Disks For Gas Cutters: What Are, How To Pick And Install?

Knives for Lawn Mower. an irreplaceable thing. It is enough to choose the right one, and you can mow huge areas of grass with their help. Of course, the variety of knives somewhat complicates the task of selecting them. To understand which cutting element is needed, you need to familiarize yourself with the main ones. You should also find out in advance about the correct sharpening and operation of knives.

Species overview

For Lawn Mower preference should be given to special knives. They allow you to mow higher and tougher grass than fishing line. In addition, the knife is suitable even for trimming young bushes.

There are many types of discs that differ in cutting edge, shape and material of which they are made.

Each species has its own characteristics.

For cutting edges

  • with two teeth. for young soft grass, lawns;
  • with three teeth. for young grass, dead wood, weeds;
  • with four teeth. for hard grass and young shoots of trees;
  • with eight teeth mowing grass without strong chopping;
  • with 24 teeth. for hard and dry grass, shrubs, thin trees;
  • with 40 or more teeth. for mowing any grass, bushes, trees;
  • from the 80th and more. for professional motokos.


  • with two. for soft and low braids;
  • with three. for mowing weeds;
  • with four or more. for mowing grass on hay.

In shape

The shape distinguishes knives with disk blades and several blades that are at a certain distance from each other. The shape of the blades may also vary. It is worth noting that this does not affect either the speed or the quality of work of the motocosa.

Currently, manufacturers have begun to offer, in addition to traditional shapes, more triangular, rectangular and trapezoidal.

By material

The disc for the brushcutter can be made of metal or plastic. It should be clarified that for electric scythes, plastic blades should be preferred. They are great for the curved bar of this tool, which does not too separate the working area and the legs of the mowing. Plastic knives are able to mow well overgrown dry grass, for example, nettles or burdock trunks.

Metal knives are only suitable for gas trimmers. This is due to the even bar, which removes the disc from the legs to a safe distance. Handles of a special shape also contribute to safety. When hitting a solid object, part of the shock is extinguished by the engine clutch. Knives made of iron are suitable for mowing grass from large areas, weeds, shrubs, young trees.

Manufacturers Overview

There are a lot of manufacturers of disks for motokos. It is worth getting acquainted with the most popular among them. For instance, Bosch brand is known for its two and three-blade knives. A feature of knives of this company is that each of the blades can be replaced separately from the others.

Another company known for its blade knives is Shark. The advantage of the design is that the blades are fixed relative to each other at an angle of 120 degrees. As a result, it is easy to adjust each of the blades, which is convenient for different vegetation. Another feature of knives from this manufacturer is low weight.

Husqvarna is also known for its multi-tooth knives., especially with hay knives. Ideal for thick and dense grass. Of the minuses, it is worth noting the large weight of the disks and the fact that you can’t turn the knife over if one of its sides is sharpened.

Inforce knives do a good job with undergrowth and branches. In practice, the metal from which the cutting elements are made shows itself to be very durable. The only thing is that in some models the victory taps erase very quickly.

Video: Disks For Gas Cutters: What Are, How To Pick And Install?

Disks cope equally well with different types of grass, as well as shrubs and trees.

Rezer wheels perfectly mow grass, weeds, branches. The teeth withstand even cutting down trees 6 and more centimeters thick. However, they have a drawback in the form of winding grass on the shaft.

Patriot produces quality knives. Users note that if you select the right drive for a particular job, it will last a long time and amaze you with its performance. Knives from this manufacturer are very easy to grind on their own.

How to choose?

When choosing a knife for a mower, you should pay attention to many points. For example, discs with metal teeth are most often made in the shape of a circle. The teeth may vary in shape, appearance, size. For small trees, as well as thick grass, it is better to give preference to discs with a large number of teeth.

It is worth noting such an advantage of milling circles for motokos as a quick set of revolutions. However, a high moment of inertia does not affect the drive unit of the unit in the best way. For thick mowing, for tall, as well as for small rough grass and shrubs, it is better to choose circles with 40 or more teeth and perforation. They are able not to grind vegetation, and at the same time it will practically not be wound around a circle. If the number of teeth is more than 60, then you can safely mow grass and trees with a trunk thickness of up to 7 cm.

Disks with a solid blade and without holes have a large mass, so they should be selected for powerful trimmers (more than 40 cm3). At the same time, it is convenient to mow rare grass and dead wood, they are also suitable for mowing with different densities.

Discs with victorious soldering should be selected for mowing plants near obstacles. If you need to mow grass on hay, you should give preference to steel knives with a large number of teeth with smooth sharpening. Solid discs with a number of teeth from 16 to 32 cut plants with thick stems well.

For low-power trimmers, blade discs with a minimum moment of inertia are best suited. The smaller the blades, the stronger the tool will grind the grass. So, disks with two blades are most often used for mowing homogeneous grass. The main advantage of this species is that it throws the cut plants to the side.

When harvesting hay, it is recommended to choose knives with four blades so that the grass is not chopped.

The thickness of the blades is also important when choosing. Discs can be stamped or forged. The former are notable for their low price, but at the same time they can be severely damaged when faced with an obstacle. As for the forged discs, then they do not form chips and cuts in a collision with solid objects.

For electric trimmers, only plastic knives should be selected. Their low weight will not create an extra load on the engine. Soft plastic allows the knives not to break while being on an obstacle, but simply to bend or deform slightly. Use of such cutting elements is recommended for mowing thick soft grass.

How to sharpen and deliver?

With constant use, benzokosa will sooner or later begin to need regular maintenance. One of the important points is the timely sharpening of knives. A metal disk, of course, can work in a dull state, but you can not use it. This leads to reduced performance, overheating of the engine, wear of the gearbox. Sharpening teeth or blades is not difficult at all, but if you wish, you can simply install new knives.

  • First of all, the knife is removed from the device. Sharpening directly on the scythe is not recommended, as it is unsafe.
  • Next, you need to inspect the cutting element for chips, cracks, damage. If they are, then you will need to install a new disk.
  • For sharpening knives, you can use a file, sharpener or grinder. The safest tool is a file that even a beginner can handle. For sharpening, the knife is placed in a vice, and then manually processed at an angle of 30 degrees. This method is considered the highest quality.

When using a grinder, it is important not to overheat the metal, otherwise the disk will quickly become unusable. A grinder with a thin abrasive wheel is suitable for sharpening discs with many teeth.

  • At the end of sharpening, the disk can again be installed on the trimmer and check how effectively the tool works. The sharp parts of the knife cannot be taken to avoid injury.

Over time, the knife wears out and should be changed. Installing a new disc on a trimmer is a snap. This procedure takes no more than 5 minutes if you follow a simple instruction.

  • First you need to remove the protective cover, but on some models it may remain. For example, metal casings cannot be removed from the brushcutter.
  • Next, take the key with six faces (hexagon) and use it to lock the gearbox. The hole for blocking must be sought from the side or from the end.
  • After that, the mowing head must be twisted from the brushcutter.
  • Then a disk will be installed in its place. It is worth paying attention that the inner diameter of the knife should be completely located in the groove reserved for this. The front side of the nozzle should be placed upside down.
  • Now you need to fix the disk with a special washer and screw the fixing nut counterclockwise. Before doing this, it is necessary to lock the gearbox shaft.
  • The last stage is the installation of a protective casing made of plastic.