Features of using a machine for sharpening a circular saw. Sharpening circular saw blades

The process of building private houses and various buildings will be quite complicated without the use of a circular saw. It is much better than many saws for wood, because it surpasses them in accuracy and cleanliness of the cut.

Due to the fact that this tool is actively used, it wears out quite quickly, and therefore sharpening circular saws with your own hands becomes extremely necessary.

What you need to sharpen circular saw blades

First of all, you need to prepare the appropriate components that will allow you to properly sharpen the saw blade for wood. It is important to provide the following tools:

file;
mounting vice;
wooden bar;
colored marker.

How to know when it's time to sharpen your saw blade

The saw blade should be sharpened only when necessary. You can recognize the onset of such a moment by two clear signs. In particular, an urgent sharpening of a circular saw on wood is necessary:

If strong heat regularly occurs on the saw guard in the area of the electric motor. In some cases, with such an increase in temperature, smoke is released under the casing.
With strong pressure on the tool to obtain a good cut in the process of processing the material.
If dark marks appear, traces of soot on the wood and a characteristic smell of burnt wood. This is due to the fact that the saw teeth are blunt.

Varieties of sharpening cutting teeth

For a better understanding of how circular saw blades are sharpened, it is necessary to study the features and structure of those parts of the tool through which the material is sawn. Cutting teeth are the main element involved in sawing wood.

They are made of hard metal. The cutting teeth consist of 4 working flat surfaces: front (a), back (b) and two side planes (c), which have an auxiliary role. By means of one main (1) and two additional (2 and 3) cutting edges, intersection lines are formed for each specified working plane.

Depending on its configuration, a circular saw may have different types of cutting teeth:

Straight tooth type. Often used for accelerated longitudinal sawing. They do not have the ideal cut quality.
Beveled (oblique) type of teeth. They have a characteristic angular edge on the right and left rear surfaces. In some cases, the blades have teeth with different sides of the bevel, which alternate around the entire circumference of the saw. Using such discs, you can cut wood, chipboard and various plastics. A large bevel angle ensures a high-quality cut without chipping on the cutting edge.
Trapezoidal teeth. The cross section of the cutting surfaces have a trapezoidal shape. This configuration allows you to work without blunting for a long period of time. Often the disc has straight teeth, which alternate with trapezoidal. In such cases, the trapezoidal element plays the main role in rough sawing, while with the help of a straight type of teeth, finishing is performed.
Conical tooth type. They have a conical shape. As a rule, they perform an auxiliary function for preliminary cuts on the laminate. The conical type of teeth is used to process the specified floor covering. Such a saw allows you to prevent chips on the material, as often happens when using the main saw.

Video "Sharpening disks for a circular saw"

The process of sharpening a circular saw blade.

The principle and angle of sharpening discs for a circular saw

The working part of the circular saw is sharpened at 4 main sharpening angles. They refer to the main technical parameters of the cutting disc, as well as the type of shape of the cutting teeth.

It is worth noting that all the teeth of a circular saw are characterized by front (γ), back (α) angles, as well as the cutting angle of the front and back surfaces (ε1 and ε2). The value of each specified angle must correspond to the purpose of the sawing devices, the materials to be sawn and the direction of sawing.

In particular, a rip saw is sharpened at fairly large rake angles (15° - 25°).

The indicators of sharpening the front angles for transverse types of cut are in the range of 5 ° - 10 °. Universal options used for processing materials in all types of directions are standardly sharpened at 15 °.

In this case, the value of the specified angle is also influenced by the fact that the cut objects have hardness. Their value has a strict dependence: with a greater hardness of the material that is being cut, the cutting teeth should be less sharpened.

According to the main principle of sharpening teeth on a carbide saw blade, it is important to consider that during long-term operation, the most significant wear processes occur on the upper cutting edges. As a result, with intensive use, their lines can be rounded up to 0.3 mm or more. Regarding the planes of the teeth, it is worth noting that the greatest wear occurs on the front surfaces.

With proper sharpening of the cutting element, such shapes of the cutting edges should be provided in which the radius of their rounding will not exceed 0.2 mm. In this regard, it is recommended to perform parallel grinding of metal on the front and rear planes of the teeth. The use of this method is considered the most appropriate. It is possible to sharpen only one front plane, but in such cases, this operation requires more time. In addition, the teeth will wear off faster as more metal needs to be ground off the rake surfaces.

The standard layer for grinding metal is a value of 0.05-0.15 mm.

How to sharpen a circular saw with your own hands

You can sharpen the saw at home completely on your own. For these purposes, there is no need to visit a workshop to use a specialized grinding machine or purchase one. It is quite expensive, and is used for sharpening in rare cases, unless of course you plan to use it for large-scale production purposes.

But holding saw blades in your hands while sharpening teeth with a grinding wheel is not the best solution. A circular disk is not a drill, it is much larger. No hardness of the hands and an excellent eye will not allow sharpening so that the cutting elements are sharp enough and suitable for effective use. To do this, you need to provide the simplest fixing device.

To hold the gear circular circle in the desired position relative to the plane of the grinding tool, you can use the most ordinary flat stand.

The position of its surface must correspond to the level of the axles on the rear disk. The toothed circle is placed on a stand so that the tooth plane to be sharpened is perpendicular to the blades of the saw blade. To sharpen beveled teeth along the front and rear surfaces, it is necessary to provide movable hinges in this device.

But in such cases it is quite difficult to maintain the same values of the front and rear angles of tool sharpening. To eliminate this problem, it is necessary to perform a rigid fixation of the center of the saw according to the desired position in relation to the grinding wheel. This is done using grooves for the mandrel, which is mounted on a stand with sharpening saws placed on it, or by installing a special stop on the stand, which will fix the saw blade according to the required angle to the abrasive stone.

If you follow all the requirements that apply to sharpening a carbide circular saw, then this tool will work as efficiently as possible over a long period of time.

Video "How to sharpen a saw blade with your own hands"

Demonstrative video on the implementation of self-sharpening of the cutting saw blade.

Sharpening of circular saws is a mandatory measure during the operation of this equipment. Woodworking requires the master to have tools with the appropriate cutting properties at his disposal. Like sharpening chainsaw chains, circular saws require increased attention. If the shortcomings are not eliminated in time, over time the tool will begin to dull much faster.

Saw sharpening is a common activity, as is do-it-yourself chainsaw chain turning. You can entrust the device with hard-alloy, victorious soldering to specialists. This is due to the fact that pobedit solderings have increased hardness, which is why it is impossible to sharpen with an ordinary file. This will require an expensive diamond grinding tool.

The first thing you need to do is determine the current condition of the saw blades. Chainsaw blades and chains show certain signs of wear. If you know about them, you will easily know that the sharpness of the circular saw has deteriorated significantly.

The temperature on the engine cover of your saw blade has begun to rise significantly.
To cut the workpiece, you have to make more physical effort with your own hands. A similar phenomenon is typical for blunt chainsaw chains.
From time to time, smoke may come out of the engine.
When processing blanks, an unpleasant burning aroma is formed.
Dark spots form on the edges of the saw blade. This is soot. It can also appear on the surface of chainsaw chains.
The wooden workpiece begins to move around the machine in jerks, although during normal sharpening the movements should be smooth.
During the operation of the machine, extraneous noise is observed.
The tooth geometry of the saw blades of your circular saw is broken.

General sharpening rules

Photo ways to sharpen circular saws

As in the case of sharpening chainsaw chains, self-sharpening requires adherence to certain recommendations.

Carefully monitor the uniform removal of metal along the profile of the teeth of the saw blade;
Never press the saw blade tightly against the grinding wheel. If the saw sharpening machine is in close contact with the wheel being sharpened, this will lead to overheating and further deformation of the material;
Make sure that the height and profile of sharpening are maintained at the end of the processing operations;
When sharpening discs, use coolant. This is also recommended for those who turn chainsaw chains;
Avoid burr formation when turning the saw blade;
When sharpening the edges, rely on an important rule. It is necessary to sharpen only the front, or the front and back side of the tooth. Although in practice, many do-it-yourself craftsmen prefer to sharpen the saw wheels from the back side, considering this method more convenient;
Products with victorious soldering are sharpened with diamond sharpening devices. Only such tools can really effectively restore the cutting properties of this tool. You can use a regular file, but in fact it will not give the desired effect.

Sharpening methods

You can use a saw sharpener or hand tools.

There are three main sharpening methods, where a specific device is used, and the rules for processing discs are followed. Which of them is the most correct, it is difficult to say. After trying each technique, you can draw certain conclusions for yourself.

Sharpening happens:

classical;
full profile;
Sharpening the edges of the teeth.

We will tell about each of them separately.

classical

This sharpening technique has been used for a long time, which is why it got its name.

Sharpening starts from the back of the disc.
The front part, running on the material during cutting, remains in its unchanged position.
Processing can be carried out directly on the circular saw or the saw blade can be removed by placing it in a vise.
If you sharpen on a circular, be sure to unplug the machine from the power supply.
To fix the disk, use a pair of bars that will secure the circle like wedges. The bars should be tightly pressed against the product in order to prevent its movement during turning.
With a felt-tip pen, mark the first tooth where you will start.
Perform a certain number of movements on the first tooth with a grinder. Remember their number.
For all subsequent teeth, repeat movements similar in number and intensity.
Upon completion of sharpening, be sure to check the performance of the saw updated with your own hands. If there is no extraneous noise, vibrations and the disk machine behaves stably, you managed to do the job correctly.

Alternative Solutions

Alternative sharpening methods include the two methods that we described above. They are quite effective, therefore they are often used by masters.

Full profile saw blade processing. Among all turning methods, this method can be considered the most accurate and high quality. This is due to the fact that specialized grinding machines are used for full-profile sharpening. A special circle is selected in size and in one go passes the entire cavity between the teeth of the disc, while capturing the surface of the adjacent cutting edge. This technique of turning saw blades avoids the possibility of deformation of the tooth circle. The only downside to the sharpening method is that you will need to use the appropriate different wheels to process saws of different profiles.
Teeth edge turning. The popularity of this method of turning circular saw tools is due to the fact that it can be used at a professional level and in ordinary home conditions. If sharpening is carried out using a machine, you will need to purchase the appropriate abrasive wheels that match the parameters of your saw blades. But it is optimal for most owners of circular saws to use the home processing method. This is due to the fact that often it is not required to carry out a large amount of work, and all processing of the cutting edges is carried out with a needle file. To effectively sharpen the product, sometimes it is enough to carry out 4-5 movements with a high-quality needle file. So the teeth will acquire the necessary degree of sharpness.

Experience is a useful thing, thanks to which you can avoid a number of mistakes that are common for beginners. Therefore, paying attention to the advice of specialists is very useful if you want to achieve a positive result for yourself when turning a circular saw.

Always use safety goggles. For some reason, many people ignore this rule, because of which the masters themselves suffer later. Therefore, before starting sharpening, be sure to put on all the necessary protective equipment;
Do not attempt to remove more metal than required. Remove only enough to remove all existing cracks, burrs and bumps;
During turning, be sure to keep the disc in the same position;
If the disc has not been sharpened for a long time, you will have to remove a larger layer of metal;
Observe the identity of all teeth in shape and height.

Initially, it seems that sharpening is a technologically complex process. But with a little experience, you can easily sharpen circular saw blades.

A circular is a device on which work is carried out with building material. As a rule, a tree is processed. A toothed disk is used as a cutting tool. Over time, he dulls. Sharpening a circular saw blade is carried out both on a special machine and with your own hands at home.

Sharpening circular saw blades is required when work becomes impossible. This can be understood by three signals:

Protective cover heating. Smoke appears from under it, exits the cutting zone.
The need for additional effort when feeding the workpiece at the time of cutting.
When wood comes into contact with cutting metal, burning and smell appear.

Types of teeth

The main cutting element of the disc are the teeth. They are made from hard metal. The tooth consists of four sides: anterior, posterior and two lateral. Also from the main cutting edge and two additional ones.

Teeth requiring sharpening are divided into:

Direct. Are applied to longitudinal sawing of a cloth.
Beveled. They have an angle cut on the back plane of the tooth. They can cut not only wood, but also plastics or chipboard.
Trapezoidal. In cross section, the cutting plane has the shape of a trapezoid. Thanks to this, they can be sharpened less often.
Conical. They have the shape of a cone.

Sharpening angles

A circular saw has four corners which, after blunting, must be sharpened. These are the front and back corners. Also the cutting angles formed by the front and back surfaces.

Depending on the direction of sawing, they are needed. In longitudinal cutting, the value of the front angle is in the range of 15−25 degrees. In the case of cross cutting, the grinding angle is reduced to 5-10 degrees. If universal cuts are required, then the tooth is sharpened at an angle of 15 degrees.

An important influence on the value of the angle is the density of the material. The lower it is, the sharper the tooth is required. If the material being processed is plastic, then the angle can be negative.

Sharpening circular saws with pobedite soldering

The sharpening angles of carbide-tipped saw blades are not easy to maintain because the tooth is applied to win. This alloy is attached by soldering. The geometry of the cutting part is complex, and the sharpening parameters require precise exposure.

The work is carried out when the cutting edge is smoothed to a radius of 0.3 mm. A larger value should not be allowed.

Sharpening is carried out on the front and back planes of the tooth. If the work is carried out correctly, then the total number of sharpenings until the blade is completely worn out will be 30 times.
Start work from the front plane.
The part of the tooth that is soldered should fit snugly against.
Turning time is 3 to 5 seconds. It can't be longer. This leads to excessive heating of the metal. It is reheated and tempered with a decrease in hardness.
The thickness of the material to be ground is around 0.15 m.

Machine Application

The simplest machine for working at home is is an abrasive motor. Wheels can be diamond, elbor or silicon carbide.

It is difficult to keep the canvas in a certain position relative to the abrasive. You need to use the tools. This may be a horizontal stand or a fixing device, where the upper plane must coincide with the axis of the abrasive.

The tooth to be sharpened is positioned on a plane so as to be perpendicular to the blade. After turning on the engine, the canvas is brought to the circle and pressed against it with a tooth. The layer of the removed metal is regulated by pressing force. Having finished work with one tooth, the next one is brought up in the same way. And so on in a circle to the end.

For the purpose of universalization, the stand is modernized. The front part is made movable, and a pair of bolts is screwed into the back. With their help, you can adjust the inclination of the canvas. It becomes possible to sharpen the front and back plane of the oblique tooth.

There remains the problem of maintaining the same angles of front and rear sharpening. To do this, it is necessary to fix the canvas relative to the center of the abrasive wheel. To do this, the disk is inserted into a special mandrel, and a groove is made under it in the stand. The necessary is maintained by moving the mandrel along the groove. If the diameter of the discs is different, then it must be possible to move the engine or stand with a groove.

Another way is to install stops that will fix the desired position of the disc.

Sharpening by hand

In the absence of a machine, sharpening can be done with a file. To do this, it is important to clearly fix the disk. This is done with a vice. If the canvas is not removed from the circular, then you can do without them. Bars are inserted between the teeth, and the tool rests against a vertical plane.

A mark is made at any point of the circle with a marker. This will make it clear when the work is completed. Processing is carried out with a flat file, which fits well between the teeth. The upper edge of the tooth and its front face are subjected to the greatest wear.

First, work is carried out with the back surfaces of the teeth around the entire circle. At the second stage, they begin to sharpen the front edges. It is important to remember that the applied force must be the same, then all the teeth will be evenly sharpened.

It is really possible to sharpen a circular disc at home. To do this, it is better to purchase a simple machine. In his absence, you can use a vice or homemade stops. At the end of the work, check the tool. In the process of cutting, his work should be smooth and quiet.

During prolonged use, carbide-tipped circular saw blades may lose their original qualities. But this does not mean that you should purchase a new cutting tool. In most cases, sharpening can be done at home using any suitable machine.

The need to sharpen the saw

First you need to decide whether you need to sharpen or not. There are several clear signs indicating the relevance of this procedure. If you ignore them, then in the future the disk may become unrepairable and will cause the failure of an expensive machine.

The advantage of using a brazed saw blade is to increase the service life. It is also designed for processing hardwoods. Surfacings are made of steel 9HF, 50 HVA, 65G and similar compositions. They are highly durable, but with significant use, the likelihood of their breakage will increase.

Timely sharpening of circular saws with a do-it-yourself machine is performed with the following obvious signs:

increased load on the engine. The reason for this is the deterioration of sharpening and, as a result, the power unit needs more power to cut wood. If the motor design does not provide for protective relays, it may fail;
degradation of cut quality. The first sign is an increase in the width of the cut, as well as the formation of chips and irregularities along its edges;
increase in processing time of the workpiece. It takes longer than usual to form a cut.

The best way is to periodically check the condition of the soldered wood disc. To do this, you will need to temporarily leave the machine and dismantle the cutting tool. If its geometric parameters do not match the original ones, sharpening is necessary.

How to determine the sharpening angle of a circular saw

The best option would be to have an initial template, according to which you can correct the geometry of the cutting edge. Often it is made of thin-walled stainless metal, less often - of thick cardboard.

Carbide teeth are manufactured in accordance with GOST 9769-79. But their geometry and geometric dimensions are determined by the manufacturer based on the purpose of the saw. If there is no template, you must independently determine the required sharpening angles. To do this, it is recommended to use a pendulum goniometer.

Do-it-yourself template manufacturing technology.

Take a new soldered disk, which is completely identical to the blunt one.
On a solid sheet of cardboard, draw precise contours.
Using a pendulum goniometer, determine the initial geometry of the carbide tipped.
Enter the data on the template.

In the future, it can be used for self-sharpening on the machine or provided as a sample for companies providing similar services.

Additionally, it is recommended to compare the obtained data with the reference ones. In rip saws, the rake angle is typically 15°-25°. For transverse models, this figure ranges from 5° to 10°. In universal models, the rake angle is 15°.

It is important to remember that the rake angle can be negative. Similar models are used for cutting plastic sheets and non-ferrous metals.

Methods for sharpening circular saws

Any sharpening machine can be used to form a new cutting edge. It is important to initially choose the right emery wheel and use it to sharpen the edge. To do this, you must use corundum or diamond models.

The best option is to use special equipment designed to perform this work. But due to its high cost, in many cases its acquisition is impractical. An alternative way is to use a grinding machine with the ability to change the angle of the corundum disk.

In no case should you do the sharpening by hand yourself. First, it will take a very long time. Secondly, the result obtained will not meet the standards. If it is not possible to sharpen the saw blade on wood on your own, it is recommended to use the services of specialized companies.

Do-it-yourself professional sharpening of circular saws is carried out according to the following rules:

the main deformation occurs at the upper edge of the tooth. The edges are rounded from 0.1 to 0.3 mm. It is from this place that you need to start processing;
sharpening is carried out along the front and rear edges. This will provide the possibility of repeating the procedure up to 25 times;
the amount of removal should not exceed the value of 0.05-0.15 mm;
the level of processing of the front and back faces should be the same.

After the sharpening of the wood discs is completed, it is recommended to finish it with fine-grained sandpaper. This can be done manually or with a special machine.

Experts advise the use of special corundum discs, the end surface of which has a groove of a special shape. It will make the process easier.

Ways to increase the life of saw blades

The process of forming a new cutting edge is laborious and long. Therefore, it is recommended to fulfill a number of conditions to increase the life of the disk.

Hard solderings have a long service life. However, they are more likely to chip and break off. Alternative soft is practically not subject to such defects. But its service time is less than that of a solid one.

The appearance of roughness on the cutting surface is not allowed. In the future, they can lead to the appearance of chips and cracks.

The video shows an example of a do-it-yourself disk sharpening machine:

Drawings and tooth geometry

Sharpening of circular saws must be carried out clearly in compliance with the norms and requirements for the geometry of the teeth of each individual blade. To properly sharpen a circular saw with your own hands, you need to know the shape of the tooth and its geometry.

A circular saw (the modern name is a circular saw) is a much more effective tool in comparison with reciprocating, longitudinal and chain saws. The quality of the cut and the convenience of work are beyond doubt. With the help of a circular saw, you can perfectly evenly cut a workpiece of a large area, make cuts at different angles and work with a variety of materials.

The circular saw allows you to cut the material both along and across the fibers with the same accuracy and quality. Of course, you can get a clean cut only with properly sharpened teeth. Circular saws fall into three categories:

All-metal
All-metal with spraying of hard materials in the working area
Carbide-tipped saw blades

The presence of technological grooves on saw blades is very important

A lot of force is required to advance the workpiece during sawing.
Chips, cracks appear on the cut
The drive motor becomes very hot during operation
There is a smell of burnt material
Dark traces of overheating are visible on the edge of the cut

In addition, the sharpness of the teeth can be checked tactilely and with a magnifying glass. The radius of rounding of the cutting edge should be within 0.1-0.2 mm. When sawing workpieces of large thickness, not only the main working edge is subjected to wear, but also the side ones.

IMPORTANT! When working, always use the right disc for the material. Otherwise, you will mistakenly send a working disk for sharpening.

General rules for sharpening a circular saw

The discs are sharpened a limited number of times. With each procedure, the size of the tooth is reduced. Sooner or later, the tooth grinds down to a critical value, after which the use of the disc will become impossible.

IMPORTANT! It is unacceptable to work on a blunt disk. In addition to deteriorating cut quality, sharpening excessively dull teeth will require more metal to be removed.

In order to extend the resource, sharpening is carried out along two working surfaces of the cutting edge. In this case, the thickness of the surface to be removed is halved.

Schematic representation of the correct sharpening of teeth

If you do not violate the processing rules, sharpening can be done up to 25 times. Before sharpening, the disc must be cleaned of dirt. Mechanical processing is undesirable, it is better to use washing liquids containing solvents in their composition. The standard amount of removal of the tooth surface is 0.05-0.15 mm.
Sharpening angles are individual for each disc, and are indicated in the passport or directly on the sidewall.

Saw blade marking with sharpening angles

For sharpening discs, there are special ones that mechanically control the selected angles for each tooth. Depending on the intensity of use, the grinder can have an automatic or manual drive. At home, as a rule, inexpensive models are used in which the disc is rotated to the next tooth and the thickness of the metal being ground is controlled manually.

In such devices, the disk is fixed perpendicular to the grindstone, the angle and pitch of the tooth are set. The master runs the sharpened surface on the grindstone a fixed number of times and moves on to the next tooth.

Grinding discs are made of CBN, silicon carbide or use diamond coating. It makes no sense to talk about the fundamental advantage of one material over another. There are only application features. For example, diamond whetstones are capable of cutting harder teeth but are sensitive to overheating.

You can sharpen manually, using a high-quality file. It is better to leave the disc in the machine. The first tooth is marked with a marker, the disc is fixed with wooden bars, clamps or a vice. A fixed number of file passes must be made on each tooth surface. Then rotate the disc by one tooth and repeat the procedure.

How to sharpen a circular saw with your own hands video

Sharpening carbide-tipped discs

Many home craftsmen are faced with the problem of sharpening discs with victorious soldering. If you sharpen with standard abrasives, you have to carry out the procedure longer, and the material can “release” from overheating. Diamond grinding wheels do a much better job, but they are too expensive. Sometimes it is more profitable to buy a new victorious disk.

The choice is up to the owner of the saw, but the general advice is as follows:

When sharpening discs with victorious soldering, in any case, you will have to use the machine, regardless of its technical level. If you have such a machine, purchase a diamond abrasive and sharpening disks of any hardness will not be a problem. If there is no machine, it is better to contact a specialized workshop to sharpen discs with victorious soldering.

You can spend money on the purchase of equipment of any complexity, the main thing is that it does not stand idle, and is in demand. For large volumes of work, it is more profitable to have your own grinding machine for circular saws. If you only perform periodic repairs, it is cheaper to contact the workshop.