2.4 – Safety Warning For Flail Type Brush Cutter Blades

This page is about Flail Type Blades for brush cutters, how there have been injuries and a death caused by them and how they have now been band from being fitted to brush cutters in the EU member states. And unfortunately both the Australian made BrushDestructor and Weedwakka flail blades falls into this category as well.

Safety Warning - Unsafe Flail Type Brush Cutter Blades (600x248)

One thing I really hate and I am sure you do as well is finding out after you have brought something, that it does not meet the expectation you were sold on; It does not work as well as implied; it does not comply with your local regulation or in fact could be illegal to use in your country.

This page has been created to give you all the information you need, to make an informed buying decision and I urge you to read this before going ahead and purchasing one of my BrushDestructor Flail Type Brush Cutter Blades.

On the 19th January 2012, the European Commission set a directive requiring Member States to prohibit the placing flail type blades to portable hand held brush cutters. You can read the complete directive at the very bottom of this page.

In the UK in 2010 a fatal incident occurred, involving the use of a twin chain flail type after market brush cutter blade as shown below.

Chain Flail Type Brush Cutter Blade (600x298)

Now I do not believe in marketing my product by running down another companies product, but in this case I have to make an exception. A Chinese copy of this Brogio chain flail blade, is still on sale  to this day and can be found for sale on eBay in Australia and probably the US as well in 2017. The real concern to me as these two countries are my main markets.

Chain Flail Blades (600x498)

If a fatality should occur from the use of one of these blades, than the Safety Standards Authorities in these countries could, (in the same nee jerk reaction as the EU), just simply claim all flail type brush cutter blades are dangerous and ban then all. So I decided that I would do some searching to see if there were other types of flail blades that were potentially unsafe and as you can see by the photo below there are a lot of all sorts of different types on the market around the world. With many of them in my opinion, based on the knowledge I attained with all the testing I have done, range from possibly safe to extremely unsafe.

Types Of Brush Cutter Flail Blades Sold Around The World (602x848)

You do have to wonder why there are so many different types of brush cutter blades on the market, well its because the ones supplied and recommended by the brush cutter manufacturer are all absolutely useless (the back of my shed is full of these blades rusting away never to be used again). If they did a decent job, you would not find such a range of after market blades and those shown in the picture above are only the flail blade types. There is probably three times as many, other types of brush cutter blades to be found on line.

One thing the EU Directive states (They are also liable to eject stones with higher energy than single part metal blades), this is again another nee jerk reaction based on the fault of one type of flail blade being assigned to all flail type blades.

I have personally not used a chain type flail blade, but I can see how the very shape of the chain could hook and fling stones with considerable force just like the old style catapults. A thin flail blade, on the other hand will eject stones at a slower velocity than a fixed metal blade, because part of the energy of the impact will be spent flicking the flail blade back. With a fixed metal blade, there is no give and all the energy of the impact will go into ejecting the stone or any other objects out of its way at a higher velocity.

I have been using various versions of my flail blade in all sorts of extreme conditions for about six years now and I am ashamed to admit that due to the very hot Australian summers, I have not always worn the safety clothing that I should. In this time, I have been hit by stones and bits of wood in the legs, arms and stomach, but what hurt the most was being hit in the throat and the nuts. However, never in this time has any of these hits left a bruise, or cut my skin or ever drawn blood. I would like to point out, that I always wear a full face screen and protective glasses, ALWAYS.

Of all the blades shown above, the most dangerous are the chain flails with a chunk of metal at the end.

There are a number of reasons for this;

(1) The steel used in chains are made to be very strong in tensile strength to withstand high tension loads. They are not made really hard and yet it is hard steel that is required to withstand the high abrasion wear between the links of chain.

(2)  The high wear between the links of chain, is because the steels of each link are made of the same metal and no lubrication will stay in place under the high centrifugal loads. The only way to get reasonable wear between a steel to steel sliding joint without any lubrication, is to use different types of steel and hardnesses.

(3)  The largest problem is the heavy chunk of metal at the end of the chain. What this does is place the centre of gravity of the combine flail blade further out from the centre of rotation. What this means is, there is a vary high centrifugal load placed on the chain links, which again increases the wear between the chain links.

Problem with weighted chain flail blade for brush cutters

(4)  The straight flat flail blade will flap up and down as it spins around. This happened with one of my early prototypes, but I suspect that this will be even worse because there is not top and bottom plate to prevent this flapping. This rotation of the flat bar blade, under very high loads will accelerate the wear of the chain links leading to premature failure.

(5)  And finally, because this type of blade is not a cutting blade, it relies on high velocity to smash its way through grass. This means running the brush cutter flat out all the time just to cut grass and watery weeds. It is this high speed that leads to excessive wear on the chain links and a high velocity metal projectile when the chain fails. The Chain itself would also produce a lot of drag, but when it gets clogged up with grass it would drain a lot of power just to turn it round. So you would have to put up with the noise of the brush cutter screaming at full revs all the time.

Brogio - Dangerous brush cutter blades

It is lucky the auto and aviation industry safety authorities are much more thorough in there investigation of a safety issue and make recommendations to solve the problem so it does not happen again, not ban it outright. Heaven forbid, if there should just happen to be one death from a car or plane accident in one model of car or plane, they would ban all cars and planes. We would all now be walking and debating the problem of bans on shoe laces, because if they came loose you could trip, hit your head and kill yourself.

Of cause Stihl has jumped on the bandwagon and banded the use of flail blades on their brush cutters. Actually they have banned all blades not approved by them, which in English, means you can only fit a blade sold by one of their shops. Since Stihl is the main manufacturer that uses a 20mm diameter arbor, probably to ensure users of their brush cutters fit only their blades, so when my stocks of 20mm arbor blades run out I will not be ordering any more as they now account for only about 1% of sales.

The Directive also states (The metal parts of flail-type cutting attachments and their linkages are subject to repeated high mechanical stresses when they come into contact with stones, rocks and other obstacles and are liable to break-up and be ejected at high speed). Obviously in their misguided opinion, a one piece metal blade is not subjected to these mechanical stress and never fails or breaks up.

Why then would every single manufacturer of brush cutters, state in their manuals, to always inspect blades before each use to check for any signs of cracking. I remember in one manual, saying the best way to check your blade for cracks, because cracks are hard to see on a dirty blade. Is to take it off and tap it with a metal object, if it now has a dull ring to it where it had a bright ring before, than it has a crack in it and it should no longer be used.

Yes it is true that linkages and pivot points are subject to not only high stresses, but extreme mechanical stresses. You can read about the problems I have faced and overcome here; Problems, Causes, Solutions. It is the solving these problems, that has allowed me to produce a blade that is way superior to any one piece metal blade that is currently on the market todate.

I have decided, because of this statement written in a HSE Directive, (The Health and Safety Executive (HSE) has become aware of a dangerous practice involving the fitting of non-standard accessories, not approved by the manufacturers, to brush cutting machines) and the fact that Stihl & Husqvarna, have and will distance themselves, by not allowing the fitting of non standard blades to their brush cutters.

Stihl must have sent out a notice to all their distributors, because I had one customer in New Zealand that purchased one of my blades and wanted to buy a new heavier brush cutter to go with the new blade. He went to a Stihl outlet in his town and asked them what bush cutter would best suit his body size and this blade. They told him that if he was going to fit a BrushDestructor blade to a Stihl brush cutter, than they would not sell him a brush cutter and they didn’t. He tried to get them to at least look at this web site, before making such a closed minded decision, but they would not. I guess the German arrogance, has been indoctrinated into their distributors as well. It is just like there web site that gives absolutely no information about their brush cutters at all. After all, it is German, what more do you need to know.

I have over the last couple of years, offered my end user knowledge and design skills to a number of brush cutter manufacturers since there has been very little improvement in design to brush cutters for at least 15 years. However, not one of these companies has ever had the professional courtesy to reply to any of my emails. After all, what would a hillbilly from the mountains in Australia of all places, know about brush cutters.

So I guess there is only one answer to this, now that my flail blade has pretty much reached the pinnacle of its design, I will now design, build & sell my own machine. Designed specifically to work with and get the best of the BrushDestructor Blade. The BrushDestructor Blade, will be the specified Standard Accessory on the new BrushDestructor Machine.

If you have suffered an injury while using a metal brush cutter blade and would like to share this with me, I would appreciate hearing from you. The more useful information I can add to this page, the more it will give future buyers of flail type brush cutter blades the right information to make an informed purchasing decisions.

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of 19 January 2012
requiring Member States to prohibit the placing on the market of flail-type cutting attachments for portable hand-held brush cutters
(notified under document C(2011) 9772)
(Text with EEA relevance)

Having regard to the Treaty on the Functioning of the European Union,
Having regard to Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC ( 1 ), and in particular Article 9 thereof,
(1) Grass trimmers and brush cutters are portable hand-held gardening and forestry machines used for cutting grass, weeds, brush, small trees and similar vegetation. A complete grass trimmer or brush cutter unit includes a power head, a power transmission shaft, a cutting attachment and a guard. Many combustion engine driven machines are dual purpose machines that can be used for cutting grass and weeds or for cutting brush and small trees, depending on the cutting attachment fitted.

(2) In September 2008, the Swedish authorities informed the other authorities of Member States and the Commission that several flail-type cutting attachments for brush cutters, consisting of two or more metal parts such as chains, knives or brushes linked to a rotating head, were being placed on the market by manufacturers other than the original brush cutter manufacturers. The Swedish authorities considered that such flail-type cutting attachments were dangerous.

(3) In May 2010, the authorities of the United Kingdom informed the other authorities of Member States and the Commission of a fatal accident involving a flail- type cutting attachment for a brush cutter consisting of two chains linked to a metal disc. During use of a brush cutter fitted with such a cutting attachment, a link of the chain had been ejected and had fatally injured a bystander. The United Kingdom had taken measures to ensure the withdrawal from the market and from service of the cutting attachments concerned. At the meeting of the Machinery Committee held on 2 June 2010, the United Kingdom requested the Commission to examine the need for the adoption of a measure requiring Member States to prohibit the placing on the market of cutting attachments having similar technical characteristics.

(4) Flail-type cutting attachments for brush cutters placed on the market separately in order to be assembled with a brush cutter by the operator, not covered by the risk assessment, the EC declaration of conformity and the instructions of a brush cutter manufacturer, are interchangeable equipment according to the definition set out in point (b) of Article 2 of Directive 2006/42/EC.


(5) Section 1.3.2 of Annex I to Directive 2006/42/EC on the risk of break-up during operation requires the various parts of machinery and their linkages to be able to withstand the stresses to which they are subject when used. Where a risk of rupture or disintegration remains despite the measures taken, the parts concerned must be mounted, positioned and/or guarded in such a way that any fragments will be contained, preventing hazardous situations. Section 1.3.3 of Annex I to that Directive on risks due to falling or ejected objects requires precautions to be taken to prevent risks from falling or ejected objects.


(6) The harmonised standard for portable hand-held combustion engine driven brush cutters, EN ISO 11806:2008, includes technical specifications and tests to ensure the adequate strength of cutting attachments and to reduce risks due to thrown objects. The standard does not foresee cutting attachments consisting of more than one metal part. While application of the harmonised standard is voluntary, the standard indicates the state ofEN 21.1.2012 Official Journal of the European Union L 18/5 ( 1 ) OJ L 157, 9.6.2006, p. 24. the art to be taken into account when applying the essential health and safety requirements of Directive 2006/42/EC, according to the general principles set out in the introduction to Annex I to Directive 2006/42/EC.


(7) The use of flail-type cutting attachments with linked metal parts gives rise to significantly higher residual risks of break-up during operation and of ejection of objects than single part metal blades. The metal parts of flail-type cutting attachments and their linkages are subject to repeated high mechanical stresses when they come into contact with stones, rocks and other obstacles and are liable to break-up and be ejected at high speed. They are also liable to eject stones with higher energy than single part metal blades. The guards fitted to portable hand-held brush cutters cannot provide adequate protection against the higher risks created by flail-type cutting attachments with linked metal parts. Consequently, taking account of the state of the art, flail-type cutting attachments for portable hand-held brush cutters cannot be considered to comply with the requirements set out in sections 1.3.2 and 1.3.3 of Annex I to Directive 2006/42/EC. That non-conformity gives rise to a significant risk of serious or fatal injury to users and other exposed persons..


(8) On 22 October 2010, the Commission consulted the European Garden Machinery Federation on a draft measure to deal with dangerous cutting attachments for brush cutters. In its reply dated 4 November 2010, the Federation expressed support for the draft measure.


(9) The shortest possible period should be allowed for the application of the measures required by this Decision in order to prevent further accidents.


(10) The measures provided for in this Decision are in accordance with the opinion of the Committee established by Article 22 of Directive 2006/42/EC,
Article 1
Member States shall prohibit the placing on the market of flail-type cutting attachments consisting of several linked metal parts for portable hand-held brush cutters.
Article 2
Member States shall take the necessary measures to comply with this Decision by 30 April 2012 at the latest. They shall publish those measures and forthwith inform the Commission thereof.
Article 3
This Decision is addressed to the Member States.
Done at Brussels, 19 January 2012.
For the Commission
Antonio TAJANI
Vice-PresidentEN L 18/6 Official Journal of the European Union 21.1.2012

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