Criteria for selecting discs on grass trimmers and instructions for replacing them
Grass trimmers mow through the use of mowing head with a line and metal discs. Each type of cutting device has its own fundamental features. The use of fishing line is limited by the type of vegetation, so where the head with cord can not cope with the task, a metal disc is used. How to choose a cutting blade for a grass trimmer, what they are, and how they are sharpened, we clarify the details before buying the appropriate equipment.
Initially, we note that metal discs can be used not only on petrol, but also on electric trimmers. The main condition for using metal cutting blades on the equipment is that the transmission mechanism (shaft or reducer) must be of the rigid type in the tool design. A rigid type reducer is a metal shaft that transmits torque from an electric or gasoline engine to the tool.
There are models of trimmers with flexible shafts, in which the reducer design is represented by a steel cable. As a rule, these are low-powered electric lawnmowers that are not designed for high loads, as well as home lawnmowers. It is impossible to use metal disks on trimmers with flexible shafts (only plastic disks can be used), because this will lead to a rapid failure of the gearbox. Before you buy metal cutters, you will need to find out the type of transmission mechanism of your tool. Rigid or flexible.
What type of transmission mechanism is used on the trimmer is specified in the technical description to the tool. If the grass trimmer has a curved boom, its design uses a flexible shaft. Tools with a straight boom can be equipped with rigid and flexible gearboxes, which depends on the power of the grass trimmer.
Trimmer blades are classified according to such characteristics:
- Material of manufacture. They come in plastic and metal. Plastic knives are less efficient than metal knives, but they do not put more strain on the tool’s shaft and drive mechanism. Plastic discs are used on electric trimmers and petrol trimmers for domestic use
- Design of the cutting units. Steel discs come in two types. Bladed and toothed (milled). Plastic blades are available in the form of blades. Toothed devices have a similar design to circular discs, while paddle discs have large, flat blades
- Number of cutting edges. Number of teeth and blades on the discs are different, which affects cutting performance. Toothed discs have up to 80 links, while paddle discs have one to four links
- Additional coating. Steel toothed discs are additionally equipped with pobedite tips for use in hilly terrain. When in contact with obstacles like stones and earth, teeth are not deformed and do not blunt, which is achieved by tipped teeth. Specialists claim that carbide-tipped blades do not last very long. Brazed edges wear out quickly and the cutter is then used without the winner
Plastic blades for trimmers are not only less expensive than metal blades, they are also less stressful on the motor and transmission system. This is especially true when the blade bumps into obstacles. The more elastic the cutting blade, the less likely the plastic discs will buckle.
This is interesting! Toothed discs with a large number of links are used for mowing different types of grass. Dry grass, green lawn grass and thick-stemmed grass. The cut with such a disc is straight, clean and even. In addition, the large number of teeth eliminates their rapid blunting, and the presence of additional holes on the surface of the wheel (peoria) is designed not only to cool, but also to reduce weight and increase inertia.
An overview of manufacturers
The number of manufacturers of discs for brushcutters is enormous. Read about the most popular ones. For example, the Bosch brand is known for its blades with two and three blades. The peculiarity of the knives of this firm is that each of the blades can be replaced separately from the others.
How to Assemble Trimmer Head Brush Cutter #7389079481 #7389588101
Another company known for its paddle 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 the low weight.
Husqvarna is also known for its knives with multiple teeth, especially the hay knives. Ideal for dense and thick grass. The disadvantages are the great weight of the blades and the fact that it is not possible to turn the blade if one side has been sharpened.
Inforce knives are good for cutting undergrowth and branches. In practice, metal of which cutting elements are made is very durable. The only thing is that in some models victory tips wear out very quickly.
Positive feedback is often received on knives from Maruyama. They are characterized as very strong and durable.
The discs are equally good for different kinds of grass and for shrubs and trees.
Rezer discs are good for grass, weeds, twigs. The tines even hold up well to cutting down trees 6 cm thick or more. But they have a disadvantage in that they can wind grass around the shaft.
The Patriot company makes quality knives. Users note that if a disc is well matched to the job, it will serve for a long time and surprise with its productivity. Blades from this manufacturer are very easy to sharpen on their own.
Steel blades are made of carbon steel or alloyed tool steel, with Pobedite tips on the teeth and blades. Steel discs are mounted on heavy-duty professional machines. They can mow any grass, shrubs, trees up to 70 mm in diameter.
Plastic blades are used only for low-power models. Mow low weeds or mow lawns. Plastic is not good for brushwood.
Which manufacturers are trustworthy??
In our opinion, we have chosen five best manufacturers that we have used ourselves and that are recommended by users:
- Bosch. One of the best manufacturers of blade discs for trimmers. Generally speaking, it is the paddle blades that are more common than the toothed blades. That’s probably because most mowing equipment is underpowered. Some models have the ability to change just one blade without replacing the entire blade.
- Husqvarna. All kinds of blades for grass and bushes, brush cuttings, hay cutting. The quality of the discs is top-notch. The price is a bit steep, though.
- STIHL. There are a lot of bladed blades and serrated blades. The discs are made of high quality steel, do not blunt for a long time, even in contact with the ground or hard objects. About the same price as the Husqvarna.
- Rezer. The company produces a lot of discs for cutting brushwood and bushes up to 60 mm in thickness. But of the discs of this brand is better to take toothed from 40 teeth and more, otherwise the nozzle will wind the grass.
- Champion. Here are some good discs for a reasonable price. If you have no possibility (or desire) to pay more, but want a normal disk, that won’t die after the first stone, the Champion hose nozzles are a good choice.
What brushcutter blades do you use?? Share your experiences in the Комментарии и мнения владельцев?
Advantages of trimmer blades vs
Trimmer disc compared to cord, has its advantages. To know these advantages and benefits is the ultimate decision as to whether to buy and use metal cutting blades. Let’s consider all the advantages of trimmer discs:
- The ability to cope with a variety of vegetation, unlike a fishing line. It can be dead wood, long and thick-stemmed grass, and even small vegetation. The trimmer line is barely able to cut medium-sized grass, and it is not able to cut thick-stemmed grass. Cord will either get tangled up in the grass, or the trimmer line will wear out quickly, which is not at all rational
- High speed of results. Unlike the fishing line, the disc in one pass cuts the grass qualitatively (with a good sharpening), leaving no “roosters”, so mowing with a trimmer with a metal disc is faster than when using cord
- Discs do not wear out, unlike filament. Cutting blades or parts of the circle are blunt, but the issue is resolved by sharpening. How to sharpen a metal trimmer disc, described in the material below. Cutters wear out over time, but will last at least 3-5 years
- Long service life, unlike a fishing line, which is due to the design of the equipment
There are also disadvantages to the cutting devices for trimmers under consideration. The first disadvantage is that you cannot mow with the disc, if it is placed near obstacles like trees, buildings, rocks, benches, etc.П. When the disc collides with an obstacle, the drive brakes, which is reflected in the form of such disadvantages:
- The motor overheats
- The cutting parts of the disc are damaged and become blunt
- Transmission mechanisms. Flexible and rigid shafts (gearbox). Fail
If you plan to mow dense grass in the field, you can’t do without the grass trimmer with a metal blade installed. The trimmer line is used for mowing small grass around obstacles in the yard.
This is interesting!Steel discs cannot be used on trimmers with a curved boom design for safety reasons. If the disc collides with an obstacle, there is a recoil effect, through which the cutting part can get under the feet of the operator. As a result, the operator risks serious injury.
Advantages and disadvantages of toothed disc
Metal toothed discs are circular in shape, with multiple teeth along the edges. The teeth themselves can be of different types, have different shapes and sizes. The more teeth, the better the device does its job. And the tasks of the toothed type include mowing dense thickets and even small trees. The advantage of such parts can be attributed to the fact that the grass trimmer with them picks up speed faster. At the same time, the moment of inertia also increases, which negatively affects the driving device, and it fails faster, because the motor overheats and often stops.
This type is also divided into two types. Peoriated, that is, with holes in the disc itself, and the usual monolithic. The first ones do an excellent job, but have a high price. The latter are much cheaper, but have a significant disadvantage. Their weight. Because of their monolithic metal construction, it’s not recommended to put them on grass saws with an engine displacement of less than 30cc. The mechanism simply won’t take the load.
How to insert a fishing line into the grass trimmer for trimmer?
There are 2 common ways to wind the cutting cord on the grass trimmer spool, which depend on the type of mowing head. To choose the right method, you need to study the design features of the bobbin. This will help you understand how to insert the cutting cord into the trimmer spool faster and easier.
How to wind the trimmer line on the grass trimmer spool. The first way
In the first type of heads, the separating edge between the upper and lower compartment has a recess and does not close into the ring.
The line for the trimmer is wound on such spools in the following order:
- First you need to cut a 6-meter piece of cord from the common coil. The resulting section must be bent in half. As a result, one side of the fishing line should be 15 cm longer than the other;
- The cord, where it is bent, must then be inserted into the notch provided on the edge between the upper and lower compartment of the coil. As a result, one part of the cord should be in the upper compartment and the other part in the lower compartment of the head;
- Then start winding the cord onto the grass trimmer. Do this only in the direction that the arrow on the spool indicates. The cutting filament should not be intertwined and the lower and upper parts of the cord should be wound into the corresponding compartments of the bobbin. After that, 15 cm of free cord should remain in each compartment;
- There are notches in the upper compartment of the spool, which are designed to hold the fishing line in place. The ends of the filament should be hooked into these slots so the filament is stacked up against each other;
- The operator must then assemble the mowing head and install it on the grass trimmer.
Before operating the brushcutter the operator should pull the free ends of the brushcutter filament out to put some tension on them. Thanks to this, when mowing grass, the line for the trimmer will feed evenly from the bobbin, without holding the operator.
How to tuck the trimmer line into the grass trimmer spool. The second way
In the second type of spools, the separating edge is one piece. On both sides there are notches through it, which are designed for winding new fishing line.
To install the cord on such a head, the operator must act in the following order;
- The previously prepared 6-meter piece of cord must be bent exactly in half and cut. The operator should then have two identical pieces of wood;
- Then at the end of each of the pieces will need to make a small hook;
- Next, the hook of one of the line section for the weed trimmer will need to be inserted into the hole located at the top of the head;
- After that, you can start winding the cord. This is done strictly in the order that the arrow on the bobbin indicates. The cord being used should be wound evenly on top of the reel. As a result, about 15 cm of cord should remain free;
- The remaining end of the line will need to be secured in the notch at the top of the bobbin;
- Wrap second piece of cord around bottom of grass trimmer’s mowing head in the same way.
This method is suitable for all types of cords, including homemade line from a plastic bottle.
What models and brands are in high demand on the market?
- A disc from the German manufacturer Huter, made of alloy steel.
- Blade 3T-GDT with three knives. Diameter 255 mm. Can be sharpened.
Great for small yards. Can be used regularly as required. Has protective anticorrosive coating. Weight does not overload the engine. Only one disadvantage, it requires a powerful gasoline tool.
How to Cut Grass with String Trimmer
Compatible with all existing standard trimmers. Capable of mowing hard weeds, working in limited areas (in terms of accessibility and area). Increased wear resistance.
Blade 10002. Simple and sufficiently effective in operation. A tool for home use. Can be installed on many trimmer models.
Available with standard bore diameter. That allows its use on the vast majority of models of gasoline and electric trimmers. Has corrosion protection, regrindable. Keeps its efficiency after collision with hard obstacles.
Four Blade 38740 works well on dense grass. Virtually does not wind up grass. Creates a smooth lawn surface. Can be sharpened. The disadvantages are a high probability of breakage when in contact with solid bodies.
Here it is possible to note russian production of Champion brand. 255 mm diameter three-blade blade made of hardened plastic, model C5157 HT48 “Maxi-Cut.
Heavy-duty plastic mows weeds and wet grass perfectly. Universal product adapted for operation with most existing trimmer models.
The leader of this segment is the Norwegian brand Husqvarna, with the model 5784445-01, made of alloyed steel. Has three blades and a diameter of 300 mm.
Designed for mounting on powerful chainsaws. Characterized by high quality, factory-made sharpness and long service life.
The right choice of these consumables. As discs for trimmers, allows you to significantly increase the quality of work with a reduction in time of its performance.
If you have the financial resources, the best solution is to buy a powerful universal tool that can solve the whole range of tasks, and complete it with several different discs, which are designed to perform specific operations. It is desirable to use products of famous brands.
Where and what is the best knife?
When the capabilities of the fishing line are not enough, it is worth thinking about replacing it with a steel or plastic knife. If the trimmer comes with a replacement blade, there are no problems: replacement of the cutting equipment is made in accordance with the instruction manual for the grass trimmer. But this is not always the case.
Find out the suitability of the installation of the blade on the existing electric trimmer for grass (with gasoline such problems will not be) can be on the actual number of revolutions of the flexible shaft. If when replacing the bobbin with a line on the knife, the engine picks up the set number of revolutions in a second or less, then the replacement is possible, otherwise the engine will overheat a lot, and the gearbox of the grass trimmer will quickly fail.
It is interesting to compare the three most common variants of blades. Multi-tooth disc, as well as with two and three blades.
Metal disc knives
Usually the trimmer comes with several such knives, but you can buy them separately, measuring the outside diameter of the knife and the configuration of the planting hole. For example, STIHL and Husquarna circular blades are interchangeable. Disk knives differ in the number of teeth, height (can be different height), as well as the solidity of the blade. These knives are most often installed on trimmers from STIHL, Huter, AL-KO, equipped with a straight boom, and are the most rigid. They are good for old growth and long stems, but young grass often causes sticking of the mowed material on the inner surface of the blade guard.
Grass trimmer with a perforated blade, compared to a solid blade, picks up speed faster. A disadvantage of circular blades is the higher moment of inertia, which increases the starting power of the drive. On cheap designs and with frequent stops in operation, this leads to overheating of the engine and adversely affects its durability.