If you want a well-groomed lawn, sharp lawn mower blades are essential. Having sharp blades isn’t just important for the maintenance of your lawn mower, it also ensures a clean, precise cut that promotes a healthier lawn. This guide will help you understand the signs of dull blades and how to choose the best tools and techniques.
When do lawn mower blades need sharpening?
Like any tool, lawn mower blades can suffer from wear and tear over time.
Here are some of the main causes of dull blades:
- Hitting rocks, sticks, or other debris while you’re mowing
- Regular use that will wear down the blades over time
- Mowing uneven surfaces
You don’t have to physically check the blades to tell if it’s dull, as there are many signs that will let you know when it’s time to sharpen them:
- Uneven, torn grass tips
- Grass tips that look brown and frayed
- Mowing time has increased
- Lawn mower engine seems to be struggling
It’s important to regularly inspect your lawn and your mower for any of these signs, so that you always have a healthy, green lawn.
How often do lawn mower blades need sharpening?
Every lawn is different, but on average, lawn mower blades need to be sharpened after every 20-25 hours of use. Depending on the size of your yard, how often you choose to mow, and the time it takes you to mow it, however, you may need to adjust accordingly. Properly maintaining your mower blades will lengthen the lifespan of your mower.
Lawn mower blade sharpening equipment
When it’s time to sharpen your lawn mower blades, you will want to make sure you have the right equipment. The equipment you’ll need will depend on how you decide to sharpen the blades.
Equipment needed if sharpening by hand:
Equipment needed if sharpening with an angle grinder:
- Angle grinder
- Safety glasses
- Work gloves
- Ear protection
- Clamp or bench vise
Equipment needed if sharpening with drill-powered blade sharpener:
- Safety glasses
- Work gloves
- Ear protection
- Clamp or bench vise
- Standard drill
- Blade sharpener
If you’re missing any of these tools needed to sharpen your blades, make sure to visit Tractor Supply to find what you need at an affordable price!
Preparing lawn mower blades for sharpening
Before you begin sharpening, it’s important to properly remove and prepare the blades. The first step before removing the blades is to disconnect your lawn mower’s battery or the spark plug to eliminate any risk of accidental starts during the process. You will also want to drain the gas tank to avoid any spills. Once this is done, you are ready to begin.
- The first thing you want to do is make sure you put on work gloves and protective eyewear.
- Lift the mower to a height or turn it on its side allowing easy access to the blades. Secure the mower properly to prevent any accidental movement.
- Identify the bolts or nuts securing the blades to the mower deck.
- Using a wrench or socket set, carefully loosen and remove the fasteners. Make sure to keep track of the order and orientation of washers and nuts for when you reassemble the blades.
- If you have trouble removing the blades, use a block of wood between the blade and the mower deck for leverage.
- Clean the blades and use a wire brush or a rag to remove any grass, dirt, and debris.
- Examine the blades for any signs of wear, cracks, or damage and address any issues before sharpening.
3 Ways to Sharpen Lawn Mower Blades
When it comes to sharpening your lawn mower blades, you have options. Whether you prefer the hands-on precision of a file, the efficiency of a bench grinder, or the ease of a sharpening tool, the choice is yours. These three options allow you to choose the approach based on your comfort level, equipment availability, and the extent of blade maintenance needed.
How to sharpen lawn mower blades by hand
Sharpening lawn mower blades by hand may seem like a traditional approach, but it allows for a precise result with little equipment needed.
- Put on your safety gloves and protective eyewear.
- Secure the blade using a vise or a clamp.
- Using a metal file, press the file firmly against the blade and match the angle of the cutting edge. Sharpen the blade in a single direction, don’t drag the file back and forth.
- File the blade using even, consistent strokes and constant pressure. You should be able to feel the file teeth on the blade. If you don’t, apply more pressure until you do.
- Once you’ve removed any nicks and evened out rough spots on one side, release the blade from the vise.
- Turn the blade and do the other side.
Sharpening by hand is a precise, hands-on approach to maintaining the quality of your mower blade.
How to sharpen lawn mower blades with an angle grinder
If you’re looking for a faster, more efficient method to sharpen your lawn mower blades, or if you have significant blade wear, using an angle grinder may be your best bet. With an angle grinder, you will be able to sharpen your blade in a matter of minutes, and it can remove even the heaviest of damage.
- First, put on your safety glasses, work gloves, and ear protection.
- Secure your blade using a vise or a clamp.
- Ensure the angle grinder is set to a suitable speed.
- Align the grinder with the cutting edge of your blade, maintaining the blade's original angle.
- Apply smooth, even strokes across the blade.
- Remove any nicks or dull spots.
- Release the blade from the vise.
- Turn the blade and do the other side.
Using an angle grinder is a quick and efficient way to rejuvenate your lawn mower blades.
How to sharpen lawn mower blades with a drill-powered blade sharpener
Using a drill-powered blade sharpener is a smaller, more affordable tool to use, if you’d rather not sharpen by hand and if you don’t want an angle grinder taking up space in your garage. The stone of the drill bit is designed to auto-adjust to the edge of your lawn mower blade, making sharpening easy with minimal effort and fewer mistakes.
- Put on your safety glasses, work gloves, and ear protection.
- Secure your blade using a vise or a clamp.
- Connect the blade sharpener to the drill according to the manufacturer's instructions.
- Turn the drill on by pulling the trigger.
- Move the sharpener along the blade edge, ensuring even and controlled sharpening.
- After about four or five passes, test the blade, it should be as sharp as a butter knife.
- Release the blade from the vise.
- Turn the blade and do the other side.
Sharpening with a drill-powered blade sharpener offers a simple and efficient method for those who already own a power drill.
Check your blade balance
After sharpening, you will want to check the balance of your blade. A balanced blade reduces wear on the lawn mower engine and ensures an even cut across your lawn, allowing for a smoother mow. More importantly, an unbalanced blade can cause your mower to vibrate excessively and even potentially damage it. Luckily, checking the balance of your blade is easy.
- Using a nail, screwdriver or balancing tool, suspend your blade horizontally.
- A well-balanced blade will hang level. If one side dips, it means your blade has an imbalance.
- If you observe an imbalance, add small, equal-weighted adjustments to the heavier side.
- Suspend the blade again to make sure it hangs level after the adjustments.
By taking a few extra moments to check and correct the balance, you contribute to a smoother mowing experience and maintain the health of your mower and the quality of your lawn.
How to refit lawn mower blades
Now that your blades are sharpened and balanced, you need to refit them to your lawn mower before your next trim.
- Locate the bolts or nuts that secure the blades to the mower deck.
- Make sure the blades are correctly aligned and positioned, with the angled side facing up.
- Put the blade back onto the bolt.
- Using a wrench or socket set, securely tighten the bolts or nuts.
- Reconnect your battery or spark plug.
- Refill the gas tank.
- Start your mower to make sure everything is running smoothly.
Refitting your lawn mower blades is just as straightforward as removing them, and after you do it once, you’ll have no issues each time you have to re-sharpen your blades.
Maintaining your lawn mower
Blade sharpening is a crucial part of lawn mower care, but it’s not the only one. To keep your mower in great condition, you should be performing regular maintenance tasks, like checking and changing the oil when needed, inspecting the spark plugs, cleaning or replacing air filters, and checking your tire pressure.
As you embrace these lawn mower maintenance practices, you not only extend the life of your equipment but also guarantee an efficient mowing experience, so that having a beautifully manicured lawn is a breeze!