How often should I change my robot mower blades?
How Often Should I Change My Robot Mower Blades?
Robot mowers make lawn care simple, but sharp blades are the key to getting that clean, tidy finish every day. One of the questions I’m asked most often is “How often should I change the blades on my robot mower?”
The short answer is that it depends on how often/how long the mower runs and what it’s cutting through.
The longer answer — and the one that protects your mower and your lawn — is below.
In this blog, I’ll walk you through the signs of blade wear, how long blades usually last, and what you’ll see in the video that goes with this post. The mower featured in the video is a Kress KR236, but the same principles apply to all major brands.
What Robot Mower Blades Are Made Of
Most modern robotic mowers use stainless steel blades.
They’re strong, durable and stay sharp for a long time, but they still wear down with use.
Stainless blades typically show wear through:
- Dulling
- Chipping
- Worn corners
- Bent edges
- Enlarged mounting holes
Stainless steel rarely rusts unless the mower sits unused for weeks.
How Long Do Robot Mower Blades Last?
Residential properties
On an average suburban lawn, blades usually last around eight weeks.
Commercial properties
Commercial sites with longer runtime or tougher turf wear blades out faster — around four weeks.
Golf courses
Golf courses typically change blades every 7–10 days to keep a razor-sharp cut on fast-growing fairways and roughs.
What Causes Blades to Wear Out Faster?
Some lawns are simply tougher on blades. The biggest blade killers are:
- Sticks and bark
- Rocks or gravel near edges
- Sandy soils
- High mowing frequency
- Tougher grass species
Anything the mower hits or grinds through will significantly speed up wear not only of the blades but the screws as well.
How to Know When It’s Time to Change Your Robot Mower Blades
This is the core of the video that accompanies this blog.
Here are the signs I look for when checking blades:
Chips in the blade edge
Even small chips reduce cut quality.
Worn or rounded corners
A sharp blade lifts and slices the grass cleanly. A rounded blade tears the leaf instead.
Bent blades
If the blade has hit something solid, it may bend slightly. Bent blades lead to uneven cutting height and unbalanced discs.
Enlarged or stretched mounting holes
If the hole is worn, the blade won’t sit correctly and can become unstable at high speed.
Uneven or rough cut on your lawn
Jagged grass tips mean your mower is tearing the grass rather than slicing it.
This leads to:
- Browning of the leaf tips
- More stress on the grass
- Extra load on the cutting motor
If your lawn suddenly looks rougher than usual, the blades are usually the reason.
Should You Change the Screws Too?
Yes.
Every reputable replacement blade kit includes
Should You Change the Screws Too?
Yes.
Every reputable replacement blade kit includes new screws.
Use them.
Old screws can rust, wear or stretch slightly over time.
Fresh screws ensure the blade sits perfectly and stays secure.
Can You Change Robot Mower Blades Yourself?
Absolutely.
Blade changes are designed for end users.
Most brands, including the Kress KR236 in the video, require only:
- A Phillips-head screwdriver
- A few minutes of your time
- A safe place to flip the mower over or place it on its side
Important safety tip
Wear gloves.
New blades are incredibly sharp — like tiny scalpels — and can easily cut fingers and palms.
Are All Robot Mower Blades the Same?
They may look similar, but they’re not interchangeable.
Each brand has slight differences in:
- Blade length
- Thickness
- Screw hole size
- Screw thread type
Using the wrong blades or screws can damage your mower or cause the blade to come loose. Always replace blades with the correct type for your mower.
Genuine vs aftermarket blades
Genuine blades are a cheap investment in:
- Better cut quality
- Longer motor life
- Safety
Aftermarket blades often cut corners on steel quality or screw hardness.
I recommend sticking to genuine blades. You've invested your hard earned money in a robot mower, why cut corners to save a couple of dollars?
Where to Buy Replacement Robot Mower Blades
For convenience and correct fitment, you can buy the right blade kits here:
Final Thoughts: Change Blades Before You See a Problem
Replacing blades is simple, cheap and takes just a few minutes.
Doing it regularly:
- Protects your lawn
- Reduces stress on the mower
- Improves cut quality
- Keeps the mower running efficiently
If you follow the timing guides above and check your blades when you clean the mower, you’ll never fall behind.