Learning how to change a lawn mower blade is something everyone with a mower needs to know. Everyone needs their lawn mower to cut the grass when it gets too tall. Unfortunately, over time, any blade will get dull and will start to cut less. It’s recommended that you do not go more than two years without sharpening the blade of your lawnmower. You can also save money if you sharpen the blades yourself.

If you choose to pay someone trained to remove your blade before sharpening it, you could end up paying more than three times what you normally would pay.

It’s important to the health of your lawn to keep your blade sharp and in good working condition. A dull blade will strain the motor of your lawn mower which means you will drain the battery or burn more gas depending on whether your lawnmower is electric or gas-powered.

You may need to sharpen your blade more than what is generally recommended depending on the type of grass that is on your lawn. If you’re not sure, mow your lawn then look over your grass. If the tips of your grass are brown, or you have a lot of split ends in your lawn, those are signs that the blade needs to be sharpened.

More signs that you will need to change a blade is if the blade is bent. This happens if rocks or other rough surfaces were on the lawn when it was mowed. If you continue to use a blade while it’s bent, you could cause more damage to the other parts of your lawn mower over time.

Even if you are successful in sharpening your lawn mower blade, you can only sharpen it so many times before that blade remains dull regardless of what you do.

If you are not sure how to change a lawnmower blade, then we will go over the steps so you remove the blade safely without hurting yourself or wrecking your lawnmower. It is recommended that if you have a gas-powered lawn mower, you change the blade when the lawnmower is empty or after you have removed the gas safely.

How to Change a Lawn Mower Blade

Ensure Mower Won’t Start

You want to make sure that your lawnmower can’t turn on while you are changing the blade. We already mentioned removing the gas if your lawnmower is gas-powered.

  • If your lawn mower is electric, it is recommended to take out the battery before doing anything else. Once you have done this, then you want to put the lawnmower on its side.
  • If your lawnmower is gas-powered, you want the air filter on top so the filter doesn’t get soaked by oil. If you fail to do this, then you may need to replace the filter as well as your blade.

Use Protective Gear

You don’t want to risk your blade cutting you while you remove it so you want to wear thick gloves to prevent this. Then use a block or clamp to keep the blade in place. After this has been done, unscrew the fasteners that are keeping the blade in place. The number of fasteners may vary but usually, there is only one or two.

Keep the Instruction Manual Handy

After you have removed the blade, you will have to remember how everything is supposed to go after you sharpen your blade.

Bonus tip: Use your smartphone to take plenty of pictures at various stages. These images will provide a reference for things like:

  • Blade position
  • Where screws and bolts go
  • Drive and deck belt orientation

If you still have the instruction manual for your lawnmower, then that will have a picture of how everything goes back correctly. If you do not have the manual, then take a picture so you can reference it when it is time to put the blade back.

Sharpen the Blade

If you have a metal file or a bench grinder, then you can sharpen the blade yourself. If you don’t have what is needed to sharpen your lawn mower blade, then you will have to take the blade to a professional who can sharpen it for you.

Re-Attach the Blade

After your blade has been sharpened by you or a professional, you want to replace the blade according to the instruction manual or picture that you took earlier.

  • Make sure the edge that cuts is going in the right direction. The wings of the blade should be pointing up and if there is writing on the side of a blade, that side should be facing down.

  • If a washer is included with the bolt of the blade, then the curved side will be facing the blade.

  • Once the blade is back in place and you are ready to make the bolts tight again, you want to put your gloves on.

  • Put back the clamp or block you had in place when you loosened the bolts before you tighten the bolts.

Depending on who you ask, there might be different opinions on what wrench you should use to tighten the bolts. There is a possibility of cracking the bolts or the blade coming loose if the bolts aren’t tightened correctly.

Before You Get Back to Mowing

Before putting your lawnmower in the upright position, you may want to clean out the deck then use silicone spray if you happen to have any. This would help your lawn mower perform at its best while not draining the battery or burning more gas than it’s needed.

It is possible to change your lawnmower blades and save money if you have the required tools to sharpen your lawn mower blade yourself.

If you do choose to sharpen your lawn mower blade, remember that there is nothing more important than safety. Remember to take all the necessary precautions and follow the steps we went over to successfully change your lawnmower blade.