What To Do If Your Lawn Mower Blades Are Bent?

While most people won't look at their lawn mower blades before they start cutting the grass, if you accidentally hit a rock or large branch, you could end up with bent blades. When this happens, you may notice that your mower starts behaving differently than it normally does. For example, you may notice a grinding noise, or you might just notice that it's not cutting the way you're used to. These are good indicators the blades may have been damaged and could possibly be bent. The first thing you should do if you suspect bent blades is to stop mowing, so that you don't damage your mower's engine.

Depending on whether you have a gas-powered, battery-operated, or an electric mower, take the necessary precautions, like removing the spark plug or battery, and then lay the unit on its side so that you can inspect the blade. You may have to actually take it off to look at it more closely. If you do, make sure to wear heavy-duty gloves because the blade edges will be sharp. Also remember that the nut may have a left-handed thread, in which case you'll have to turn it clockwise to remove it.

While you may know how to sharpen your mower blades efficiently, unless you happen to have a machine shop in your garage, it's best not to attempt to straighten a bent blade yourself. A much better option is just to buy a new one to replace the one that's damaged.

It's a good idea to take a photo first before removing the blade from your mower; and then take the blade and the nut with you when you head to your local Home Depot or Lowe's. You will also want to note the make and model of your mower. You might even want to check your owner's manual, which will specify the exact size blade that you need.

Depending on the type of mower you have, a new blade could set you back between $20 and $50. That's far better than the cost of having to replace the mower itself if you do attempt to straighten the blade and fail to get it right to specifications. When fitting your new blade, make sure you do it correctly. For instance, one big mistake would be to install the lawn mower blade upside down (if you do, the curved part of the blade — aka the wings, fins, or sail — will make contact with the ground instead, resulting in a choppy, uneven cut).

To avoid the issue of bent blades in the first place, always make sure to inspect your lawn before you run the mower over it. Pick up any objects that might be hidden, and move any obstacles, such as that rock or large branch, out of the way. 

The other thing you want to do is avoid sharpening your blades too much because this will weaken them and make them more prone to damage. For that reason, familiarize yourself with how sharp your lawn mower blades should be, and stick to that.