Identify the cutting system before ordering robot mower blades. On a mower with pivoting blades, the replacement must leave each blade free to pivot using the specified hardware. A rigid cutter or a second edge-cutting disc can require a different parts list. The safe endpoint is a complete, correctly fitted cutting system—not merely a mower that starts after the change.
This guide is based on manufacturer documents, checked September 28, 2026. We have not performed a hands-on blade comparison. The procedure below is specifically an Automower pivoting-blade example; use your exact mower’s manual for service access, parts and shutdown.
Make a parts list before opening the underside
| Record | Where to confirm it | Why it matters |
|---|---|---|
| Model and product number | Mower label and matching manual | A brand name alone does not identify the correct blade kit. |
| Number of cutting discs | Parts diagram | Some models have a separate edge-cutting disc. |
| Blade and screw part numbers | Manufacturer’s parts list | Hole shape, thickness and screw design must match the cutting system. |
| Quantity per complete change | Maintenance section | A pack’s blade count may cover several changes—or less than one complete mower. |
| Required shutdown and tools | Model-specific maintenance instructions | STOP, parking and fully powered OFF are not interchangeable instructions. |
For example, the 305E/310E NERA operator manual requires the three blades and screws on the cutting disc to be replaced together. Do not turn that count into a rule for every mower or every additional disc.
Decide whether this is routine replacement or a repair
- Worn blades with an intact mounting system: follow the maintenance procedure and use the correct complete kit.
- A missing blade or screw: stop operating, account for the missing parts and inspect the attachment point before fitting replacements. Keep people and pets away from the affected area until it is checked.
- A cracked disc, damaged thread or loose mounting point: a new blade does not repair the mounting system. Have it assessed.
- New vibration after replacement: stop and inspect the installation. Do not keep mowing to see whether it settles.
Poor cut quality can also involve grass height and mowing conditions. Inspect the blades safely; do not diagnose wear from the lawn appearance alone. Our cutting-height guide covers the setting separately.
Documented example: Automower pivoting blades
Husqvarna’s blade-change instructions specify original blades and fresh screws at each change, protective gloves and a fully powered-off mower. Follow the shutdown method for your control panel. Place the mower on the specified soft surface, access the screws as the manual shows, remove the old parts and clean the accessible mounting area. Install one new blade per new screw and repeat for the complete set.
In that design, the installed blade should pivot freely. Do not clamp it rigid to “make it safer,” stack blades or mix worn and new blades. For a different brand or cutter design, use its documented fastening procedure instead. If the correct screw cannot seat properly, stop; do not improvise a longer screw or repair a damaged thread by force.
Check the work before returning to service
- Account for old parts. Compare the removed parts with the diagram and inspect the work area for anything left loose.
- Check each attachment while powered off. Confirm the specified hardware, blade orientation, complete set and required movement.
- Restore covers and the normal operating position. Follow the manual’s restart procedure in a clear work area, keeping people and pets away.
- Observe from a safe distance. Stop for an abnormal sound, vibration or error. Never inspect or touch the cutting system while it is operating.
Build a maintenance record instead of guessing an interval
Keep the replacement date, operating hours if available, blade-kit part number and why you changed it. On supported Automower models, Husqvarna documents a blade-usage timer in the app; resetting it after a real change makes the next record more useful. It does not inspect blade condition for you.
| Date / hours | Observation | Action and outcome |
|---|---|---|
| ________ | Worn edge, damaged blade, impact or routine inspection | Part number, complete set changed, check completed |
| ________ | Condition at next safe inspection | Keep in service, replace or refer for repair |
There is no verified universal number of weeks for all lawns and blade types. Use the manufacturer’s inspection guidance and your recorded condition. For budgeting, divide a compatible kit’s price by the number of complete changes it provides, then use your actual replacement history in the running-cost worksheet.
Update — September 28, 2026: Replaced general fault advice with model-specific blade and screw checks and a maintenance record.