bolt is stripped, but here are some pointers that may help. Read on to find out how to remove a stripped bolt using simple tools.

What Causes Stripping?

First things first一what causes stripping?

If a lug nut is stripped, it means the head’s been rounded off.

A stripped bolt is often the result of overtightening or using a twelve point socket or a socket that is a bit too large. If you often use an impact wrench to tighten the bolts, when the socket begins to slip, it rapidly rounds off the corners of the nut or bolt to the point that even the right size socket won’t work.

different impact wrenches — Using an impact wrench on lug nuts should only be done using the proper torque stick (see illustration) to prevent overtorquing. Different color torque sticks apply different amounts of torque. | Image Source: Richard McCuistian

Corrosion is another cause of stripping, and it’s related to overtightening, too. Rust and heat are aslo factors, as with bolts that hold the header pipe up to the exhaust.

Overtightening the bolt can warp and compress the metal, eventually exposing it to the elements. This is known as galvanic corrosion.

close up shot of a rounded off bolt — This rounded off bolt was removed using a smaller socket than the original along with valve grinding compound. | Image Source: Richard McCuistian

Galvanic corrosion or bimetallic corrosion is a chemical reaction that causes one type of metal to corrode in preference to another.

This type of corrosion occurs when two different metals are exposed to a conductive solution and are electrically charged.

How to Remove a Stripped Bolt

There are several ways to remove a stripped bolt without taking too much of your time. Here are some techniques you can try:

Try the Breaker Bar-Socket-Pipe Method With Some Valve Grinding Compound

Most stripped lug nuts have smaller corners than the original size they came in. Try using a smaller socket, and use a hammer to tap the socket until it fits the lug nut.

Then, connect a breaker bar to the socket, and try to remove the nut. If you need extra leverage, you can attach a pipe at the end of the bar.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Valve grinding compound (a gritty gray paste) smeared inside the socket also helps much of the time. Some diesel mechanics will dip a socket in oil and then drop it in sand for the same effect. Every grit of sand or grinding compound provides another small purchase point that usually gets the job done.

exhaust header bolt image — The exhaust header bolt in the photo was originally a 15mm head but the heat, rust, and time made the head just a bit smaller, so a 9/16 socket was hammered onto the head of the bolt to remove it. A new bolt was installed at the end of the job. Old exhaust parts also have threads that try to seize, multiplying the problem, so the replacement bolt was installed using anti-seize compound on the threads. | Image Source: Richard McCuistian

Use the Chisel and Hammer Combo

When using the chisel and hammer combo, keep in mind that the goal is to get the lug nut to spin a little, not to break it in half, and try not to damage the threads on the lug stud.

chisel and hammer combo illustration — Illustration demonstrating the chisel and hammer combo | Image Source: Richard McCuistian

You’ll need a set of chisels to find the best size for the stripped bolt. Once you’ve found the right size, rest the chisel on the edge of the lug nut flat so that the pressure you’re putting on the nut with the chisel will spin the nut in the direction it needs to go to come off, which is almost always counter-clockwise.

Strike the chisel with a hammer until the lug nut spins. From there, you can use a regular socket to unscrew the lug nut if it isn’t so damaged by the chisel that a regular socket won’t fit.

image of a rounded socket head transfer — This socket head transfer case fill plug was rounded out internally, but some valve grinding compound and a TORX bit brought it out. | Image Source: Richard McCuistian

Use an Impact Wrench

An impact wrench is designed to tighten and loosen lug nuts without requiring too much effort.

An impact wrench is a handheld electric device that can rotate a socket wrench at a high speed. It usually has a torque-limiting device that automatically stops the socket wrench’s rotation.

Pro Tip: The problem is that if the socket isn’t completely on the bolt or if the bolt is already rounded off, the impact wrench will make the problem worse really fast, especially if you aren’t using a six-point socket. Inspect the bolt closely and the tool you have before proceeding.

Use a Bolt Extractor

A bolt or screw extractor is a device that works with adjustable spanners, drills, and vice grip pliers. This tool has a reverse thread that can remove stripped bolts without damaging the thread.

various bolt extractor sockets — There are bolt extractor sockets with internal fluted cuts for gripping stripped bolt heads and nuts but they only work some of the time. | Image Source: Richard McCuistian

Try Using a Drill

Using a drill sounds like a tedious process when trying to remove a stripped bolt, but it’s actually safer than using an air hammer, air chisel, or torch. Sometimes it’s the only way.

Pro Tip: Get some really good drill bits, center punch the broken bolt, and spin the drill very slowly so as not to heat up the bit and the bolt. This makes the bit softer and the bolt harder and brings the job to a halt. Lubricate the drilling area with WD40 or even a bit of engine oil while drilling to improve the cut. Hold the drill straight and be careful not to break the bit. After you’ve drilled a hole in the center of the bolt, you can usually use a screw extractor to remove it.

If you’re looking to try this method, make sure to start with a small drill bit and work your way up.

Begin with an indentation at the center of the lug nut to prevent the drill from slipping, or you can use a burr attachment with a die grinder.

When using a drill to remove a stripped lug nut, the drill bit can get dull. To prevent this from happening, dip the drill bit into a cup of oil every once in a while.

The wheel should slide out easily after drilling. But if the lug nut is still stuck, you can use a pair of pliers to pull it out.

Try Welding

Welding can be quite complicated if you lack the necessary skills, but you can always find a welder to do the job for you.

You can try welding on top of the stripped lug nut, and use a breaker bar to remove it completely. Note that if you’re not a good welder, this probably won’t work.

Also, keep in mind that this method won’t work on all vehicles, especially if the wheels are deep.

A Thing or Two About Lug Nuts

Lug nuts are small and simple parts that make a huge difference in how your vehicle performs. Here are a few things you should know about lug nuts.

Function

Lug nuts hold the wheels to the brake discs, drums, and the entire wheel bearing assembly.

In most cases, studs in the brakes or bearing assemblies accompany the lug nuts to keep the wheels in place.

Most lug nuts are tapered to let the wheel stud keep the wheel in place. A tapered design also helps create a suitable surface for the lug nuts, preventing them from loosening.

Types

Alloy wheels usually have a shank-nut-type lug nut that isn’t tapered. This type of lug nut isn’t compatible with every wheel, so make sure that the corresponding nut type for your wheel is installed.

Some aftermarket manufacturers sell stud conversion kits that let drivers replace their lug bolts with a conventional stud and lug nut.

Sizes

Lug nuts are sized according to the thread size of the stud they’re attached to. Typically, you’ll find the diameter and number of threads per inch stated in the packaging.

Vehicles can have right-hand (RH) or left-hand (LH) threads.

7/16-20RH is a common size for lug nuts. 7/16 represents the wheel diameter and 20 pertains to the number of threads.

Key Takeaways

Removing a stripped bolt can make a simple task time-consuming一especially when you’re in a hurry to remove one of your wheels.

This issue is a result of overtightening the lug nuts and corrosion.

Fortunately, there are several ways you can deal with this problem without it being a hassle.

Some of the common things you can use include a bolt extractor, impact wrench, drill, and breaker bar.

About The Authors

Written By

CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By

Richard McCuistian

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.