How do Lawn Mower Blades Cut Grass: The Science Demystified

Lawn mowers have gone through a revolution.

Decades ago, animals roamed farms, feeding on grass and effectively trimming it.

Naturally, that won’t cut it in modern times, and so modern lawn mowers are now available, complete with comfortable seats and cup holders to make the experience much more fun.

A lawnmower has a deck, mostly made of steel for longevity, and inside is sits blades that will cut grass. The deck, which is supported by four wheels has a bag attached to it for collecting the cut grass, and also the motor sits right on top of it.

When the blades cut grass, this very deck prevents it from flying all over the place. The motor of a mower determines the pace at which it cuts grass.

An internal combustion engine powers this whole process, and it could either be two-stroke – using oil and gasoline to move internal parts – or four-stroke with a completely different lubrication system. How do mower blades cut grass?

They are totally different from other cutting tools such as scissors.

Because blades of varying lengths are attached to spindles at different lengths, they work by creating a suction-and-tearing movement. A blade will rotate on a horizontal plane, create continuous airflow, and then the blades that will now be rotating with tear the grass underneath.

This creates an upward movement of grass right before it is chopped down by the rotating blades. The blades rotate quite fast – at about 3,000 revolutions per minute, and they can be curved depending on the type.

It is the tip of the blade that does all the work.

Here are some of our favorite Environmental Friendly lawnmowers

Cut and Mulch

Some blades cut the grass as it fells on the side of the deck, while others are designed to chop it into tiny pieces for mulching. In this case, the deck will contain the grass until they are cut into these tiny pieces by the mulching tool, and then releases them to the side of the deck.

If you have an attached mulching bag, then you make it much easier to clean up after the exercise. Most rotary push mowers run on gasoline and other liquid fuels because they are powered by internal combustion engines.

Lately, a notable number of mower manufacturers are making cordless electric mowers that are rechargeable after the specified duration in a bid to reduce emissions.

Types of Lawn Mowers

There are five main types of lawnmowers.

1. The Push Reel Mower

picture of a push reel mower

Before any other fancy grass-cutting machine was made, there was this simple yet effective push reel mower.

They feature 5-8 small blades that rotate regularly by a stationery larger blade mounted at the rear of the mower.

As they all move past the lone blade, they cut grass into tiny pieces and deposit them on the side.

They are not engine-operated, and so they are only ideal for small lawns.

2. Walk-behind Power Lawn Mower

picture of a walk-behind power mower

They can either be rotary or reel, gas-powered or electric.

They are still some of the most popular in the world currently for their price and ability to do a neat job.

They are easy to maintain, can cut grass of varying lengths, and the electric kind is now available in cordless variations.

These mowers can be used both commercially and residentially.

3. Ride-on Lawn Mowers

picture of ride on mower

They are made for larger lawns, and so they have comfortable seats and handy controls.

They could be fitted with a regular wheel or steers for control. They can also be regular tractor mowers or zero-radius that turn at 180 degrees, leaving no patches of uncut grass.

They are quite expensive and ideal for both residential and commercial use.

We pinned CubCadet’s Tractor Mowers against John Deere’s Tractor Mowers.

4. Hover Mowerspicture of a hover mower

They work by pushing air down, effectively creating a cushion that lifts the mower up. The mower then floats on top of the grass, cutting it and leaving the shredded pieces on the ground.

Their bodies have to stay light, and so they are made of plastic. They are usually ideal for small lawns.

5. Robotic Mower

picture of a robot mower

This mower works unsupervised. You only have to place wires on boundaries that you don’t want it to cross, and then leave it to do its job.

Some robotic mower is even able to go back to their recharging docks to power up when they are running on empty

They are becoming popular for busy folks in residential areas.

Final Word

Riding mowers have become even more popular, and especially the z-turn for its smooth delivery.  New innovations keep making mowers even more comfortable and effective.

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