How to choose a lawn mower blade

A lawn mower blade is chosen first by compatibility, not by appearance: two blades that look alike may have a different centre hole or bolt spacing. This guide helps you identify the right part in a few minutes.

1. The easiest way: the original part number (OEM)

Most blades carry a number engraved or stamped near the centre hole. You can also find it in the mower manual or in the manufacturer's exploded parts diagram. Type this number into the search bar: our product pages list the compatible original part numbers.

Do you know the brand and model of your machine? Use the search by brand and model, or the "Check my model" button on the product page.

2. No part number? Measure your blade

Remove the blade (see the safety instructions below), lay it flat and take the following measurements in millimetres:

Length — from one end to the other, in a straight line. This is often the cutting width stated on the mower (for example 46 cm or 53 cm).
Centre hole diameter — the diameter of the centre hole, and its shape: round, star, hexagonal, bow-tie…
Mounting holes and spacing — the number of holes around the centre hole, their diameter and the distance between their centres.
Width — measured in the middle of the blade.
Thickness — with a vernier calliper if possible; a blade thinner than the original wears out faster.

Compare your measurements with the "Specifications" table on the product page: the length, centre hole and bolt spacing must match exactly.

3. The right type of blade

Standard blade (with wings) — the raised wings create the airflow that sends the grass into the collector.
Mulching blade — a shaped profile that chops the grass finely and leaves it on the lawn as a natural fertiliser. Use it if your mower is set up for mulching.
Tractors and ride-on mowers — the cutting deck often has two or three blades, sometimes turning in opposite directions (left-hand and right-hand blades). Always replace them as a complete set to keep an even cut.

4. When to replace the blade

the blade is cracked, bent or has hit a stone or a stump;
the wings are worn or thinned;
the grass is torn rather than cut (yellowed tips after mowing);
the mower vibrates more than before (unbalanced blade).

A slightly blunt blade can be sharpened, provided it is rebalanced afterwards. Never straighten or weld a bent or cracked blade: replace it.

5. Safety when fitting

Petrol engine: disconnect the spark plug lead. Electric or robotic mower: remove the battery or unplug the mains lead.
Wear thick gloves and block the blade (wooden wedge) before loosening the bolt.
Tip a petrol mower with the air filter side up to avoid oil and fuel leaks.
Refit the blade the right way round (wings towards the deck) and tighten the bolt to the torque specified by the manufacturer; replace the bolt and washer if they are worn.

Need advice?

Send us the brand, the model and, if possible, a photo of your old blade with its measurements: we will tell you which part fits. Contact us.