Flail mowers explained – everything you need to know

What is a flail mower?

flail mowerFlail mowers feature metal pieces that are bent to T or Y shapes called flails. The thin end of the flails is connected to a rotating drum. The flails spin at high speed, allowing them to cut through the bush as the drum rotates. Their history dates back to the industrial revolution era. The first flail mower was made by Edwin Beard Budding & Company.

It had a large back roller that transferred the movement to a front roller equipped with blades when pushed by the gardener. In 1940, a modern petrol-powered flail mower was developed by Briggs & Stratton factory. Since then, there has been research and production of modern professional flail mowers by various companies like Peruzzo.

What do you use a flail mower for?

You can use a flail mower to give a rough cut to long grass and brambles where there may be contact with debris along the roadsides. Similarly, a flail mower is useful in mowing overgrown bushes and vines.

It is because their design minimized the risk of injury from the flying debris. Therefore, these machines are the perfect choice for mowing areas that are grassy and overgrown with other vegetation. Other uses include clearing golf courses and trimming the sides of bushes, trees, and other dense shrubberies since you can vertically position the mower.

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How do flail mowers work?

Y- or T-shaped blades or flails attached to a long spinning shaft are used for cutting in a flail mower. These blades rotate at high speed, roughly cutting any material it comes across. A PTO drive powers the spinning shaft where the flails are spaced out across and around to provide a thorough cut. They hold the cut materials under the mower for some time that allows for further shredding. It then evenly distributed the fine clippings across the mower’s full width. They rotate in the opposite direction to the wheels.

Flail mower Horsepower (HP) requirements

You require different levels of HP depending on the mowing task at hand. Flail mowers have varying horsepower between 15 -90. The higher the HP, the stronger the mower is. Therefore, a good mower should always have a high horsepower. The task to conduct may not require high HP. The Standard duty embankment flail mower has a 15- 60 HP range. They are best suited for both subcompact and compact farm tractors. The Heavy-duty embankment flail mower has a higher HP threshold that is between 50-90.

The FMHD (Heavy Duty Flail Mower) has a horsepower of between 40-90 HP. Low HP limits the performance of a flail mower. It is worth noting that the higher the HP, the higher the cost of the flail mower. Depending on the size of the mower, most tractor-mounted flail mowers require a minimum of 20-60 HP. If you are conducting simple tasks, low to moderate HP will work just fine.


Unlike rotary cutters, flail mowers contain cut debris below the cylindrical hood. Therefore, you need not worry about the flying debris. You can use flail mowers to clear vegetation and weeds in a populated area or on the roadsides.


Flail mowers can be angled to trim bushes as well as to cut banks. It makes it helpful to maintenance departments and landscapers by giving them single-unit flexibility.

Ease of repair

If a flail is damaged, you only need to replace it. It is inexpensive as you do not need to buy the entire blade.

Excellent cutting

Because it has different blades, the flail mower provides fine cutting as compared to other mowers.

Suitable for stiff materials

Flail mowers cut thicker materials like shrubs and branches with a fine finish. Therefore, they are ideal for pruning orchards or any substantial work.

Silent operation

Flail mowers do not produce unwanted noises regardless of the thickness of the material you are mowing. They are also easy to store. For easy protected and safe operation, flail mowers come with steel protection.


Due to its many moving parts, it can be time-consuming and hard to maintain flail mowers. Maintenance bills can pile up quickly unless you do the small chores by yourself.

High cost of replacement

Although flail mowers are easy to repair, replacing, the parts can be expensive. If multiple flails need some replacement, the costs significantly increase.

Expensive attachments

It is no secret that the attachments to the flail mowers are costly. For instance, besides having a tractor to pull it, you need to operate the mower.

Flail mowers versus slashers

Are you planning on buying a mower? This is a big decision, and if you make the wrong choice, it could be costly. Below we evaluate both pros and cons for both flail mowers and slashers.

The finish

Both of these mowers achieve different finishes. Therefore, considering the finish you want is crucial in deciding which one to hire or purchase. Slashers are quick when it comes to cutting the tall grass down to about two inches. They achieve a rough finish while leaving a window. A slasher should be your go-to mower over the flail mower for cutting long glasses.

On the other hand, a flail mower generally achieves an even finish. Because of the cutting and mulching the growth back, flail mowers are less likely to leave a window and give you a neater finish. Because of the above, a slasher is quicker than a flail mower.


Since they only have a gearbox and two blades, slashers are easy to maintain compared to flail mowers. Maintenance only involves checking the condition in which the blade is and the oil levels in the gearbox.

Flail mowers have many moving parts. Therefore, the level of maintenance required is high. It includes; greasing the bearings, adjusting the drive belts, checking the oil levels, and checking for wear and tear on the flails.


While budget plays a big part in decision-making, you should ensure that you buy the correct equipment for your mowing task. Lighter duty slashers are the most budget-friendly choice as they are cheaper to buy and maintain. However, there is a limit in what tasks they can perform. While most expensive to buy, heavy-duty slashers are relatively easy to maintain.

What is the extent of the area to cover, and what am I cutting?

If you’re to cut grasses, then slashers are your best option. This is because they are designed to cut grass. Flail mowers are designed in a way that they can cut the grass and mulch minor pruning. Therefore, a flail mower is more versatile as compared to a slasher. If you need not just slash but clear the land, you should consider using a flail mower because it is a general-purpose machine.

The guide below should help you decide which equipment to use, hire or buy. The other factor to consider is what size of equipment your tractor can pull.

Slashers vs Flail Mowers

What is the difference between a flail mower and a topper?

As the name suggests, topper mowers remove the tops of long grasses, scrubland, and small samplings. They feature two blades attached to a rotating carrier.


To cut back the overgrowths in your lawn to a more manageable length, a topper mower is your best option. Toppers work well with level pastures while it struggles if the pasture is uneven and rough. Compared to flail mowers, toppers are cheaper to purchase and maintain but are not as versatile as flail mowers.

The cuttings

Toppers achieve longer cuttings than flail mowers. Since the cuttings are thrown against the bottom, they are left in neat rows. It makes them easier to collect afterward.

On the other hand, flail mowers leave mulched cuttings that are short and spread. Flail mowers are more maneuverable in tight spaces. Though more expensive than a topper, a flail mower achieves more.

Also be sure to read this article for more information: https://www.blacktrac-compact-tractors.co.uk/grass-topper-vs-flail-mower/

Where to buy a flail mower, how much does it cost?

Whether you are a professional landscaper, estate owner, or farmer, a flail mower is handy equipment to add to your yard. You can purchase them from different manufacturer stores online like Iron Baltic, Land Pride, Woods equipment, and John Deere.

The prices vary depending on Horsepower, cutting width, and the model of flail mower you want. For instance, a LoncinG420F flail mower with 14HP costs $2000, while a flail mower from John Deere with the same HP costs considerably more. To purchase used flail mowers, use machinio.com, agriseek.com to mention a few.

They have a wide range of flail mowers to choose from, like frontier RC2060,2017 Braber EFGC165F, Kuhn VKD 170, John Deere 25A, among many others.

Renting a flail mower

Maybe you want to clear the yard twice a year. Or your budget may limit you. In such scenarios, you are either unable to buy one, or buying it will be a waste of money in the long run. The better option here is to rent one. It goes without saying that in some cases, renting a tool is beneficial than buying one. With renting, you need not worry about maintenance and repair costs.

Depending on the state you live in, various stores like catrentalstore.com, anoequip.com, and rentalsunlimited.com offer rental services for flail mowers. You can rent the flail mower weekly, daily or monthly. The charges are as low as $125 per day to $1250 per month. Additional charges may be included if you break the blade’s teeth or tips.

With renting, you do not incur hefty upfront costs of acquiring the tool, and you have a large pool to choose from, depending on your need.

How to sharpen flail mower hammer blades

One way of maintaining your flail mower is by sharpening its hammer blades. To do so, you can remove the blades and file them one by one and then fit them back. Alternatively, you can use a handheld grinder to sharpen the edges of your hammer blades. Handheld grinders are fast and produce a fine and sharp blade. It would be best if you sharpened both ends of the hammer blade.

While grinding, ensure that you do not weaken the blade’s temper or file to the extent of making the edges weaker. To ensure that the blades remain sharp, occasionally flip the blades to expose the unused sharp edge. Before doing this, ensure there is no oil in the gearbox.

Read more about sharpening blades here.

How to set up a Flail Mower

Set both the tractor and the flail mower on the flat and smooth ground before attaching it to the tractor. Nobody should be standing between the two. By removing the brackets, release pins, connect the lower arms first. Insert into the arms center the lift arms and fasten them using the appropriate release pin that you had removed.

Remove the pin between the plates and connect the top link of the tractor to the third upper joint. Lock it with the pin. Using the third point, adjust it such that the upper part of the frame is parallel to the ground. To reduce the stress on power take-off, always ensure that the central gearbox is parallel to the ground.

AGL off-set Flail mower Manual.pdf

Flail mower attachment for mini excavator

Attaching a flail mower on a mini excavator is excellent for mowing hard-to-reach areas like retention ponds, pond banks overhanging limbs, roadside shoulders, or even parking trails. Excavators have a high horsepower. Their long limbs make it possible to reach difficult places. Due to their high horsepower, the excavator clears the most difficult brushes in no time. Companies like Eterra are known to specialize in this area.


Flail mowers are a great addition to your farm tools. Due to their versatility and maneuverability, they can perform a wide range of tasks. Before you purchase one, consider what you intend to use it on and ask yourself, between buying and renting one, which will benefit me more?

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