Green's Lawncare & Property Services Residential Lawn Care and Maintenance

How to sharpen lawn mower blades

If you are like many homeowners in the Meridian-Kessler and Broad Ripple area, you more than likely own a push mower.  The yards are smaller and you can efficiently mow the entire property in under 30 minutes using a small 21- or 22-inch push or self-propelled mower.  Some of the bigger properties as you move into the Meridian Hills and Nora neighborhoods require a riding lawn mower, but when it comes to sharpening your lawn mower blades it is all the same.  You may be asking, why do I even need to sharpen the blade(s) on my lawn mower or how do you do it?  These questions will be answered below.

Why do I need to sharpen my lawn mower blades?

For a clean cut, the mower blades must be sharp.  When the blade(s) gets dull, it will tear the blade of grass rather than cut it.  When the blade of grass is torn, it will have a grayish brownish color on the tip off the grass blade.  This will make your lawn appear to be browning, when the lawn could in factor be thriving.  The easiest thing to do is to keep an extra blade on hand.  This way you can swap out the dull blade for a sharp one and continue mowing; you won’t lose any time.

grass blade, dull mower blade
This is what grass looks like when it has been cut with a dull lawn mower blade.

How do I take the blade off my mower?

Often times you need to turn the push mower on it’s side (oil dip stick side towards the ground) so you have access to the underside of the mowing deck.  If you have a riding mower, you will need a car jack to lift it in the air.  Make sure there is not grass stuck under the deck.  If there is grass under the deck scrap it clean first.  You should scrap your deck after each mow.  You will probably need a block of wood to keep the blade from spinning.  Once you have the block of wood wedged in there, use a socket wrench to remove the bolt holding the lawn mower blade.  Some penetrating oil and a breaker bar may be needed if you haven’t done this in a long time.  This will save you money.  When a repair shop has to take the blade off, they will charge you extra.

Sharpen the lawn mower blade?

Below you will see a demonstration of how to sharpen the blade.  You want to create a perfect 30 degree cutting angle.  We do that by using a specialty blade sharpener.   We sharpen hundreds of blades a year so it made since from a professional stand point to invest in a blade sharpener.  However, you probably don’t have one and it would be crazy for you to go buy one.  Often times, homeowners will use a file or an angle grinder to put a sharp edge on the blade.  If you are not wanting to do the work, a lawn mower repair shop will usually do it for around $10 per blade.

lawn mower blade, sharpening
Sharpening a lawn mower blade


Balancing the blade…

Balancing a lawn mower blade is very important.  The engine is spinning at 3000+ RPM and it must have a balance blade or you could destroy the bears, spindle, etc.  You can buy a fairly inexpensive blade balancer on Amazon or a local home improvement store.  If one side is heavier than the other, then grind a little more off that side until they are equal weight.  Once they are equal weight, you can then put the blade back on the mower.


There you have it!  You just sharpen your first lawn mower blade.   If it fairly easy process, if you have the correct tools to do the job.  Your lawn will thank you for having an extra blade sitting around the house to swap out when the current one dulls out.  Professionally, we swap blades every 8-12 hours of cutting time.  That means daily.  We have 5 sets of blades for each mower and sharpen them all when they get dull.  Hopefully this has article has helped you understand why and how to sharpen a lawn mower blade.