Do Brand New Lawn Mower Blades Need To Be Sharpened?

This is a super common question that people have when it comes to their lawn mowers and changing the blade. Do brand new lawn mower blades need to be sharpened or can I just attach them and get mowing? Obviously the condition of the blade is very important in terms of the quality of the cut that you’re able to achieve, so you want to be absolutely sure that everything is set up correctly before you get down to business.

Getting Straight to the Point: To Sharpen a New Lawn Mower Blade or Not?

No, it’s not necessary to sharpen brand new lawn mower blades. You can simply remove your new blade from its packaging, remove the old blade carefully from your mower, and then attach the new one. There will be a short breaking-in period, as we’ll explain below, but there are no extra steps or additional preparation required.

Why Do Some People Think that Sharpening a New Mower Blade is Necessary?

I can understand why this question confuses so many people. After all, why the hell would you need to essentially perform maintenance on an item that is brand new? Shouldn’t it be ready to go right out of the box?

The main reason that some people believe that new blades should be sharpened before use is due to the powder-coated paint finish that is applied to most replacement blades by the manufacturer. This finish is particularly thick around the blade’s cutting edge and to the touch, it can make it feel like it’s dull. And we all know that a dull blade isn’t good for your grass!

But there are a few reasons for the presence of this paint finish:

• It Protects You From Injury – When installing your new mower blade, you’re obviously going to have to handle it. The paint finish dulls the cutting edge and makes it much more unlikely that you’ll cut yourself when installing it, even if you don’t wear any protective gloves.
• It Protects the Blade from Damage – I’m clumsy as hell and if you’re anything like me, you might drop, catch or scrape your new blade on a hard surface before you’ve even fitted it. And if you’re unlucky this could damage the cutting edge before you step foot onto your lawn. The protective paint finish also serves to protect the blade from this type of damage.
• It Prevents Issues with Rust – Rust is not a problem you want to have with any part of your mower, and especially not with the blade. This finish gives your blade some added protection from moisture.

However, even though this protective finish makes the blade feel dull, you don’t need to remove it. We’ll explain why below.

Why Don’t You Need to Remove The Protective Finish that Makes Your Blade Feel Dull?

Grass is more abrasive than you probably realize and the protective layer that coats your new blade is not designed to be long lasting. In fact, after a brief “breaking in” period, you’ll notice that the paint starts to come off. After 30 minutes or so of mowing, if you take a look at the blade, you’ll see that the protective layer around the blade’s edge has worn away and as a result, the edge is sharper and perfect for cutting grass (remember mower blades only need to be butter-knife sharp and not carving knife sharp).

The exact amount of time it takes to complete this “breaking-in” period will depend a little bit on the type of grass that you have, with some varieties being much thicker and more abrasive, meaning the paint gets worn off quicker. For softer grass varieties it may take a bit longer. But the main thing to be aware of is that this layer of paint will wear away and reveal a blade edge that is perfectly optimized for mowing your lawn.

Potential Negative Impacts of Sharpening a New Lawn Mower Blade

The fact that brand new lawn mower blades don’t need to be sharpened not only saves you time and effort, but it also saves you potential headaches too. This is because sharpening a new blade can potentially cause it to become unbalanced and compromise its integrity.

Unbalanced blades in particular can have a whole host of knock-on effects, causing lots of vibration (not a pleasant experience when you’re mowing), and place your blade shaft, spindle and engine under greater stress, likely shortening their lifespans.

So next time you buy a replacement mower blade, all you need to do is install it and get on with mowing. End of story.