If you’ve ever tried to remove a lawn mower blade nut only to find that it’s stripped, you know how frustrating it can be. But don’t worry, with the right tools and techniques, you can get that stubborn nut off and replace your blade.

Let’s take a look at how to remove a stripped lawn mower blade nut.

First, it’s important to assess the severity of the stripping. If the nut is only slightly stripped, you may be able to remove it with a regular wrench or pliers. However, if the stripping is severe, you may need to use more advanced techniques like bolt extractors or drilling the nut.

No matter the severity of the stripping, we’ll cover the tools and techniques you need to successfully remove that stubborn nut. So grab your tools and let’s get started.

Assess the Severity of the Stripping

You’ll need to gauge the severity of the grinding to get going on getting that stripped blade bolt off!

The first step is to assess how badly the nut is stripped. If the nut is only slightly stripped, you may be able to remove it with a pair of pliers or a wrench. However, if the nut is severely stripped, it may be necessary to use more advanced techniques.

Causes of stripped nuts can include using the wrong size wrench, overtightening the nut, or rust and corrosion. To prevent future stripping, make sure to use the correct size wrench and only tighten the nut to the recommended torque specifications.

Additionally, keep your lawn mower blades clean and free of rust and corrosion. Regular maintenance can go a long way in preventing stripped nuts and other issues.

Gather the Right Tools

To properly dismantle the fastener holding the blade in place, it’s essential to have the appropriate tools on hand. You’ll need a socket wrench with a socket that fits the nut, a breaker bar, and a pair of safety gloves.

Additionally, you may want to consider using a penetrating oil to loosen any rust or debris that may be present. When selecting your tools, it’s important to choose the right size socket to fit the nut snugly. An ill-fitting socket can cause further damage or make the removal process more difficult.

Safety measures should also be taken when handling the tools. Use a breaker bar for extra leverage, and ensure that the mower is turned off and the spark plug is disconnected to prevent accidental starting. Wearing protective gloves will also prevent injury from sharp blades or hot metal.

Apply Lubricant or Penetrating Oil

Apply Lubricant or Penetrating Oil

Before getting started, it’s like giving your car a shot of WD-40 to get rid of any rust or debris that may be sticking around. Applying lubricant or penetrating oil can significantly ease the process of removing a stripped lawn mower blade nut. 

The benefits of using lubricant are that it can penetrate the threads of the nut, loosen rust, and reduce friction between the nut and bolt. Additionally, it can help prevent further damage to the nut and bolt threads, which would make the removal process even more difficult.

There are several options when it comes to lubricants for removing stripped nuts. One of the most popular lubricants is WD-40. It is a versatile lubricant that can penetrate and loosen rust, making it easier to remove the nut. 

Another popular option is PB Blaster, which is specifically designed for penetrating rust and corrosion.

It is also effective in reducing friction between the nut and bolt. Other options include Liquid Wrench, Kroil, and AeroKroil. These lubricants are specifically designed for penetrating rust and corrosion, making them ideal for removing stripped lawn mower blade nuts.

WD-40Versatile and effective in penetrating rust
PB BlasterSpecifically designed for penetrating rust and corrosion
Liquid WrenchIdeal for removing rust and corrosion
KroilEffective in penetrating rust and corrosion
AeroKroilSpecifically designed for penetrating rust and corrosion

Remember to apply the lubricant or penetrating oil generously and allow it to sit for a few minutes before attempting to remove the stripped nut. 

This will give the lubricant enough time to work its way into the threads and reduce friction, making it easier to remove the nut. 

Use a Wrench or Pliers

Using a wrench or pliers, it’s like trying to unscrew a stuck jar lid, but with a little effort and the right technique, the nut can be loosened.

If you don’t have a wrench, you can use some wrench alternatives like a pair of pliers or a pipe wrench. However, be sure to use a tool that has a strong grip and won’t slip off the nut while you’re applying pressure.

When using a wrench or pliers, it’s important to use the right tightening technique. Don’t just twist the tool back and forth, as this can damage the nut and make it even harder to remove. Instead, apply steady pressure in one direction, using short, controlled movements until the nut starts to turn.

If the nut is still stuck, try applying some heat to the area around the nut to help loosen it.

Try Bolt Extractors

Bolt extractors are specialized tools designed to remove stripped, rusted, or seized bolts. They come in various sizes and shapes, and each type is designed to handle specific situations.

There are two main types of bolt extractors: spiral flute extractors and multi-spline extractors. Spiral flute extractors work by biting into the bolt and using the force of the rotation to loosen it. They are best suited for softer materials such as aluminum or copper. 

Multi-spline extractors, on the other hand, use a series of splines to grip the bolt and turn it out. They are better suited for harder materials like steel and are less likely to round off the bolt head. 

The benefits of using bolt extractors are clear – they can save you time, energy, and frustration by making an otherwise difficult job much easier.

Type of Bolt ExtractorBest Suited forAdvantages
Spiral Flute ExtractorSoft materials such as aluminum or copperUses the force of rotation to loosen bolts
Multi-Spline ExtractorHarder materials such as steelLess likely to round off bolt head, better grip on bolt

Use Heat

Use Heat

You may be surprised to know that applying heat can be a game-changer when dealing with a stubborn bolt. Here are some tips for using heat to remove a stripped lawn mower blade nut:

  1. Heat safety is crucial. Always wear heat-resistant gloves to protect your hands from burns. Make sure there aren’t any flammable materials nearby, and keep a fire extinguisher within reach.
  2. Use a propane torch to heat the nut for 30-60 seconds. Be sure to heat the nut evenly, and don’t overheat it, as this can cause it to expand and become even more difficult to remove.
  3. If the nut still won’t budge, try alternative methods such as using a penetrating oil or a bolt extractor.

Drill the Nut

To get that pesky bolt off, grab a drill and start making a hole in the center of the rusted metal. This will weaken the nut’s hold on the blade and eventually allow you to remove it. Make sure to use the right size drill bit to ensure that you don’t damage the blade or the surrounding area.

If you’re not comfortable using a drill, there are alternative methods you can try. For instance, you can use a chisel or a hammer and screwdriver to loosen the nut. However, this method requires more time and effort, and there’s a higher risk of damaging the blade or the surrounding area.

Regardless of the method you choose, make sure to wear safety goggles and gloves to protect yourself from flying debris and sharp edges.

Replace the Nut and Blade

Now that the old bolt’s been defeated and its hold on the blade has been broken, it’s time to give your mower a new lease on life. Replace the worn blade and secure it with a fresh nut.

First, inspect the blade for any signs of damage or wear. If it’s dull or damaged, take this opportunity to sharpen or replace it. A sharp blade not only cuts the grass more efficiently, but it also promotes healthy grass growth by making clean cuts that reduce stress on the plant.

Next, refer to your mower’s maintenance schedule to ensure that you’re using the correct blade and nut size for your model. Install the new blade and hand-tighten the new nut.

Use a torque wrench to tighten the nut to the manufacturer’s recommended torque specification. This ensures that the blade is securely fastened and operates safely.

Remember to follow the maintenance schedule and inspect the blade and nut regularly to ensure they remain in good condition.


Remember, when dealing with stripped nuts, it’s important to assess the severity of the stripping and gather the right tools. Applying lubricant or penetrating oil can make the process easier, as can using a wrench or pliers. If those methods don’t work, bolt extractors, heat, or drilling may be necessary.

In the future, to prevent a stripped nut from happening again, it’s important to regularly maintain your lawn mower and replace the blade as needed. By following these steps, you can save yourself time, money, and frustration.

So go ahead, give yourself a pat on the back for a job well done and enjoy a well-maintained lawn. Remember, the key to success is persistence, patience, and attention to detail.