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A circular saw is a steel disk with teeth applied to its circumference, which can be either soldered carbide or directly cut (cut) from the body of the circular saw itself.

Sharpening and finishing of teeth circular saws with carbide tips, they are performed with abrasive (carborundum) or diamond wheels, and also in combination: preliminary (rough) sharpening is performed with abrasive wheels, and finishing sharpening and finishing with diamond wheels. To save carbide and grinding wheels, the main sharpening should be carried out at the expense of the length of the plate - along the rear edge, and auxiliary sharpening - along the front. Sharpening along the back edge consists of sharpening along the steel part of the tooth at an angle of α+6°; finishing sharpening on a carbide plate at an angle α+2°; finishing the part of the plate adjacent to the blade at an angle α. Sharpening along the front edge (if necessary) consists of preliminary sharpening along the entire edge at an angle γ1 of soldering the plate to the tooth and final sharpening along the front edge at an angle γ (during finishing sharpening and finishing). Sharpening and finishing must be carried out with continuous cooling. Bakelite-bonded diamond wheels can be used without cooling.

Diamond sharpening and finishing increases tool life by 2...3 times and reduces consumption by 1.5...2 times hard alloys. Basic rules: sharpening is carried out only on a hard alloy plate (at an angle α+2°), the maximum allowance for sharpening is no more than 0.2 mm; finishing is carried out only along the chamfer (at an angle α), the allowance should be no more than 0.05 mm.

On modern sharpening machines using a combined diamond abrasive tool (two fractions of grains), sharpening is carried out with continuous cooling in one pass while removing an allowance of up to 0.25 mm. Carbide saws have also been developed, which use non-sharpening blades with double-sided sharpening. By rearranging them, they are used on both sides and then recycled to make new sharp plates. This technology fundamentally simplifies the organization of tool facilities due to its centralization and consolidation of special tool enterprises.

Design of the back surface (back of the head) of the tooth. If a cutter has a flat back edge of the tooth and sharpening is carried out along this back edge in parallel layers, then as the tooth wears out, its back angle α decreases and with a sufficiently large number of sharpenings it can become unacceptably small. You can sharpen the tooth along the plane of the back edge, maintaining the value of the back angle. But this will lead to a decrease in the sharpening angle β with a loss of cutter accuracy. To ensure constancy of α, the back edge is sharpened along one of three curves: along an Archimedean spiral, along a logarithmic spiral, along a circular arc drawn from a displaced center.

To ensure normal operating conditions for those sections of the tooth blade contour that lie in the plane of rotation of the cutter or close to it, a side clearance angle is created by means of an oblique side turning of the back of the tooth (tangential undercut by 2...3° or radial undercut by 0°3"...1 °), like the teeth of a planing saw.

Sharpening saws for wood: sharpening saws for MDF, sharpening saws for chipboard. Sharpening saws for composite materials: sharpening saws for plastic, sharpening saws for laminate. Sharpening saws for metal: sharpening saws for aluminum, sharpening saws for steel. Sharpening diamond saws.

Sharpening circular saws

Material and properties of carbide teeth

In domestic saws, sintered tungsten-cobalt alloys of grades (6, 15, etc., the pattern means the percentage of cobalt) are used as the material for cutting inserts. At 6 the hardness is 88.5 HRA, at 15. 86 HRA. Foreign manufacturers use their own alloys. Hard alloys consist mainly of tungsten carbide cemented with cobalt. The characteristics of an alloy depend not only on its chemical composition, but also on the grain size of the carbide phase. The smaller the grain, the higher the hardness and strength of the alloy.

Carbide plates are attached to the disc using high-temperature soldering. Silver solders (PSr-40, PSr-45) are used as soldering material in the best case, and in the worst case. copper-zinc solders (L-63, MNMC-68-4-2).

Carbide tooth geometry

The following types of teeth are distinguished in the form.

Straight tooth. Typically used in fast rip saws where quality is not particularly important.

Oblique (oblique) tooth with left and right angle of inclination of the rear plane. Teeth with different angle tilts alternate with each other, due to the fact that they are called alternating. This is the most common tooth shape. Depending on the size of the grinding angles, saws with alternating teeth are used for sawing a wide variety of materials (wood, chipboard, plastics). both in longitudinal and transverse directions. Saws with a high back angle are used as a trimmer when cutting plates with double-sided lamination. Their use allows you to avoid chipping along the edges of the cut. Increasing the bevel angle reduces cutting force and reduces the risk of chipping, but at the same time reduces the strength and durability of the tooth.

Teeth can be inclined not only to the rear, but also to the front plane.

Trapezoid tooth. A feature of these teeth is the relatively slow rate of dulling of the cutting edges compared to alternating teeth. They are usually used in combination with a straight tooth.

Moving with the latter and slightly rising above it, the trapezoidal tooth performs a through cut and a straight line, following it. clean. Saws with alternating straight and trapezoidal teeth are used for cutting double-sided laminated plates (chipboard, MDF, etc.) and also for sawing plastics.

Conical tooth. Saws with a conical tooth are auxiliary and are used to remove the bottom layer of the laminate, protecting it from chipping during the passage of the main saw.

In the vast majority of cases, the front side of the teeth is flat, but there are saws with a concave front surface. They are used for cross cutting finishing.

Teeth grinding angles

The grinding angles are determined using a saw. those. one for cutting the material and in which direction it is intended. Rip saws have a relatively large rake angle (15°.25°). In crosscut saws, the γ angle typically ranges from 5-10°. Universal saws designed for cross-cutting and longitudinal cutting have an average rake angle. usually 15°.

The grinding angle values ​​are determined not only by the cutting direction, but also by the hardness of the saw material. The higher the hardness, the smaller the rake and back angles (less narrowing of the tooth).

The front angle can be not only positive, but also negative. Saws with this angle are used for cutting non-ferrous metals and plastics.

Basic principles of sharpening

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When sawing massive workpieces, the side surfaces are also subject to rapid wear.

Do not overdrive the saw. Curvature radius cutting edge should not exceed 0.1-0.2 mm. In addition to the fact that when a blade is severely dull, productivity drops sharply, it takes several times longer to grind it than to sharpen a normally dull blade. The degree of dullness can be determined by both the teeth themselves and the type of cut they leave.

Proper sharpening of circular saws must ensure, at the same time, that the cutting edge is properly sharpened to provide the maximum number of cutters, which in the optimal case can be up to 25-30 times. For this purpose, it is recommended to use a carbide tooth, which should be ground along the front and back planes. In fact, teeth can be ground along one front plane, but the amount of possible sharpening is almost half as much as when sharpening on two planes. The picture below clearly shows why this happens.

Last sharpening run saw blades It is recommended to do it on the back plane of the tooth. Standard metal removal value. 0.05-0.15 mm.

Before sharpening, it is necessary to clean the saw from any dirt, such as resin, and check the grinding angles. On some saws they are written to disk.

Equipment and materials for sharpening saw blades

When using abrasive wheels (especially diamond wheels), it is advisable to keep them cool.

As the temperature increases, the microhardness of abrasive materials decreases. Increasing the temperature to 1000 °C reduces the microhardness by almost 2-2.5 times compared to microhardness at room temperature. Increasing the temperature to 1300 ° C leads to a decrease in the hardness of abrasive materials by almost 4-6 times.

How to sharpen saw blades yourself using a simple device

Sharpen carbide disks very easy with the help of a simple device, and such disks times

How to sharpen a saw blade with your own hands

Dull saw blade on my Makita 2704. Finance for the purchase of a disk from Makita or SMT in this moment There is not

Using water for cooling may cause rust on machine parts and components. To eliminate corrosion, water and soap are added to the water, as well as some electrolytes (sodium carbonate, soda ash, trisodium phosphate, sodium nitrite, sodium silicate, etc.), which form protective films. In conventional grinding, soap and soda solutions are most often used and fine grinding is used. low concentrated emulsions.

However, when grinding saw blades at home with low grinding intensity, the wheel is often not used to cool the wheel. not wanting to waste time on this.

To increase the grinding ability of abrasive discs and reduce specific wear, you should choose largest size grain, which ensures the required cleanliness of the surface of the pointed tooth.

To select the abrasive grain size according to the grinding stage, you can use the table in the article on grinding rods. For example, if diamond wheels are used, 160/125 or 125/100 grit wheels can be used for roughing. 63/50 or 50/40. Wheels with grit sizes ranging from 40/28 to 14/10 are used for removing teeth.

The peripheral speed of the wheel when sharpening carbide teeth should be about 10-18 m/s. This means that when using a 125 mm diameter wheel, the engine speed should be around 1500-2700 rpm. More brittle alloys are sharpened at lower speeds in this range. When sharpening carbide tools, using harsh modes results in increased stress and cracks, and sometimes grinding of the cutting edges, while increasing wheel wear.

When using saw blade sharpening machines, changing the relative position of the saw and the grinding wheel can be done in different ways. movement of one saw (the motor with the circle is stationary), simultaneous movement of the saw and the motor, movement of only the motor with the circle (the saw blade is stationary).

Machines of various functions are produced. The most complex and expensive programmable complexes are capable of providing a fully automatic grinding mode, in which all operations are performed without the participation of a worker.

In the simplest and cheapest models, after installing and securing the saw in a position that provides the required sharpening angle, all further operations. turning the saw around its axis (turning on the tooth), feeding it for grinding (contact with the wheel) and controlling the thickness of the metal removed from the tooth. are made by hand. Such simple models It is advisable to use at home when sharpening circular saws is occasional.

An example of the simplest machine for is the system photographed below. It consists of two main nodes. a motor with a wheel (1) and a support (2) on which a pointed saw is mounted. The rotating mechanism (3) serves to change the angle of the blade (when sharpening teeth with a beveled front plane). Using the screw (4), the saw moves along the axis of the abrasive wheel. This ensures that the specified front grinding angle value is set. The screw (5) is used to set the stopper in the desired position, preventing the wheel from excessively entering the interdental cavity.

Saw blade sharpening process

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The saw is mounted on a mandrel clamped using a conical (centering) sleeve and nut, and then installed in a strictly horizontal position using a mechanism (3). This ensures that the front plane inclination angle (ε 1) is 0°. In disc grinding machines that do not have a built-in angular scale in the tilt mechanism, this is done using a conventional pendulum goniometer. In this case, check that the machine is level.

The rotation of the screw (4) of the mechanism, which ensures horizontal movement of the mandrel with the wheel, sets the required cutting angle. In other words, the saw moves to a position where the front plane of the tooth fits tightly against the working surface of the wheel.

The marker marks the tooth from which sharpening begins.

The engine is turned on and the front plane is sharpened. inserting the tooth into contact with the wheel and moving the saw back and forth several times while pressing the tooth against the wheel. The thickness of the metal removed is regulated by the number of sharpening movements and the force of pressing the tooth on the abrasive wheel. After sharpening one tooth, the saw is removed from contact with the wheel, it turns on one tooth and the sharpening operation is repeated. And so on until the marker pen makes a full circle, showing that all the teeth are pointed.

The tooth sharpening is inclined on the front plane. The difference between sharpening a beveled tooth and sharpening a straight tooth is that the saw cannot be mounted horizontally, but at an angle. with an angle corresponding to the angle of inclination of the front plane.

The angle of the saw blade is set using the same pendulum goniometer. First the positive angle is set (in this case 8°).

After this, every second tooth is sharpened.

After half the teeth have been sharpened, the saw blade angle changes from 8° to 8°.

And every second tooth is sharpened again.

Back sharpening. To sharpen a tooth on the back plane, it is necessary that grinding machine saw blade made it possible to install the saw in such a way that the rear plane of the tooth was in the same plane as the working surface of the abrasive wheel.

If there is no machine for sharpening saw blades

Precisely maintain the required sharpening angles while holding the weight of the saw in your hands. The task is impossible even for a person with a unique eye and enviable stiffness of hands. The most reasonable thing in this case. for creating simple device for sharpening, which allows you to fix the saw in a certain position relative to the circle.

The simplest of these tools is a grinding stand, the surface of which is at the same level as the axis of the grinding wheel. By placing the saw blade on it, you can ensure that the front and back planes of the tooth are perpendicular to the saw blade. And if the upper surface of the stand is made mobile. fixing one side hinged and the other. Relying on a couple of bolts that can be screwed in and out. then it can be installed at any angle, making it possible to sharpen an inclined tooth on the front and rear planes.

True, in this case one of the main problems remains unresolved. Extracting the same front and back corners. This problem can be solved by fixing the center of the saw in relation to the abrasive wheel in the desired position. One way to implement this. Make a groove on the surface of the mandrel support on which the saw is mounted. By moving the frame with the wheel in the groove, it will be possible to maintain the required tooth cutting angle. But for sharpening circular saws different diameters or sharpening angle, it must be possible to either move the engine or the support, and with it the groove. Another way to ensure the desired sharpening angle is simpler and install stops on the step that lock the disc in the desired position. At the end of the article there is a video demonstrating this adaptation.

Sharpening quality control

GOST 9769-79 establishes certain tolerance values ​​for grinding parameters. The final impacts of the tips of the teeth should not exceed 0.2 mm (for saws with a diameter of up to 400 mm), radial. 0.15 mm. Runout is checked using a conventional indicator.

Circular saws are a tool that is used regularly in the woodworking and construction industries. A circular saw works with different materials, and the quality of the cut is great importance. Sooner or later the question of restoring saw teeth arises. The ability to carry out this work at a high level professional level will make it possible to use the cutting tool for a long time.

Necessity of the procedure

Circular saws are needed both in private households and in production. When building a house, creating furniture, cutting boards, timber - a similar tool is required everywhere. Properly sharpening a circular saw requires practical skill and knowledge.

Circular saws compare favorably with others cutting tool:

• chain;
• saber;
• longitudinal.

Disc circular devices have significant productivity, and their service life is also much longer. Sharpening circular saws is important necessary stage, without it the tool will not work fully. Thanks to various attachments with carbide tips, as well as pobedit coatings, cutting can be carried out with both wood and metals.

To sharpen discs with different attachments, special equipment is required. If the disk is treated “scientifically”, this will greatly extend its service life.

Timely sharpening of circular saws is carried out when there are several obvious signs.

• The engine begins to experience unnecessary loads. The reason is simple - the teeth are dull and additional resources are required to process the material. There is a danger: if the disk is damaged, if there is no engine shutdown relay, the machine may fail.
• If chips and chips form on the cut, and the cut itself becomes too wide, then this is a sure sign that the tool should be repaired.
• A foreign smell of burnt material appears, and dark spots are visible on the cut line.
• The time required to process a part increases.

Types of saws

If the disk is properly sharpened and the teeth are set according to the pattern, then it can process the workpiece in any direction relative to the wood fibers.

There are these types of tools:

• saw with carbide blades;
• discs made of solid metal;
• discs with teeth treated with hard material;
• discs with heavy-duty soldered teeth.

Hardwoods are processed with discs that have special grooves. Technological breaks prevent tool deformation and prevent it from overheating during the production cycle. Vibration and background noise are also significantly reduced, and the quality of the line formed by the cut is improved. The saw has teeth that are machined at a certain angle, each tooth has several cutting edges.

There is a main edge, additional ones are mated to it, and intersecting planes are formed:

The planes themselves also vary in different mates.

To use saws correctly and productively, you must consider the material you are working with.

The teeth can be straight, they are usually used for preliminary cutting of material. These teeth provide a low level cut. However, the productivity of such teeth is quite high.

Beveled teeth provide a more precise line and are suitable for cutting materials such as:

• plywood;
• PVC sheets;

The teeth ensure an even cut without the material crumbling.

There are also discs that have a bevel at the leading edge of the cutter, and also have a bevel at the trailing edge. Options for alternating different teeth with different bevels are possible. Such tricks ensure a clean cut, but you should remember: the denser the material, the faster such teeth become dull.

Trapezoid tooth– this tooth configuration ensures a long service life for the tool. Often a complex design is used, when trapezoidal and straight teeth alternate. The latter make the primary cut, which allows straight-shaped teeth to “polish” the cut.

Typically, such a tool is used in cutting laminate flooring, as well as PVC sheets.

Cone shaped tooth– such teeth are auxiliary and are designed to work with materials that have a laminated surface. They ensure correct cutting without the formation of any chips.

Teeth of this configuration are practically not used independently.

Sickle shaped tooth– in this case, the teeth are bent, which makes it possible to accurately cut the material across the wood fibers.

Determining the degree of wear and sharpening angle

Circular saws, sooner or later, lose their performance characteristics during operation; it is possible to effectively extend the service life of the tool if it is sharpened again correctly. This operation is simple; in many cases you can do the work yourself.

First of all, you should have an idea: what parameters the working disk of the unit has. The second most important parameter is the sharpening angle, what parameters the tooth itself has.

Before you start working, you should test the tool to understand how relevant its restoration is. The disc should be inspected by removing it from the machine. An important indicator is the change in size, this can be seen even with a cursory examination.

Discs that have been treated require a special approach special materials. The tipped disc allows you to significantly increase the service life of the cutting tool. It can work with any type of tree, even material of increased hardness.

The “knobs” themselves are made of heavy-duty steel of the following grade:

• 50 HVA;

Some other grades of steel are also used.

To begin work, it is advisable to have the required template, according to which you can adjust the geometry of the cutting surface. Usually the template is made of tin or cardboard.

The teeth themselves have a standard prescribed in GOST 9768-78, however, each manufacturer has differentiation in inclination angles and shapes.

In the absence of a template, you will need to determine the parameters of the teeth yourself. There is a tool for this - a pendulum protractor. With this tool you can accurately set the sharpening angle.

Another option is take a new disk and use it as a template. You should take a sheet of thick cardboard and draw precise outlines on it with a pencil. Then, using a pendulum angle gauge, the exact configuration of the soldering should be established. This It is recommended to save the sample so you can work with it in the future, using as a reference.

After finishing the work, it will be necessary to test the resulting sample by comparing it with the standard. The angle of inclination in such saws ranges from 15 to 25 degrees.

If the model is transverse, then the differentiation can be from 5 to 10 degrees. If the model is universal, then the tilt angle is only 15 degrees.

Please note when starting work: the rake angle may have negative meaning. Similar models are used to work with PVC sheets, as well as with soft metals.

Methods

You can sharpen the instrument yourself (if it does not have a pobedit coating) at home. And also in such cases, you can use a simple machine on which you can successfully sharpen any edges. It is very important to choose the right circle.

They come in the following types:

• corundum;
• diamond

It is best to use a unit in which the disc can be positioned at different angles.

There are rules:

• the main defect occurs on the edge from above, that is, the edges are rounded within 0.11-0.31 mm - this is the starting point from which sharpening should begin;
• Both the front and rear parts should be processed, this should be done at least 26 times;
• size does not exceed 0.051-0.151 mm;
• front and back edges are processed identically;
• After the end of the cycle, the finishing process should be carried out, that is, clean the surface with “zero” sandpaper.

The work of creating a new configuration requires compliance with regulations and has its own complexity.

• Familiarize yourself with the requirements, in particular, clarify the number of revolutions. It is clear that for metal this figure will be noticeably lower. Wooden elements are being processed a large number rpm
• The material from which the soldering is made can withstand heavy loads, its service life is significant, but even it sooner or later receives defects, chips and cracks appear.
• A sure sign that the material is beginning to “tire” is the appearance of microburrs and roughness on the surface. Defects will appear in these places after some time.

To carry out sharpening correctly, you should know what types of teeth there are:

• straight;
• tooth with a bevel on the back;
• trapezoidal;
• cone-shaped;
• concave.

How to sharpen:

• The disc should be thoroughly cleaned using alcohol or chemicals;
• all working planes are processed;
• it is permissible to remove metal 0.051-0.151 millimeters;
• sharpen perhaps no more than twenty-five times;
• you can sharpen using a special file, if you have practical experience;
• It is recommended to sharpen carbide teeth using separate equipment;
• Victory tips can only be “taken” using a special machine that contains a diamond wheel.

Markers should be made to mark the starting point. The teeth are arranged in such a way that they are in a single plane. After completing the sharpening cycle, each tooth is tested and processed separately.

There are several types of tooth alignment.

• Wavy, each tooth is straightened at a certain angle of inclination, thus creating a semblance of a wave.
• Protective, two teeth have angles of inclination, the third tooth is present without inclination. This method is effective even when working with mahogany and oak.
• Classic, when the teeth are variable - angles of inclination to the left and right.
• Frontal.
• Rear.
• A tilt is made at the frontal plane.
• A tilt is made at the rear plane.

There is another parameter - the sharpening angle, but it usually “works” as an additional tool.

For manual sharpening you will need:

• wooden blocks (2 pieces, size 52x32 mm);
• drill, screwdriver;
• screwdriver bit;
• a hacksaw for processing ceramics;
• marker;
• ruler;
• screws or self-tapping screws.

The middle of the bars is cut out, they are fixed on a solid plane using self-tapping screws. A mark is made on the bars so that a crown for processing ceramics is then placed in the sawn markings, which, in turn, is attached to a screwdriver.

The surface of the stand coincides with the surface of the disc. The circle lies on a stand, the sharpening plane should be at an angle of 90 degrees to the saw blade. This simple device is equipped with a swivel unit. This reliable fastening Allows uniform processing of all tool teeth. Using a marker, you make markings, which makes it possible to correctly determine the angle of inclination.

Machine tools

All equipment that provides sharpening has one operating principle. The only differences are in the performance of the equipment.

Household units can work for half an hour, then they should be disconnected from the network for a while. A professional tool is able to function almost without stopping for the entire shift (8-10 hours).

The tool kit includes an abrasive wheel and grinding material.

Using machines to sharpen teeth provides a number of advantages:

• the ability to adhere to a given angle;
• increases the efficiency of production operations and their speed;
• It is possible to use a variety of disks.

Using the machine you can even work with hard alloy coatings. The grit of the grinding wheel varies. As an example, if the diameter is 126 mm, then the speed can be 2300 rpm.

The rotation speed of the disk can deviate within 510-720 rpm, it all depends on what fragility factor the disk has.

The harder the material, the greater the speed required to process it.

The functionality of the installation determines whether the workpiece or the spindle will move. Movement of the entire device is also possible.

The angle of inclination can be measured using a pendulum inclinometer; some units have a built-in scale to determine the angle of inclination of the teeth.

The teeth are usually sharpened first from the front, then from the rear.

To sharpen pobedite-tipped teeth, a diamond wheel is required. Discs that have soldering must be sharpened using special attachments or a diamond wheel coated with diamond.

The units have the following parameters:

• thickness from 15 to 42 mm;
• outer diameter 11-252 mm;
• hole for fastening (16, 20, 33 mm).

A lot depends on the performance characteristics of the abrasive, they should be emphasized Special attention.

Standard cutters are not always suitable for the job, so tools with special heavy-duty soldering (corundum, diamond coating) are available.

And finally, some advice from experts:

• the frontal part should be monitored more closely;
• when working with massive elements, the side planes are subject to heavy loads;
• radius rounding no more than 0.21 mm;
• It’s best to process the teeth both front and back;
• metal removal parameters should not exceed 0.151 mm;
• the disk is cleaned before starting work, all relevant corners should also be checked;
• sharpening the teeth at the desired angle requires practical experience; in the absence of this, it is better to take the disc to a workshop;

• wheels with diamond coating should be cooled using a special coolant;
• unit designed for sharpening circular knives, capable of working with a workpiece in only one plane;
• the teeth should not be allowed to wear to a rounding of more than 0.21 mm, otherwise it will be difficult to do normal sharpening;

A disk tool for cutting wood is always useful during construction. A circular saw is convenient because it allows you to quickly cut material when minimum costs energy and time. As for the quality of the cut, we can say that it is ideal, but only when the saw is in good working order and well sharpened. Otherwise, working with such a tool is even dangerous, so you should sharpen the circular saw.

It is not difficult to determine the need for sharpening: a blunt tool cuts the workpiece poorly, which is immediately noticeable. There are two options here: either take the blade to a workshop, which is not always profitable in terms of time and money, or sharpen the circular saw with your own hands. This may seem difficult at first glance. But if you delve into the essence of the saw in more detail, it will not be difficult to service the tool at home.

There are very definite signs by which one can judge the condition of the instrument. Saw sharpening is necessary when the following clearly appears:

1. During operation, smoke appears, a specific smell of burnt wood, the casing covering the saw teeth begins to heat up quickly.
2. When moving the tool along the workpiece, you need to apply significant effort, as if pushing the saw forward.
3. After cutting the material and visually inspecting the sawn edge, black deposits or many chips, fiber burrs, and chipped areas are visible.
4. When you carefully examine the saw teeth through a magnifying glass, you can see that the cutting parts have rounded edges rather than sharp ones.

All this requires immediate cessation of work, otherwise there is a high risk of damage to the material and wear of the circular saw to a state where sharpening will no longer help it.

Basic sharpening angles for circular saws

The tooth of a circular saw, which is usually made of carbide metal, has a complex structure. It has three cutting edges as standard, so you need to sharpen the teeth in such a way as to sharpen these edges. But the main thing when sharpening is to observe the angles at which the tooth planes diverge from the edges, and the angles of attack between the tooth plane and the workpiece. The last point is important to maintain the characteristics of the saw blade.

The front edge, the one that first cuts into the workpiece as the saw moves, forms the main cutting edge with the rear edge. The angle at which the rake edge meets the material is called the rake angle Y (angle of attack). The angle between the back edge and the front edge is the sharpening angle. If you subtract the rake angle and the point angle from 90 degrees, you get the back angle.

In practice, it is important to maintain these angles for each type of blade when sharpening. It is according to the front angle that saws are divided into types:

1. Longitudinal cutting, where the rake angle should not go beyond 15–25 degrees.
2. Transverse cutting, where it is permissible to sharpen the front edge of the tooth at an angle of 5–10 degrees.
3. Universal discs that can handle both longitudinal and transverse cuts quite easily; their rake angle should be maintained around 15 degrees.

The bevel angle of the rear and front planes is also important: the sharper it is, the easier it is for the saw to enter the material, but wear occurs faster.

Follow the rules! When sawing hardwood, saws must be sharpened so that the point angle and bevel angle are as small as possible (within acceptable limits). This increases the service life of the disc until the next sharpening.

Types of circular saw tooth settings

Before sharpening the circular saw, you need to check whether the teeth are set. To do this, measure the width of the tooth with a caliper, and then make a small cut in a piece of hardwood and measure its width. If the circulation disc is set apart, then the cut should be wider than the tooth. Otherwise, the saw teeth must be set apart before sharpening operations.

The complexity of the setting process is due to the need to move the teeth to the side at the same distance. This can be achieved by using a factory-made device for wiring circular saws. Each tooth should be started from the middle of its size. For different densities wood materials The degree of teeth set must be different, but without going into details, we can say that the teeth are set wider for sawing soft rocks than for hard ones.

There are three main wiring methods:

1. Stripping type wiring. This method boils down to the fact that after two teeth the tooth remains in its place without change, the rest are deflected in different sides. This saw preparation is good for working with solid wood.
2. Option classic wiring, when the saw teeth alternately move to the right and then to the left. This universal method can be used for almost all types of saws.
3. The so-called wavy layout, distinctive feature which is the retraction of the teeth not to a strictly defined distance from the center, but to different distances with a deviation within 0.3–0.7 millimeters.

General rules for sharpening a circular saw

To sharpen the disks for a circular saw, you need to prevent them from wearing out too much, namely, the radius of rounding of the cutter should not be more than 0.2 mm. The following basic rules are followed:

1. The main edges are processed first, of which the front faces wear out the most.
2. In extreme cases, if the side edges are heavily worn, they are corrected.
3. No more than 0.15 millimeters of the thickness of the saw metal is removed at a time.
4. When finishing the edges electric tool Overheating of the metal is not allowed, in which case its properties will deteriorate.
5. To ensure the maximum service life of the saw, when it can be sharpened up to 30 times, you should sharpen both edges: the front and back, removing the same amount of metal.
6. Sharpening circular saws with tools not intended for this purpose, such as a grinder and a metal cutting disc, is not allowed.

After the basic sharpening operations, you can refine the teeth with fine sandpaper. The quality of tool sharpening is checked under working conditions. If everything is in order, the cutting of the material will be clean, smooth, without visible defects or blackening.

How can you sharpen a circular saw?

Sharpening discs is impossible without the use of a special tool. For these purposes you can use:

1. Special wheels for sharpening saws, made on the basis of diamond abrasives.
2. A regular file for sharpening a saw, but you also need to have a vice to secure the saw and wooden block, used as a guide.
3. Processing for professional equipment- the fastest and highest quality method of sharpening, but requiring large material costs to purchase the tool.

Do-it-yourself saw sharpening at home

Attention! To sharpen circular saws with your own hands, it is advisable to have certain skills in sharpening tools. If you don’t have any, at least practice on sandpaper, sharpening a regular knife.

When working with a disk, the main thing is not to damage the cutting surface, and this can easily happen if the hand trembles and the feed angle is disrupted. To avoid negative consequences You should study sharpening methods, and then everything will work out correctly. Distinguish manual method restoration of the cutting elements of a circular saw and a method using sharpening equipment.

Manual method

You can sharpen the teeth yourself by hand using a file to achieve high quality results if they do not have a bevel, that is, the surface of the front edge is perpendicular to the surface of the blade. The process looks like this:

1. From dense wood prepare a block with a cross section of about 50x50 mm and a length of 100 mm. The sides of the bar must be strictly perpendicular to each other.
2. Mark with a marker any tooth that will be reported and the first to be processed.
3. The saw blade is clamped in a vice together with the beam so that the front edge of the element being processed is flush and in the same plane with the surface of the beam (the beam in this case acts as a guide for the file).
4. A thin file (its thickness should allow it to fit freely into the cavity between adjacent teeth) is applied to the surface of the tooth being processed and at the same time to the block and sharpening is carried out using methodical movements back and forth.
5. In this way, each tooth is gradually sharpened, monitoring the condition of the timber and, when working out its surface, slightly shifting the plane.

Use of machines

Using a special machine, circular saws are sharpened very easily and quickly. The main thing is that there is no need to monitor the angle of the disk feed. Once it has been set, the operator only has to move the teeth into the processing area and lightly press the tooth plane against the rotating diamond disk.

This equipment can be used to sharpen carbide-tipped circular saws and conventional circular saws. The simplest machine for sharpening operations of circular saws has the following structural elements:

1. An electric drive with a grinding disc fastening system is a stationary part of the equipment.
2. The stand, which moves along the guides, is responsible for feeding the saw blade into the processing area.
3. A saw blade clamp on a stand, which is designed to hold the blade in a constant position when it is fed to the sharpening disk.

Pay special attention! Discs with different types teeth require an individual approach to sharpening. When the front edge is beveled, it is fed into the processing area at an angle to the horizontal, for which one edge of the stand is raised accordingly.

If you have additional questions on the topic of sharpening saws or you have your own experience in carrying out such operations, respond in the comments! Your comments are important to us!

Circular or circular saw - indispensable assistant V household and in production when cutting wood materials. It is more efficient than other types of saws, such as chain saws, reciprocating saws, and rip saws. To get the perfect cutting of workpieces, you need to monitor the sharpening of circular saws with carbide tips.

Circulating saws - what are they?

Saw blade at correct sharpening and setting the teeth, it is able to qualitatively and accurately cut the workpiece in any cutting direction relative to the fibers.

There are several types of cutting blades for a circular saw:

• Discs with a base and cutting area made of solid metal;
• Discs with a solid metal base and coating of hard structure materials on the teeth;
• Metal blades with carbide tipped.

High-quality cutting of workpieces is impossible when the teeth are worn out or dull. An accompanying phenomenon of working with a blunt tool will be excessive load on the engine, the risk of jamming, and unsafe cutting operations. Circular saws need to be sharpened.

For cutting hardwood, it is permissible to use only discs that have special grooves. Technological breaks in the blade prevent general deformation of the tool during possible heating during operation. This eliminates the appearance of a vibration background and deterioration of the cut line.

Geometry of cutting elements

The working element of the saw - the tooth - has a certain geometric shape with the presence of not one, but several cutting edges. There is always one main edge and additional ones formed by the intersection of planes “A”, “B” and “C” in certain combinations. To work with different materials It makes sense to select discs with the most suitable shape of cutting teeth.

Straight tooth

Saw blade with such working area Designed for rough cutting of lumber. The cut is rough, of low quality, and the operations are carried out relatively quickly.

Types of circular saw teeth

Beveled tooth

The front plane of the cutting edge, made in this form, ensures cuts with an accurate and even line. The saw is ideal for working with composite type materials: plywood, chipboard (with single-sided and double-sided lamination). After cutting blanks of solid lumber, it is chipped, practically no chips are observed.

There are discs with a beveled leading edge of the cutter, some with a beveled trailing edge, or a variant with alternating teeth (variably beveled blade). When working with a tool with a beveled surface of the trailing edge of the cutting element when cutting hard wood, a clear, high-quality cut is observed, but the saw quickly becomes dull.

Trapezoidal tooth

The main advantage of such a saw is the slow wear of the disc due to the absence of the need for frequent sharpening. sharpening machine. Typically, the entire blade line consists of alternating cutting elements - straight and trapezoidal teeth, working in tandem. The taller trapezoid tooth roughs the cut, allowing the main straight edge to cut more easily. The tool can be used for cutting plastics and hard laminates.

Circular saw blade - characteristics

Conical tooth

An auxiliary type of tool designed for cutting materials with a laminated surface prior to the main cut. The operation is carried out to avoid the appearance of chips on the front part of the product. This saw blade is not used as an independent working unit.

Crescent tooth

Blades with a concave tooth shape are convenient for cutting material in the transverse cutting direction relative to the location of the fibers.

Determining the degree of wear of the circulation disc

Obtaining a high-quality result when working with a circular saw is only possible if you sharpen circular saws in a timely manner. Otherwise, damage to the workpieces, rapid wear of the saw drive mechanisms, and an increase in injuries at work may occur. To avoid this, it is necessary to clearly monitor the wear of the cutting blade, focusing on the following signs:

• The movement of the workpiece on the work table during cutting occurs with the use of great physical force;
• Cracks and chips are observed along the cut line;
• During operation, the engine overheats;
• There is a burning smell in the air;
• The material burns, which appears as dark areas along the cut line.

If any of these signs are detected, you must immediately begin sharpening your circular saws yourself. Also, before carrying out work, you can check the sharpness of the saw, focusing on tactile sensations or visually using magnifying glass. Allowable rounding radius cutting angle should correspond to a value of 0.1-0.2 mm. When cutting large workpieces, all working edges wear out.

How to sharpen a saw blade - rules

• Only the pobedit disk, cleaned of dust and dirt, is subjected to sharpening;
• The disc is cleaned using detergents, without the use of mechanical processing;
• All working surfaces are sharpened;
• The permissible thickness of metal removal is in the range of 0.05-0.15 millimeters;
• The permissible number of sharpening operations is no more than 25 times;
• Saws are sharpened manually with a file or on machines.

Sharpening saw blades with carbide teeth

Pobedite soldering tips are sharpened using a special machine or a homemade device for grinding wheel. The device is a clamp in which the disc is clamped, maintaining certain sharpening angles relative to the emery. A diamond wheel is considered the best for sharpening a pobedit.

A marker marks any point as a reference point. Place the main work surface teeth to the grindstone so that they are in the same plane. Grind each tooth in turn until the entire circle is completed. Rearrange the disk with the auxiliary plane to the grinding wheel. They grind a different plane for each tooth. This is how the carbide-tipped discs are completely sharpened step by step.