How to Remove a Lawnmower Blade (The Right Way)

If your lawnmower isn’t cutting like it used to or is leaving behind uneven, ragged grass, it’s probably time to remove or replace the blade. While this might sound like a tricky task, removing a lawnmower blade is simpler than you think when armed with the right tools and know-how.

In this guide, we’ll walk you through the process step-by-step – covering everything from the essential tools to frequently asked questions about replacing a lawnmower blade. By the end, you’ll have the confidence to tackle the task with ease. Let’s get started!

Before diving in, make sure you have the right equipment on hand. The last thing you want is to start the job only to find you’re missing a critical tool. Here’s what you’ll need:

• Socket wrench (most mowers require a 5/8” or 9/16” socket size, but check your manual!)
• Gloves (safety first—blades are sharp!)
• Block of wood or clamp (to prevent the blade from spinning)
• WD-40 or penetrating oil (optional but handy for loosening stubborn bolts)
• Towel or rag (to wipe down grease or grass buildup)

Removing a lawnmower blade involves working near the cutting deck, so it’s crucial to ensure everything is safe before you start. Here’s how:

1. Disconnect the spark plug – This prevents the mower from accidentally starting while you’re working.
2. Empty the fuel tank – Tip the mower on its side without spilling petrol by either emptying the tank or sealing it tightly to avoid leaks.
3. Wear gloves – Protect your hands from sharp edges.

To access the blade, you’ll need to tilt the mower carefully. Here’s how to do it right:

• Tip the mower correctly – Always tilt the mower with the air filter facing up to avoid oil leaks into the engine.
• Stabilise the blade – Use a block of wood to wedge between the blade and the mower deck, holding it securely in place. This stops the blade from spinning as you loosen the bolt.

This is one of the most common questions we get; here’s the answer:

• Most lawnmower blade nuts are reverse thread. This means you’ll need to turn the bolt clockwise to loosen it (unlike standard bolts). Why reverse thread? It ensures that the blade doesn’t loosen during operation.

Tip: If the bolt won’t budge, apply some WD-40 or penetrating oil and let it sit for a few minutes to loosen the rust or debris.

With the bolt loosened, carefully remove it and slide off the blade. Take note of the blade’s orientation—you’ll need to install the new blade or reattach the old one in the exact same position. (Hint: The sharpened edge should face the direction of rotation!)

Once the blade is sharpened or replaced, it’s time to reattach it:

1. Align the blade – Position the blade in the same direction it was originally installed.
2. Tighten the bolt – Turn the bolt anti-clockwise to secure the blade. Be sure to tighten it firmly but avoid over-tightening, which could damage the bolt or mower.
3. Reconnect the spark plug – After reattaching the blade, safely reconnect the spark plug.

Don't forget your spare blade for your VonHaus lawnmower! 

Q) How do I lift a mower to change the blades?
A) If you’re working with a push mower, tipping it on its side as described above is sufficient. For riding mowers, you may need a lawnmower lift or jack to safely access the blades. Always consult your mower’s manual for guidance.

Q) What wrench do I need to change a lawnmower blade?
A) A socket wrench is typically required, with common sizes being 5/8” or 9/16”. However, your mower’s manual will specify the exact size needed.

Q) How often should I change or sharpen my lawnmower blade?
A) Sharpen your blade every 20-25 hours of use, and replace it if it becomes damaged, bent, or excessively worn.

Wrapping Up 

Removing a lawnmower blade doesn’t have to be a hassle. With the right tools, proper safety precautions, and a little patience, you’ll have your mower back in top shape in no time. Whether you’re replacing a dull blade or giving it a fresh sharpening, the steps we’ve outlined will help keep your mower cutting cleanly – and your lawn looking its absolute best. So, grab your tools, get to work, and give your garden the care it deserves. Your grass (and neighbours) will thank you!