Customers who are thinking about purchasing a flail mulcher for the first time are confronted with this question in particular. The market is full of a wide variety of devices and types ... and how can I then say which knives or mallets are suitable for my needs?
That's why I've put together some information on the most common knife shapes and written down my personal opinion.
Let's start with the Y knives:
The Y-knives are a somewhat lighter knife shape that is often installed in low-priced mulchers. Of course, there are also high-quality Y-knives with the appropriate material thickness and weight that are necessary for special areas of application ... but of that later. As a rule, these knives are made of 2 - 3 mm steel, which are ground on both sides of the legs. The advantage of these knives is that the sloping cutting edges make it possible to mulch the clippings a little smaller. The lower weight of the blades ensures that even smaller tractors with less power can cope with somewhat larger working widths. For the manufacturer, this unfortunately often means that due to the lack of impact (the more weight, the higher the impact), savings can be made on the material of the mulcher. You can see this if you look at the holders for the flails on the shaft, which on closer inspection should appear a bit “thin”. The body of the mulcher is also often formed with a smaller material thickness, because the forces that are caused by a heavy 800 gram hammer, for example, simply do not work. The cut of the Y-knife is frayed and uneasy (due to the sloping cut edges). Due to the lower weight of the knives and the resulting lack of impact, it is often not possible to smash nettles or the like.
An alternative (... or not) are the “fine-cut cup knives”.
These knives are formed from sheet metal and at first glance resemble hammer hammers. But at the latest at a second glance (or if you look at the back of the mallet) you will see that it is a sheet metal knife with low weight and little impact. One advantage is the straight cutting edge that runs horizontally to the ground and thus ensures a “lawnmower” -like cut during the first and second use. Unfortunately, due to the sheet metal material, this type of knife is very sensitive to stones and extremely "hard-wearing". The low weight of the knife results in the same disadvantages as with the Y-knife: too light, little impact force.
My personal recommendation is therefore quite clear to hammer mallet, which are available in different weight classes and in many forms on the market.
As a rule, it is a cast mallet, whereby the material composition often varies from manufacturer to manufacturer. On the one hand, the flails should be more and more resistant to stones, and on the other hand, thanks to the straight cut edge, they should of course cut a clean lawn. A material that is too hard can be sanded wonderfully, but threatens to tear if it hits an obstacle. Material that is too soft quickly loses its grind and is susceptible to more or less large indentations caused by stones etc. Each manufacturer also has a different philosophy when it comes to the weight class of the mallets used and the associated impact.
With our own brand Evotech, we are relying on 800 g hammer mallets. Just like Talex or the German manufacturer Fehrenbach, it usually succeeds in shredding not only a beautiful meadow cut (... not a perfect “lawnmower cut”, but still good to look at, straight and well-groomed), also lying around branches with a diameter of 3 - 4 cm To level molehills ... even use in the reeds is no problem, as the following photo shows.
The flails are easy to re-sharpen and have enough “material lining” for a long use. Due to the weight of the flails, the brackets on the flail shaft are almost as thick as a thumb and the body of the mulcher is also made of thick-walled sheet steel. In our Evotech models, the side panels are made from 10 mm sheet steel, for example.
The Italian manufacturer Deleks relies on a lower flail weight for its “Lince” flail mulchers, but lets the flail shaft run at a higher speed in order to come back close to the impact power of the 800 gr. Flail.
In a slope mulcher with a swiveling head or a special forestry mulcher, hammer grinders with 1200 gr. Weight are usually used, which are then able to shred wood up to 8 cm branch thickness. Of course, the mounts of the knives and the whole body are designed accordingly.
So you see, I personally would always advise you to mulcher with mallets. Pay attention to the material strength of the mulcher, look at the holders of the flail and ask for the individual prices of the flails, which can vary considerably depending on the manufacturer. Take a look, too the flail offer in our online shop
There are also many other knife variations, such as the Y-knife with a central mulching blade. I never wanted to offer this type of knife in my company, but because of this, the well-known German companies offer this particularly in their mulchers with drip tray, but now we have them in the program. Here is a picture of it.
Personally, however, I find that the distance between the knives (which is greater than, for example, a pure scarifying device) and especially the V-belt drive of the flail mower, is not a suitable knife shape for a mulching device, because the permanent scratching through the ground of the central knife, the V-belts of the drive tend to “slip through”, which is evident from the abnormal V-belt wear.
If you have any questions or suggestions about the knife types, feel free to contact my sales team of Landmaschinen Neuhaus or just send me an E-Mail email@example.com