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How to Sharpen Lawn Mower Blades

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If you own a lawn mower, at some point you're going to need to sharpen the blades. Your lawn mower takes a beating, and the blades are getting the worst of the assault. At a minimum of once a year, you should thoroughly inspect your blades for damage and dullness, but regular checking is best. If they're damaged, you should replace them before mowing again, however, if they're dull, a good sharpening will significantly improve your mowers performance.

Mowing your lawn when the blades are dull can cause a ragged cut. Your grass will turn brown and be susceptible to disease. Your mower requires sharp blades in order to deliver a great looking and healthy lawn. Sharpening lawn mower blades isn't a difficult task and you'll be pleasantly surprised at how much nicer your lawn looks. This article will show you how to sharpen your lawn mower blades.  

When to Sharpen Lawn Mower Blades

Visually inspecting your blades regularly is always a good idea, but also pay attention to how your grass looks after mowing. Here are a few signs that indicate it might be time:

  • After mowing the height of the grass is uneven
  • The grass blade tips looked frayed, and a short time later they turn brown
  • The grass blades look tattered and torn, instead of a clean, even cut
  • When inspecting the mower blades, you notice the blades have nicks or dents, or they've been damaged by a rock or concrete
Socket Wrench

How to Remove your Lawn Mower Blades

Before sharpening your lawn mower blades, you first need to remove them from the mower. Before starting, always wear gloves and protective eye gear, then disconnect the power source. If your mower is gas, remove the spark plug wire, if its electric, disconnect the power cord or remove the battery.

  • For gas mowers, you'll need to drain the gas tank
  • Turn the mower on its side with the air filter and carburetor facing upwards
  • Use a wrench to loosen and remove the nut that attaches the mower blade to the deck. Pay attention to how the blade is positioned to prevent putting it upside down when you're reattaching it later. Be careful not to let the blade fall to the ground
  • Clean the blades with a microfiber cloth or a dry rag. In some cases, it may necessary to use a brush or penetrating oil to clean the blade

Preparing the Blade for Sharpening

After you've removed and cleaned your lawn mower blades, it's time to get ready to sharpen them. On opposite sides of the blade is a 3 to 4-inch long cutting edge. 

Clamp the blade onto a worktable or into a vise so that one of the cutting edges (chiseled side) is facing up. Take a close look at the blade and check for cracks or dents. If you see any, you'll need to replace the mower blade with a new one. Unfortunately, a damaged blade can not be sharpened.

There are several methods to sharpen lawn mower blades. It can be done by hand, punches and chisels, or with a drill or a bench grinder.

Some people like to sharpen their lawn mower blades to a razor sharp edge, but we recommend they only be butter knife sharp. When blades are sharpened to a razor edge, they tend to develop nicks when they come in contact with sticks, this shortens the service life of the blade,

Clipping grass with scissors

How to Sharpen Lawn Mower Blades by Hand

Many people prefer sharpening their lawn mower blades by hand because they have more control. Here's how to do it:

  • Follow the contours of the blade with a flat file, in single downward strokes 
  • As you start to see the shiny new metal, try to balance the filing across the full cutting surface of the blade
  • Once the blade is sharpened, drag a sharpening stone over the edge to slightly dull it down. This will help protect your blade from nicking when it hits a stick
  • Turn the blade in your vice so you can sharpen the other side.
  • When sharpening the other side, you'll want to try to take the same amount of material off. This will keep your blades balanced.

We recommend hanging the blade, using the center hole from a nail or hook to check that it is properly balanced. If it leans to one side, you can take a little more metal from that side.

Watch the Video

How to Sharpen Blades with a Drill-Powered Sharpener

Another way to sharpen your lawn mower blades is to use a drill-powered sharpener. The one available from Funvolution is specifically designed for sharpening mower blades and will give you the proper angle automatically.

Funvolution Lawn Mower Blade Sharpener Universal for Any Power Drill/Hand Drill,Mower Blade Sharpener for Lawn Mower & Mower Blades

Funvolution Lawn Mower Blade Sharpener

When sharpening lawn mower blades, you should always wear gloves and protective eye gear. We highly recommend using a vice to secure your blades while sharpening.

Here's how to use the Funvolution drill-powered sharpener:

  • Place the blade between the grinding stone and the plastic disk
  • Run your drill back and forth over the edge of the blade until sharp
  • Repeat with the other side
  • Hang the blade on a nail or hook to check for balance

Watch the Video

How to Sharpen Lawn Mower Blades with an Angle Grinder

Using an angle grinder is another way to sharpen your lawn mower blades. When working with an angle grinder, you should always wear gloves and safety googles, and we highly recommend wearing long sleeves as well.

Here's what to do:

  • Secure your mower blades in a vice grip
  • With a 40-grit flap disk on your angle grinder, begin grinding by following the same angle as the blade 
  • Start at the center of the blade and move your grinder to the end
  • To keep the blade balanced, count the number of strokes, and then match it when you are working on the other blade

Watch the Video

When to Purchase Replacement Lawn Mower Blades

It's a good practice to visually inspect your blades on a regular basis. If you notice the blades have any nicks or dents, they should be replaced and not sharpened. Also replace, if the blades are heavily damaged from an impact with a rock or concrete. In addition, check the thickness of the mower blade and look for blade erosion as this can happen with use over a period of time.

Regular sharpening of your blades will extend their service life, but if you're not interested in breaking out the file, then you should replace the blades every year. It's always a good idea to check your mower's owners manual for the manufacturers recommendation.

Buying New Blades

The good news is that lawn mower blades are relatively inexpensive. Oregon lawn mower blades are among the most popular because they are high quality and are used by some of the top manufacturers. Oregon's Gator Blades are made for mulching with a riding mower, and create a high amount of air lift inside the cutting deck.

If you're looking for quality mulching blades, then you should take a look at Oregon's G5 Gator Blades, or their Oregon G3 Gator Blades.

If you need Husqvarna lawn mower blades, or blades for any other walk-behind mower, then you'll find no shortage of options on the market. This Husqvarna Premium Blade Replacement is suitable for 22" mowers. It's a standard straight edge blade for basic cuts.

If you need a mulching blade for a 22" lawn mower, then you might want to check out the Maxpower Universal Gold Metal Mulching Lawn Mower Blade. MaxPower is a trusted OEM manufacturer, and their blade quality easily meets, and frequently exceeds, factory installed mower blades on Craftsman, John Deere, and other top name mowers.

Last update on 2022-04-29 / Affiliate links / Images from Amazon Product Advertising API

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