Robot and Remote Mower Blades: Sharpen, Replace or Self-Sharpening?

Last updated: November 2026

Mower blades dull with use, and dull blades tear grass instead of cutting it, leaving ragged, brown tips. Small razor-style robot blades are usually replaced, not sharpened. Larger bar blades, like those on a remote control mower, can often be sharpened if they are not cracked or badly bent, but must stay balanced. Check blades every few weeks in season, replace them when they are nicked, bent or worn, and always switch the mower off and lock it before you touch them.

Blade questions fill autocomplete: can robot mower blades be sharpened, how long do they last, how often should you change them. Here are the answers for the main blade types.

How do you know blades are dull?

• Torn grass tips that turn white or brown a day after mowing.
• Uneven cut, with strips of taller grass.
• More noise or vibration than usual.
• Shorter runtime on battery mowers, because dull blades take more power.
• Visible nicks, chips or a rounded edge when you inspect them.

What types of blades are there?

What blades does the Mowrator S1 use?

Mowrator sells several blade sets for the S1, each in packs of three:

• Self-Sharpening Mowing Blades: 40MnB steel with a wear-resistant coating, designed to keep an edge longer between sharpening, per Mowrator.
• Mulching Blades: 40MnB steel, dual-stage shredding, and 931 CFM of upward airflow to pick up leaves, per Mowrator.
• High-Lift Blades and Self-Sharpening High-Lift Blades: for lifting clippings into the bag.

Mowrator treats blades as consumable parts that can be exchanged within 30 days if not damaged by misuse.

What about Yarbo blades?

The Yarbo Lawn Mower Pro uses two 300 W cutting motors with a 20-inch cutting width, per Yarbo. Check the blades at the start of the season and every few weeks after, and replace them following Yarbo's manual. Ask us for the right replacement part for your module.

How often should you replace or sharpen blades?

It depends on hours, grass type, sand in the soil, and what the mower hits. As a guide:

• Check every few weeks in the mowing season.
• Small robot razor blades: many owners replace them every month or two of regular use.
• Bar blades: sharpen when the edge is rounded, often once or twice a season, and replace when cracked, bent or worn thin.
• After hitting a stone or root: inspect right away.

How do you sharpen a bar blade safely?

1. Switch the mower off, remove the battery or use the maker's lock, and wear cut-resistant gloves.
2. Mark the blade so you put it back the right way up.
3. Remove it with the right tool.
4. Clamp it in a vise and file or grind along the original angle, removing only enough to restore the edge.
5. Balance it on a blade balancer or nail. An unbalanced blade causes vibration and wears bearings.
6. Refit it to the maker's torque, right side up.

If you are not comfortable doing this, replace blades instead. A fresh set is not expensive compared with the mower.

How do you clean blades and the deck?

Wet clippings stick under the deck and reduce airflow, which hurts the cut and the leaf pickup. Clean the deck with a plastic scraper or brush when the mower is off and the battery removed. Do not spray water into motors or electronics. Mowrator's deck is deep-drawn steel, per Mowrator, which is easier to scrape clean than a rough surface.

Are all mower blades the same?

No. Blades are made for a specific mower's length, mounting, center hole and rotation. Using the wrong blade can damage the mower or throw debris. Buy blades listed for your exact model.

Does blade type change the cut?

Yes. Mulching blades cut clippings and leaves finer so they drop back into the grass. High-lift blades create more lift to throw clippings into a bag. Standard blades sit between the two. Many owners switch to mulching blades in fall; see leaf mulcher vs mulching mower.

How should you store blades?

Keep spare blades dry and lightly oiled to stop rust, in their packaging or a labeled box, away from children. Before winter, inspect and replace worn blades so the mower is ready in spring. See robot lawn mower winter storage.

What does a dull blade cost you?

Dull blades do more harm than a ragged look. Torn grass loses more water and is more open to disease, so a lawn mowed with dull blades can look stressed in hot, dry weeks. On a battery mower, a dull blade also takes more power, so you get less area per charge and more trips to the charger. On a remote mower working tall grass, a dull blade wraps grass around the spindle and can trip the motor protection.

That makes blades one of the cheapest ways to keep both the lawn and the mower healthy.

What should you keep in your blade kit?

• A spare set of blades listed for your mower.
• Cut-resistant gloves.
• The right socket or tool for the blade bolts.
• A file or sharpening tool and a blade balancer, if you sharpen bar blades.
• A plastic scraper for the deck.
• A marker to note which way the blade faces before you remove it.

Still not sure which fits your property?

Tell us about your mower and lawn and a Yard Automation Pro will reply by email with a recommendation, or tell you honestly if none of our machines fits. Book a free consultation, or call +1 423-927-3776, 9am to 5pm EST. You can also try the Find Your Robot quiz and cost calculator.