Care and upkeep of a lawnmower is an essential component, especially when it comes to the blade. You have to ensure it retains its sharpness so that it cuts your lawn evenly every time. Whether you do it yourself or you have your local hardware store do it, the blade must have proper sharpening.
But can a mower blade be too sharp? While it’s important that the blade is sharp, it shouldn’t be razor sharp. This means that when you graze your finger over the edge, it shouldn’t cut you. If a blade ends up being too sharp, it will get dull far more quickly and will need more sharpening, thereby shortening the blade’s lifespan.
What Is the Proper Sharpness for Lawnmower Blades?
How sharp a blade should be will impinge on the nature of the grass along with the type of terrain. If you’re often going over soft grass and weeds, then sharpen the blades at a very low angle. But, you may want them to stay a little blunt when using a mower over an area that’s rough or woody.
However, in most cases, the mower’s blade should always sharpen at a 40° angle and never less than 30°. Anything else below that is going to be far too sharp and it shouldn’t change from the original bevel.
You want the blade to be sharper than a butter knife but not nearly as sharp as a razor. A happy medium between these ranges of sharpness is most ideal.
What Causes a Mower Blade to Lose Its Sharpness?
There are many things that can affect a mower blade’s sharpness. The most obvious thing that will greatly influence sharpness is how many stones or sticks with which the blade comes into contact. These are the top culprits for dulling a mower blade.
However, another cause for a blunted blade is the frequency in which you sharpen it. If you don’t sharpen it enough and let it sit dull while continuing using it that way, the blade will be more difficult to sharpen. But, if you sharpen it too much or if the blade is too sharp, it will make the blade get duller faster.
Also, if you don’t sharpen it right, the irregularity of the shape will make for an uneven beveled edge. Both frequency and irregularity are culprits in forcing blades to lose their sharpness faster than you want.
But how fast they become blunt will also depend on how thick or thin the blade is. Thinner blades tend to get duller faster and require more sharpening than thick ones. This is also true for how low the blade sits in relationship to the ground. The blade will become dull quickly if it’s too close and becomes more vulnerable to things like stones and sticks.
Does Blade Sharpness Matter or Make a Difference?
The sharpness of a lawnmower’s blade is the most important component to this type of machine. Therefore, its sharpness matters very much and it can make a difference. It’s the fine line between a well-manicured lawn or a shabby looking one.
For instance, when the grass is tall and bushy at the start of spring, only a sharp blade will do the job. This will not only cut the grass with ease but it will also take the strain off of your mower.
What’s more, if a mower’s blade is dull, it will tear the edges on the grass. This will create a rugged, uneven look to the lawn and it will adversely affect the overall health of your lawn. Torn grass will also become dry, leaving behind crispy brown tips. This sets the stage for your grass to sustain diseases and pests.
Can You Do Anything about a Blade that’s too Sharp?
Unfortunately, there’s nothing you can do in the event you end up sharpening the blade too much. You will have to live with it and cut your grass until they become dull again. It’s going to be a matter of paying attention next time so that you don’t over-sharpen it.
That said, when you do mow, you could set the machine a little lower to the ground or let the blades cut something a little more rugged. This will bring down the sharpness somewhat. But, you will have to pay attention to the blade because you’re messing with its lifespan this way.
How Often Should You Sharpen a Mower Blade?
Ensure that you’re sharpening your mower blade about two to four times each year. This translates loosely to about every eight or nine mowing sessions. Also, don’t sharpen the mower blade while it’s sitting in the machine. You will have to remove it first.
However, there are some people who say you should sharpen mower blades after ever 20 to 25 hours of use. But, it’s not about time span, it’s more about wear-and-tear of the blade itself.
How Do You Keep a Mower Blade Sharp?
The best way to extend the sharpness of a lawnmower blade is by sharpening it correctly and cleaning off the blade after each use. Also, checking the blade before and after each mowing session will allow you to catch dullness before it has a chance to manifest.
Being meticulous about checking the blade between sessions will also allow you to see if there’s any damage from things like rocks, stones, pebbles and sticks.
What If You Don’t Want to Sharpen the Mower Blade Yourself?
Sharpening a mower blade is pretty simple once you learn how. There are many videos and instructional articles available all over the internet. However, if you’re not comfortable doing it or don’t have the right equipment for it, you can take it to your local home improvement center or hardware store.
They will have everything you need to get it done right and in a timely fashion. It’s not very expensive either, it costs around $10 to $15 depending on where you go.
Hi, I’m John Stephens, chief editor and writer for Totalgardener.com. I’ve been gardening and raising animals for over 15 years starting with a small backyard plot in Northern Virginia where I grew corn, potatoes, squash, and using a high mulch technique called the Ruth Stout Method. I also raised ducks and small mammals for meat and eggs in a movable pen similar to the ones used by Joel Salatin. I later moved to Colorado where I experimented with growing greens using aquaponics inside. I eventually added a microgreens setup and home sprouting operation. I’m excited to share everything I’ve learned plus more from the other local gardening and animal raising experts I know.