How to put the blade on the grass trimmer

Rules for replacing grass trimmer blades

If the disc on the trimmer is used regularly, it needs to be removed and sharpened or replaced with a new one from time to time. This part can be made of metal or plastic, have a different number of blades, but the replacement process remains the same. over, this procedure is similar for equipment from different manufacturers, whether Carver or Huter, but there may be minor differences. Changing the blade on the trimmer is simple enough, if you follow the safety precautions and know the correct procedure, a description of which can be found in the user manual. The entire replacement process will be described in this brochure, step by step, as well as the method of sharpening the blade yourself.

When using a brushcutter on dacha plots, the most popular attachment is a line for the trimmer. It is inexpensive, suitable for different trimmer heads, safe to use. The disadvantage of using a fishing line is that it is only useful for mowing low growth. In other situations, the string is immediately clogged, regardless of whether a gasoline or electric grass trimmer model is used. This greatly reduces the risk of injury from cuttings being wrapped around the spindle, causing considerable resistance to the shaft and damaging it. It can also cause the piston system in chain saws to malfunction or the motor in electric trimmers to burn out.

This is why different attachments are used for mowing tall or tough vegetation. So, for cleaning tall and coarse grass, thin shoots of trees and bushes, it is better to install and activate the disc. This attachment is much less likely to get clogged, which makes the machine more resistant to wear and tear.

For your information! Due to the fact that the motor of electric trimmers and cordless models is less powerful than that of gasoline mowers, so the use of discs is more relevant for gasoline mowers.

Which cutter is better?

Modern manufacturers offer the consumer a wide choice of disc varieties. The cutting parts are classified according to the following criteria


The material for the blades is plastic or metal, which determines their purpose. There is a legitimate question about what kind of disc is better to use: plastic or metal? The choice is determined by such factors:

Three-blade plastic blade for an electric grass trimmer

In terms of safety, steel cutters are not recommended for electric lawn trimmers. they are almost always equipped with plastic blades. The peculiarities of the design of the electric tool itself, its technical characteristics make the installation of metal cutting parts dangerous:

Plastic blades are only used on mowers with a flexible shaft, according to the rules of safe usage. Plastic blades are designed for mowing soft plants (e.g. burdock, nettles), dead wood. Metal disc mower is used for cutting dense, tall and rough grass, bushes and shoots of different trees, because its cutting properties and wear resistance are better than plastic analogues.

Grass trimmer cutter with 40 tungsten carbide inserts

The design and specification of these machines usually require the use of metal cutting heads:

  • straight boom increases leg distance to the hedge trimmer;
  • comfortable handles with stops;
  • Smooth speed setting ability.

Gasoline units equipped with metal discs are well suited when you need to mow large areas with a variety of grass or shrubs.

Number of blades

The shape of the blades of discs has practically no effect on the quality and speed of work, it is their number that counts. For haymaking, the use of cutters with more blades is recommended, for example, 8 or 4 main and 4 auxiliary blades. If there are few of them (2, 3), such blades shred the grass very strongly. Cutters with a large number of fine tines are used for mowing young shoots of trees and shrubs.

Patriot PT453 lawnmower with metal disc for mowing shrubs

Metal blades for lawnmowers are sharpened in different ways: on one side and on both sides. Dull or badly sharpened cutter edges reduce productivity and lower quality of work. The strain on the tool and fuel consumption increases.

Collision of blades with stones is dangerous, because the tool bounces off and can injure the mower.

Choose a cutting element for grass trimmer by material, size, design should be based on the type of tool and its engine power, the amount of work to be done and the type of plants to be mowed. Partly help in this is the manufacturer’s manual to the model used. there is written there the recommended parameters of the cutters.

How to use a trimmer: useful tips

Grass trimmer is a device through which you can do many things related to facial hair. It is perfect for beard trimming, eyebrow corrections, nose and ear hair removal and even in the bikini zone it is at its best. But how to properly use such a device for maximum efficiency?

When shaving, there are certain peculiarities to consider:

  • the grass trimmer must not slip on the skin, otherwise cuts are unavoidable. The device should move smoothly on the skin, but the slip here will play a disadvantage, unlike a razor.
  • Finding the right attachment for the right purpose is key to a comfortable and successful shave.
  • If the grass trimmer is not waterproof, you should only shave on dry skin/hair. If you ignore this advice, you will not get a good shave: the efficiency will decrease significantly, regardless of the quality of the model itself.
  • When using the device for shaving or grooming (shaping, grooming) beard, the latter must be kept clean and do not neglect hygiene. The ideal solution would be to wash your beard every day along with the rest of your body.
  • You should be careful, because the length of the nozzles can be different. With the shortest possible haircut, if a pimple accidentally pops under the beard, the blades of the device can easily cut it. If you have any reasonable concerns, start with the safer length and switch to the shorter length after testing your skin for rashes.
  • The use of moisturizing creams negates the usefulness of the device because of the aforementioned slip. It is best to wash your beard, mustache, etc. thoroughly. д., Let it dry well, and only after that should you start trimming or shaving with your trimmer.
  • It is better to use softening shampoos/conditioners when washing your beard. This will make the hair supple, and it will be much easier to shave.
  • When shaving, move slowly and always against the growth of hair (unlike with a razor again). Grass trimmer often needs several passes over an area of skin to shave all hair clean.
  • Never forget to lubricate the head before shaving with the oil included in the shaving kit. Without this, the likelihood of cuts increases significantly, and the effectiveness of the grass trimmer decreases rapidly. The durability of the device is also decreased. Blades and motor should always be lubricated, otherwise the life of the grass trimmer will be significantly reduced.
  • Always use the special brush that comes with your shaver to wash and clean it perfectly afterwards. Hairy debris stuck in the blades is bad.
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Proper use of the device consists in strictly following the basic rules of shaving with trimmers. If these conditions are met, the rest of the shearing process is entirely up to the individual. So, the trimmer shaving procedure is as follows:

Before you start the shaving process itself, you should oil the head of the device. This can be done horizontally, along the length of the entire head, and vertically:

The main thing is to get the oil on the blades. Wipe off the excess with a dry soft cloth. A few drops will be more than enough.

If the trimmer for grass, according to the instructions, do not need to lubricate before direct shaving, it should be done after the end of work and cleaning of the device. Details should be clarified, again, in the manual to the device, t. к. they come in different.

After you should turn on the device for 15-20 seconds, so that the blades are evenly lubricated. After turning off the grass trimmer, it is necessary to wipe the blades dry, so that the remaining oil does not stick to the trimmed hairs.

And now it’s time for the most important part, the shaving process with the trimmer. Important note: use it upside down, i.e. from bottom to top, to cut hair in the opposite direction to the hairline.

If you have a goatee or a goatee equivalent, you should shave your cheeks. For best results, the smooth part of the device should be placed against the skin. so the hair will be shaved as well as possible. No nozzles should be used for this.

If there is a beard of a certain length, it is wrong to immediately start shaving without attachments.

You need to cut the hair in order of priority, starting from using the nozzle (for long hair), gradually moving to shorter hairs (, then ).

Parts of the skin can be shaved completely free of hair without attachments (including removing the zero stop). This way, it is possible to achieve a 5 o’clock bristle effect.

Depending on the model of grass trimmer you choose, you can achieve very different results. Right down to the hair, which is almost invisible to the touch. In other words, it can replace your razor if you’re happy with the results.

Here everyone decides for himself what kind of beard he wants and how to achieve the desired result:

  • To give a rounded beard, use a zero head and gently trim the hair to suit your needs or beard type;
  • for the “goatee” effect first need to shave the hair to the desired length, and then use the attachment to shave the hair, creating the desired shape beard (after the basic shaving of the remaining areas trimmer without attachments can trim beard).

There are many variations in the use of the grass trimmer. But it is simply impossible to describe each case and how to use the device more correctly in each case. Following the rules of trimming (shaving against hair growth, etc. п.) remains the key. Otherwise, the owners of the device are free to decide how the shaving procedure will be carried out.

If you want to shave a mustache, you should do it with a trimmer without the attachments. It’s enough to smile slightly with your mouth closed and shave an area of skin along the straight line of your lip. This is done by a sharp part of the trimmer for grass (for convenience it will be better to hold the device upside down) from bottom to top:

Men and women can use a trimmer for grass for the bikini zone, but for this you should buy a suitable model in advance. Grass trimmers for beards are not suitable for the bikini area, as well as vice versa, due to the difference in the structure of the devices. Yes, and they have slightly different purposes.

Safety rules

Among the safest and most popular trimmers are especially valued products of German manufacturers (including Denzel), as they pay great attention to quality and reliability. However, despite the brand and model, there are a number of rules that should be clearly known and followed when using a grass trimmer.

  • Before using it, you should read the instruction manual.
  • Do not work with the trimmer in a state of fatigue, illness, intoxication.
  • It is forbidden to use the scythe in explosive and fire-hazardous areas.
  • Do not mow during thunderstorms and rain, or after rain when the grass is wet.
  • Work only during daylight hours and in good lighting conditions.
  • Only use the type of fuel and lubricant that is suitable for the particular model of grass trimmer.
  • It is not advisable to repair the tool yourself.
  • Do not touch rotating or heated elements during operation.
  • Do not smoke or light fires when mowing, etc.д.

Important! The grass trimmer may also be subject to other health hazards: excessive noise and vibration, exhaust fumes, high temperatures of certain parts, flying branches, etc. To minimize risks, overalls, goggles, and ear defenders should be worn.

If there are still questions about the adjustment on the belt-backpack of a particular model of brushcutter, you can try to find the answers in the instruction manual that comes with the product, or watch a video on the Internet, where it is clearly and affordably shown how to adjust and adjust the belt together with the gasoline brushcutter.

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Where and what is the best knife?

When the capabilities of the fishing line are not enough, you should consider replacing it with a steel or plastic blade. If the trimmer comes with a replacement knife, 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.

Check the suitability of the knife installation on the existing electric trimmer for grass (with gasoline trimmer such problems will not be) can be measured by 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 grass trimmer will quickly fail.

It is interesting to compare between the three most common variants of blades. multi-tooth disc, as well as with two and three blades.

blade, grass, trimmer

Petrol Strimmers Head Replacement

Metal disc knives

Usually the trimmer comes with several such blades, but you can buy them separately by measuring the outside diameter of the blade and the configuration of the seating hole. STIHL and Husquarna circular blades, for example, are interchangeable. Disc knives differ in the number of teeth, height (can be different heights), as well as the solidity of the blade. These knives are used in STIHL, Huter, AL-KO trimmers with a straight boom and are the most rigid. Handles old growth and long stems well, but young grass often gets stuck on the inner surface of the blade guard.

blade, grass, trimmer

the grass trimmer with a peorized blade, in comparison with a solid blade, picks up speed faster. Disk knives have a disadvantage. higher moment of inertia, so the starting power of the drive is increased. With low-cost designs and frequent work stoppages this leads to overheating of the motor and adversely affects its durability.

Putting a CIRCULAR saw blade on a TRIMMER

Double-blade and triple-blade knives

The Bosch brand of electric grass trimmers comes with such knives. Their moment of inertia is minimal and has little or no effect on the functionality of the drive. The convenience of such design is that each of the blades can be replaced separately. With trimmers of such designs the boom is curved in a form of letter J. Double-blade knives run smoothly on even mowed material. They throw the cuttings well to the side and do not allow the residue to stick or wrap around the shaft of the boom.

Three-blade and two-blade knives are quite competitive with disc knives, but the blade thickness must not be less than 2 mm. Forged knives are more durable than stamped ones (found on trimmers made in China). To distinguish them simply. the stamped blades clearly distinguish the traces of the cut-off punch with the presence of distinctive zones of shearing and chipping, which is not present on forged blades.

Shark knives

“Shark” is a nozzle of three bladed knives, and each blade is fixed relative to the other at an angle of 120°. The advantage of this design is that each blade can be set individually. As a result, when mowing different types of vegetation (grass, weeds, dead wood) the quality of mowing will be approximately the same. In addition, as the interval between each blade is reduced, the grass is ejected more intensively. The “Shark” head is compatible with many sizes of electric trimmers and is notable for its low dead weight, but requires periodic adjustment of the blade, which is fixed to the base with standard screws.

The moment of inertia of the circular blade can be reduced by self-piercing its surface, for example, on a punching press. The holes must be perfectly symmetrical in relation to the center of gravity of the blade. The tool becomes lighter, but its cutting capacity does not change. A positive effect is also given by the correct sharpening of the blades of the replacement knife. It is done at a low number of revolutions of the medium grit grinding wheel. The teeth are sharpened at an angle of 30°. Do not use a grass trimmer blade with a carbide tipped blade. the quality of the cut will remain almost the same, but the weight of the tool will increase.

  • First of all, you should disconnect the electric grass trimmer from the mains, gasoline. just a muffler. Remove the blade guard on one side
  • Then you need to connect the holes in the gearbox and the shaft to insert the pin and lock the drive.
  • If a hair reel was used, it should be turned clockwise.
  • Then you need to find a nut to tighten the blade.
  • The next step is to install the blades. Grass trimmers often wonder which side to put the blade on. This should be done so that the numbers and letters are at the top.
  • Then you need to put the cover on top, and over it. fixing nut, which must be tightened firmly with a wrench.
  • Last step. install the protective cover.

As you can see, the procedure is very simple and the same for many brands, be it STIHL or Husqvarna.

blade, grass, trimmer

Note! If the owner wants to replace the disc with a cable, you can install the spool in the same way.

Disc selection criteria

You need to choose a plastic or metal blade, taking into account the area to be treated and the type of grass trimmer. electric or gasoline. The number of blades will depend on how much growth to remove with the tool. You can select the desired disc shape, number of blades and material using the unit’s instruction manual. It usually determines which cutters are recommended for certain problems.


It is not recommended to attach metal blades to electric lawnmowers, because their constructional features make them dangerous for the user. This is due to the curved shape of the shaft, the lack of locks on the handles and the high rotation speed.

Important! The straight arrow ensures safe use of the grass trimmer at times when the disc rotates against an obstacle. In this situation, it bounces back to the person, so the curved design can cause injury

On flexible bar trimmers For safety reasons, plastic blades should be used. Their purpose is to mow soft grass, dry grass. While metal discs are excellent for tall, dense, stiff shoots, shrubs and tree shoots.

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The number of blades is important for different tasks. Thus, two or three pieces are sufficient for shredding grass

Four to eight blades on the disk are required for the bevel. To destroy small shoots of trees and shrubs, instead of discs should be a large number of small teeth.

Sharpen disc

Regardless of the quality of the disc, over time it will become dull and begin to mow poorly. If the blades are still relatively new and not practical, you can sharpen them yourself.

Important! Sharpening is only suitable for discs that do not have a hard solder. Such parts must be discarded and replaced with new ones

  • Disassemble the grass trimmer, remove the blades;
  • Inspect blade carefully. if cracks are found, it is better to replace the part with a new one, as further work is dangerous;
  • Curved blades can be carefully bent with a hammer;
  • Considering the size of the disc, you need to choose the right file for the metal, this will ensure a more comfortable work;
  • at an angle of 30 ° equally sharpen all upper cutting edges of discs;
  • Assemble the grass trimmer in reverse order.

You can use a low-speed grinder to sharpen the disc, setting the grinding wheel with a medium grit. With this tool, the process will move much faster. For safety it is necessary to wear gloves and a face mask or goggles.

So, for grass mowing, gasoline and electric trimmers use plastic and metal discs of different shapes and with different sets of blades. They are chosen according to the type of work to be done and the size of the area to be treated. If the blades of the mower are dull, they can easily be sharpened or replaced yourself

Despite the simplicity of the procedure, care must be taken and precautions taken to avoid injury due to negligence or damage to the equipment. A more detailed description of blade replacement for a specific model of grass trimmer can be found in the instruction manual or on the official website of the manufacturer

For illustration, the general scheme of the process is shown in the video.

What kind of line to choose for your trimmer

Before you stock up on this stuff to put in the grass trimmer, you need to decide on the choice. After all, the usual so-called round line for the trimmer is not the only type that exists. So how do you choose the right one?? The first thing to do is to determine the working conditions.

Choosing by type. The line for trimmer with a round section is the most common. It fits on all spools with very few exceptions. This kind of material is suitable for mowing fresh, lush grass. But here with the mowing of so-called dead wood, this type can no longer cope. Trying to mow shrubs with this thread is needless to say.

In addition to the usual type, there are others with sharp edges. Usually they are made by “star” or “square”. The presence of sharp edges is the main feature and the key difference between these threads.

Precisely because of this feature, these types of threads are able to mow dry weeds. But pointed threads are not without disadvantages, the main of which can be called rapid wear and durability, noticeably inferior to the round type.

In addition to the already mentioned types of fishing line, there are other interesting and frequently encountered varieties. Among them one can specially note the lines with a metal wire inside. Threads of this type are often used in tools that run on gasoline and have an engine with more than one and a half horsepower.

Yarns with a metal core are available with both round cross-section and with sharp edges. Regardless of the cross section type, such yarns are the best for overcoming hard-to-cut plants. This type of threads can easily mow not only dry grass, but even small bushes.

Filaments with wire inside compare favorably to other types of consumables by their incredible durability. But unfortunately, this feature has more than a noticeable impact on the price of this type. The cost of core threads is much higher than other types of threads.

Some features

To date, industry produces dozens of types of these consumables, and they can be made not only of metal, but also of plastic. There is no need to think that the latter are disposable, because they can be a convenient and durable replacement of the fishing line in those areas where high strength is not required.

How to install the blade correctly on the grass trimmer

Installation of a diamond disc

This operation does not differ in appearance from the attachment of a typical disc, except that even more attention, accuracy and careful control is required.

Remove the spool of fishing line by blocking the reducer shaft with a special pin or a screwdriver of suitable diameter, turning the fishing line container counterclockwise.

Try the diamond disc on the bottom spline washer and make sure that its seating hole is larger than the diameter of the seating belt on the washer. High revs can cause the saw blade to shift and imbalance, inevitably leading to tool breakage and even injury to the operator or bystanders.

Let’s try on the compensating washers one by one and chose the one that will fit to the width and fit through the gap between sawblade’s seat and centering shoulder of lower washer.

Put the lower washer with the wear ring, the diamond disc, the upper washer and the cover plate on the gearbox shaft one after the other to redistribute the clamping force over a larger area.

Tighten the complete set on the gearbox shaft with the nut with left-hand thread, first by hand and then with a socket wrench, blocking the shaft of the gearbox from below with a suitable screwdriver.

Remove the protective cut plastic tube from the teeth and once again check the tightness of the saw blade fastening on the gearbox shaft. If it turned out to be reliable, the grass trimmer, with the diamond disc installed, is completely ready, both for traditional and not intended for this tool, work.