4.1.5 – HOW TO – Get the longest life from your BrushDestructor Flail-Blades

This is a question that I get asked frequently from new buyers of BrushDestructor Blades and on the odd occasion potential buyers who think that such a high price blade means a longer lasting blade. This is because the new user does not get the longevity from the Flail-Blades they expected after seeing some of the photos and videos on this web site.

This BrushDestructor blade is a very expensive investment on your part, approaching a quarter to a third of the price of a brush cutter itself and reading below will help you determine if this investment is right for you.

This blade has been designed as a fire hazard reduction tool, to cut & mulch everything from standard grass, too long stringy grass, too tough vines, too all regrowth saplings up to 100mm in diameter. And to smoothy transition back and forth between all of the above materials as you clear away unwanted bush on your property.

The use of this blade comes with the responsibility to use it how it was designed to be used and to be prepared to do the regular inspections and maintenance required for the safe use and longevity of this blade.

This blade has been designed to be most effective with sharp teeth, however with blunt or not teeth, it becomes no more effective than a standard tri-blade supplied with your brush cutter. If you are not prepared to keep the teeth sharp, than it would be more cost effective for you to stay with the standard tri-blade supplied with your brush cutter.

If you own a bicycle handle brush cutter, this blade may not be suitable for you. This is because bicycle handle machines, do not give you fine and responsive control of the cutting head that you would get from a loop handle brush cutter. Meaning you are far more likely to hit rocks or other obstacles and quickly take the sharp edge off the teeth, requiring more time spent sharpening the teeth on the Flail-Blades.

This blade is not designed for close ground clearing, as the risk of hitting stones hidden in the grass and even dust sitting on these plants. Will quickly sand blast the flail-blades away, as can be seen by this photo below, where this damage was done by one customer by the end of the first tank of fuel.

To get the longest life from this blade, I recommend staying at least 300mm away from the ground, on the first pass of clearing a new area of bush. You can come back in a month or two and do a closer cut, after all the mulch has settles and started to rot away exposing any rocks and other hard objects.

If you have used a standard metal blade for some time and become use to the method of rev and bash, then this blade would not be a good investment for you. This is because brush cutters have been designed to run at high revs, so that a nylon line can smash and rip its way through soft vegetation. So if you don’t think that you can adapt your’e cutting technique of running the brush cutter at lower revs and applying gentle pressure to allow sharp teeth to do the cutting, than this is definitely not the right blade for you.

Even though this blade is used by a large number of stand alone commercial operators, one who even quickly puts a cover over the blade so that no one can see it, as it give him a considerable marketing edge over his competition.  For the large commercial operator that employ a number of brush cutter operators, who have low respect for their tools or how they use them, I do not think this blade would be financially viable choice for your business.

This blade uses pivoting Flail-Blades and a Rubber Impact Absorber, to absorb the occasional impacts with hard objects that is unavoidable with brush cutting through thick bush. That give, is to help minimise the damage to the cutting teeth of these flail-blades.

This shock absorption feature, does not mean that you can bash your way through woody material with a blunt blades as some customer do, because eventually the Rubber Impact Absorber will fail.

Below you can see how the impact absorber has failed and the flail-blade become wedged between the top and bottom hubs and I am told that it is very hard to get out.

Even though this blade is very effective at cutting all types of grasses, even in a blunt stage. There seems to be a trend, where it is increasingly being used in residential properties and even being used as an edger. This is not what this blade was designed for, the edging of pavement and hitting concrete or stone walls will cause excessive wear of these flail-blades and the early failure of the rubber impact stop.

This blade, cuts better at lower revs, however if you have become accustomed to using full revs and don’t think adapt to using lower revs. Then this is not the blade for you.

If you have developed the bad habit of cutting on the backward stroke, which is when you swing the brush cutter from your left to your right, or when you are using the 12 to 4 o’clock area of the cutting head. Hitting an object with the 12 to 4 o’clock area of a blade, causes the flail-blade to dig in and then are flung backwards and forwards with greater velocity than the blade is traveling, Resulting in massive kickback that can also destroy the rubber impact stop.


You should only ever cut on the forward stroke, (right to left), which allows you to cut cleanly through the job.


This blade has been designed and tested over the last twelve years using a 22cc & 35cc Honda brush cutters and so I cannot guarantee the longevity and integrity of this blade when used on higher powered brush cutters. So if you own a very powerful brush cutter and don’t think you can adapt you’re cutting technique to use sharp teeth, not rev and bash. Then this is not the blade for you.

However, used correctly, you will be amazed at the ability of this blade to clear all manner of overgrown vegetation and at its longevity. See Customer REVIEWS.

Speaking of Longevity, I have had two customers come back to me complaining that the steel is not hard enough and this blade does not last as long as implied on this web site. Probably because I have mentioned that I have had to lower the hardness of the steel to reduce its brittleness for liability reasons.

At the original hardness of HRC 48, a hard impact would likely chip a large chunk of the blade off. Going down to HRC 47, a hard impact could chip the whole tooth off. With the current hardness of HRC 46,  the cutting edge of the tooth with deform without chipping. So with the high speed impacts that a flail blade has to deal with, there is only three levels between being too hard and brittle and being too soft where the tooth looses its edge too quickly. However, the difference between these hardnesses makes very little difference, as to how quickly the metal can be sand blasted away.

The photo below sent in by customer, shows the wear of the flail-blade after only a few tanks of fuel, compared to a new blade. I asked him return the blade for inspection and testing.

I resharpened these flail-blades using the new M-22 sharpening jig to mark the new tooth line, and then tested these blades myself for a couple of tanks of fuel.

Below is the same flail-blade after a couple of tanks of fuel, where you can see that the edge of the tooth is polished off, after clearing everything from grass to 100mm saplings.

When you look closely, you can see that most of the sand blasting of the flail-blade is on the underside, which suggest to me that this blade was used for close ground clearing. If the sand blasting was even on top and bottom surface with a nice round edge, this would suggest that it was used in a very dusty environment where there was a lot of dust sitting on leave and the bark of trees being cut.

If you live in a very dusty environment, or must cut close to the ground, do us both a favour and use the blade supplied with your brush cutter. If you are not happy with its performance and you obviously wont be if you are looking for something better. Grind some shredding teeth on the front edge, this will improve the performance of that blade.