How To Sharpen A Circular Saw At Home
If there is no saw blade sharpener
Maintain the required sharpening angles precisely while holding the saw in your hands. The task is unbearable even for a person with a unique eye and enviable firmness of hands. The most reasonable thing in this case. Make the simplest sharpening device that makes it possible to fix the saw in a certain position in relation to the circle.
The simplest of such devices for sharpening circular saws is a stand, the surface of which is flush with 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 movable. By hinging one side and the other. Supported by a pair of bolts that can turn in and out. Then it can be installed at any inclination, getting the opportunity to sharpen an oblique tooth along the front and rear planes.
True, in this case, one of the main problems remains unresolved. Exposure of the same front and rear sharpening angles. You can solve this problem by fixing the center of the saw relative to the abrasive wheel in the desired position. One way to implement this. Make a groove on the surface of the stand for the mandrel on which the saw is installed. Moving the mandrel with a circle along the groove, it will be possible to maintain the required rake angle of the tooth sharpening. But for sharpening circular saws with different diameters or sharpening angles, it must be possible to either move the motor or the stand and the groove with it. Another way to provide the required sharpening angle is simpler, and consists in installing the stops on the table to fix the disc in the desired position. At the end of the article there is a demonstration of such a device.
Material and properties of carbide teeth
In domestic saws, sintered tungsten-cobalt alloys of grades VK (VK6, VK15, etc.) are used as material for cutting inserts. The number means the percentage of cobalt). BK6 has a hardness of 88.5 HRA, BK15. 86 HRA. Foreign manufacturers use their own alloys. Hard alloys VK consist mainly of cobalt-cemented tungsten carbide. The characteristics of the 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.
Attach the carbide plates to the disc by high-temperature brazing. As a material for soldering, at best, silver solders are used (PSr-40, PSr-45), at worst. Copper-zinc solders (L-63, MNMTS-68-4-2).
Carbide tooth geometry
The following types of teeth are distinguished by shape.
Straight tooth. Typically used in rip saws where quality is not critical.
Oblique (beveled) tooth with left and right angles of inclination of the posterior plane. Teeth with different angles of inclination alternate with each other, which is why they are called alternately cut. This is the most common tooth shape. Depending on the size of the sharpening angles, saws with alternating teeth are used for sawing a wide variety of materials (wood, chipboard, plastics). Both in the longitudinal and transverse directions. Saws with a large flank angle are used as scoring saws when cutting double-sided lamination boards. Their use allows you to avoid coating chips at the edges of the cut. Increasing the bevel angle reduces the cutting force and reduces the risk of chipping, but at the same time reduces the tool life and strength of the tooth.
Teeth can be inclined not only back, but also front plane.
Trapezoidal tooth. A feature of these teeth is the relatively slow speed of blunting of the cutting edges in comparison with alternating bevel teeth. They are usually used in combination with a straight tooth.
Alternating with the latter and slightly rising above it, the trapezoidal tooth performs the rough sawing, and the straight one following it. Fine. Saws with alternating straight and trapezoidal teeth are used for cutting boards with double-sided lamination (chipboard, MDF, etc.), as well as for sawing plastics.
Conical tooth. Tapered saws are auxiliary and are used to cut the lower layer of the laminate, preventing it from chipping when passing the main saw.
In the vast majority of cases, the front face of the teeth is flat, but there are saws with a concave front face. They are used for fine cross-cutting.
Sharpening circular saws
Sharpening angles of teeth
The sharpening angles are determined by the purpose of the saw. THOSE. The one for which material cutting and in which direction it is intended. Rip saws have a relatively large rake angle (15 °.25 °). For cross-cut saws, the γ angle usually ranges from 5-10 °. Versatile cross and rip saws have an average rake angle. Typically 15 °.
The sharpening angles are determined not only by the direction of the cut, but also by the hardness of the material being cut. The higher the hardness, the smaller the front and back angles should be (less sharpening of the tooth).
The rake 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
When cutting massive workpieces, side edges are also subject to rapid wear.
Do not dull the saw too much. The radius of rounding of the cutting edge should not exceed 0.1-0.2 mm. In addition to the fact that when working with a very blunt saw, productivity drops sharply, sharpening it takes several times longer than sharpening a saw with a normal bluntness. The degree of bluntness can be determined both by the teeth themselves and by the type of cut they leave.
Correct sharpening of circular saws consists in ensuring the maximum number of sharpenings, which in the optimal case can reach 25-30 times, while ensuring the proper sharpness of the cutting edge. For this purpose, it is recommended to sharpen the carbide tooth on the front and back planes. In fact, the teeth can be sharpened along one front plane, but the number of possible sharpenings is almost two times less than when sharpening along two planes. The figure below illustrates why this is happening.
The last pass when sharpening saw blades is recommended to be done along the back plane of the tooth. Standard metal removal rate. 0.05-0.15mm.
Before sharpening, the saw must be free of dirt such as resin and the values of the sharpening angles must be checked. On some saws they are written on the disc.
Equipment and materials for sharpening saw blades
When using abrasive wheels (especially diamond), it is desirable to cool them with coolant.
With increasing temperature, the microhardness of abrasive materials decreases. An increase in temperature to 1000 ° C reduces the microhardness by almost 2-2.5 times compared to the microhardness at room temperature. An increase in temperature to 1300 ° C causes a decrease in the hardness of abrasive materials by almost 4-6 times.
The use of water for cooling can lead to rust on the parts and assemblies of the machine. To eliminate corrosion, soap and certain electrolytes (sodium carbonate, soda ash, trisodium phosphate, sodium nitrite, sodium silicate, etc.) are added to the water, which form protective films. For normal sanding, soap and soda solutions are most often used, and for fine sanding. Low concentration emulsions.
However, when sharpening saw blades at home with a low intensity of sharpening work, they do not resort to cooling the wheel so often. Not wanting to waste time on it.
To increase the productivity of sharpening with abrasive wheels and reduce specific wear, you should choose the largest grain size, which ensures the required surface cleanliness of the sharpened tooth.
To select the grain size of the abrasive, in accordance with the sharpening stage, you can use the table in the article about the sharpening bars. For example, in the case of using diamond wheels, wheels with a grain size of 160/125 or 125/100 for finishing can be used for rough sharpening. 63/50 or 50/40. Wheels with grit sizes 40/28 to 14/10 are used for chipping.
The peripheral speed of the wheel when sharpening carbide teeth should be about 10-18 m / s. This means that when using a circle with a diameter of 125 mm, the rotation speed of the engine should be around 1500-2700 rpm. Sharpening of more brittle alloys is carried out at a lower speed from this range. When sharpening carbide tools, the use of hard modes leads to the formation of increased stresses and cracks, and sometimes to chipping of the cutting edges, while the wear of the wheel increases.
When using machines for sharpening circular saws, changing the relative position of the saw and the grinding wheel can be realized in different ways. Moving one saw (the wheel motor is stationary), the saw and the motor move at the same time, only the wheel motor is moving (the saw blade is stationary).
A large number of sharpening machines of various functionality are produced. The most complex and expensive programmable complexes are capable of providing a fully automatic sharpening 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 per tooth), feeding for grinding (bringing it into contact with the wheel) and controlling the thickness of the metal removed from the tooth. Produced by a worker manually. It is advisable to use such simple models at home, when the sharpening of circular saws is episodic.
An example of the simplest machine for sharpening circular saws is the system, the photo of which is shown in the photo below. It consists of two main units. A motor with a disc (1) and a support (2) on which the saw to be sharpened is mounted. The turning mechanism (3) is used to change the angle of inclination of the blade (when sharpening teeth with a beveled front plane). The screw (4) moves the saw along the axis of the abrasive wheel. This ensures the setting of the required rake angle. The screw (5) is used to set in the desired position of the limiter, which prevents excessive entry of the disc into the interdental cavity.
Saw blade sharpening process
The saw is installed on a mandrel, clamped using a tapered (centering) sleeve and nut, then set in a strictly horizontal position using the mechanism (3). This provides a bevel angle of the front plane (ε1) equal to 0 °. For machines for sharpening discs 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 the horizontal position of the machine.
By turning the screw (4) of the mechanism providing horizontal movement of the mandrel with the circle, the required rake angle is set. In other words, the saw moves to a position in which the front plane of the tooth fits snugly against the working surface of the wheel.
A marker is made to mark the tooth from which sharpening begins.
The engine is turned on and the front plane is sharpened. By bringing the tooth into contact with the circle and several back and forth movements of the saw, while simultaneously pressing the tooth against the circle. The thickness of the removed metal is regulated by the number of grinding movements and the force of pressing the tooth against the abrasive wheel. After sharpening one tooth, the saw is removed from contact with the wheel, rotated by one tooth and the sharpening operation is repeated. And so on until the marker mark makes a full circle, indicating that all the teeth are sharpened.
Sharpening of a beveled tooth. The difference between sharpening a beveled tooth and sharpening a straight tooth is that the saw must be installed not horizontally, but with an inclination. With an angle corresponding to the bevel angle of the front plane.
The tilt angle of the saw is set using the same pendulum goniometer. First, a positive angle is set (in this case 8 °).
After that, every second tooth is sharpened.
After sharpening half of the teeth, the tilt angle of the saw blade changes from 8 ° to 8 °.
And every second tooth is sharpened again.
Rear sharpening. To sharpen a tooth along the back plane, it is necessary that the saw blade sharpener allows you to set the saw in such a way that the back plane of the tooth will be in the same plane with the working surface of the abrasive wheel.
Deviations of sharpening angles should not exceed:
- For the front corner. ± 1 ° 30 ‘;
- For clearance and bevel angles of the front and rear planes. ± 2 °;
Sharpening circular saws
Circular saws are used throughout the construction industry. Many works require resizing the building materials used, making cuts and much more. The circular saw allows you to quickly cut a wide variety of materials, while the cutting speed is very high, and the quality of the cut made is the best. The constant use of the equipment in question determines that the cutting tool begins to become dull, this has a significant impact on the efficiency of the work carried out and their quality. That is why many people think about how to sharpen circular saws with their own hands. After all, the ability to perform such work with high quality will significantly save.
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Required tools
With your own hands, discs for a circular plate can only be sharpened with special tools. There is also a machine that allows you to automate the process, make it more efficient.
To carry out work on sharpening a disc with your own hands, you can use the following tools:
- Mounting vise;
- File;
- Wood block.
A circular saw sharpener can also be used, which does not require the above tools.
Principles and angles of sharpening circular saws
The saw has four main corners of the saw blade sharpening along the working part. The angles in question, like the shape of the tooth itself, can be called the main operational characteristics. Each tooth can be characterized as follows:
- Front and back angle;
- Cut angles of the front and back surfaces.
The values of the above parameters depend on the purpose of the sawing device, the type of workpiece material.
Circular saw tooth surfaces
According to the above parameters, several saws can be distinguished:
- For slitting. In this case, the rake angle should be between 15 ° and 25 °.
- When performing cross-cutting, the indicator in question should be from 5 ° to 10 °.
- The universal version is recommended to be sharpened at an angle of 15 °.
With prolonged use of a carbide saw, significant wear occurs at the topmost cutting edge. When considering the plane of the tooth, it is worth noting that more wear is on the front surface.
Types of circular saw teeth
Sharpening circular saws at home
You can sharpen the saw with your own hands without using a special sharpening machine, which has a high cost and is rarely used for its intended purpose due to the use of carbide material when creating a cutting edge. However, you cannot just hold the circle in your hands, since you need to achieve certain cut parameters to ensure the required performance indicator.
To fix the toothed wheel in a strictly specified position, an ordinary flat stand is used. It has the following features:
- The surface of the flat stand must be level with the axis of the grinding wheel.
- Place the gear wheel on a stand so that the sharpening plane is perpendicular to the saw blade.
- The device in question for teeth located at a certain angle is equipped with a swivel joint.
The considered device allows you to fix the workpiece in relation to the used abrasive material. With the help of a colored marker, marking lines are drawn, which allow you to select the correct angle. A vice is also needed, in which the created fixation device is attached.
When to carry out work on the restoration of circular saws?
Quite an important question can be called determining when the sharpening of circular saws should be carried out. Heavy wear and tear can lead to the inability to carry out such work. Three clear signals can be distinguished that determine the need for sharpening the circular saw blade:
- The appearance of smoke, heating of the protective casing. The tool usually has a special protective cover that can get hot if the disc is dull. It should also be noted that in special cases, smoke appears due to strong heating of the cutting zone.
- Also, with a mechanical feed, when the pressure is adjusted by hand, great effort should be made to obtain the desired result.
- When processing wood or other material, traces of carbon deposits and a corresponding odor appear in the cutting area.
In the above situations, it is recommended to sharpen the circular saw blade.
Sharpening with a machine
If it is possible to purchase a special machine, then the process in question can be carried out with the maximum efficiency indicator. Such a device is compact in size, it can be used at home.
Particular attention is paid to the selection of the abrasive wheel. In this case, we note the following nuances:
- Carbide wheel is difficult to sharpen.
- When choosing, you should pay attention to circles from elbor, with diamond grit or from green silicon carbide.
The sharpening process using professional equipment is very simple. The disc is mounted using a special retainer. It was created taking into account the design features of the circle. We will pay special attention to the fact that when using special machines it is very easy to sharpen circular saws while maintaining the required parameters. In this case, the error is minimal. This is due to the fact that the design has a special angle indicator. In order not to be mistaken at the time of work with which teeth have already been processed, you should mark the starting point using a marker.
Sharpening the circular saw. How to sharpen a disc
Circular saw. a tool with many (teeth) for cutting (sawing) hard materials (wood, plastic). A circular saw is performed in the form of a metal plate, on the working edge of which there are teeth. It makes it possible to make inclined, rip and cross cuts.
A circular (circular) saw is a reliable and irreplaceable tool, which is indispensable when building a country house or summer cottage. It surpasses other types of saws in terms of cut cleanliness and accuracy, especially if it is necessary to cut along boards or beams. The service life of a circular saw is not least determined by the quality of its sharpening.
You will need. File, vise, wooden block
1) Correct and timely sharpening is especially important for low-power circular saws. Blunt disc increases the load on the electric motor, which overheats and can fail.
2) There are signs of wear on the saw, which is a signal that it needs to be sharpened:
4) When sharpening in the machine, unplug the power cord (to avoid accidental starting of the unit). Grip the blade by placing thin pieces of wood on both sides and pressing them against the saw teeth.
5) Use a marker to mark the tooth to start sharpening. When sharpening the first tooth, remember the number of movements with a file, since the remaining teeth should be sharpened with the same force and with the same number of movements.
6) If you chose to remove the disc from the machine, clamp it in a vice with wooden dies and follow the procedures described above exactly. Rotate the blade in a vise as you sharpen the teeth.
7) When all the teeth have been sharpened, insert the disc into the machine, plug it in and cut an unnecessary piece of wood. If there is a lot of noise or uneven material feeding, check if the saw teeth are the same height. To do this, bring the marker to the cutting edge, and then turn the blade a full turn in the direction opposite to the direction of rotation. Examine the disc. A mark will remain on each tooth, which allows you to identify teeth that differ from others in height. Use a file to carefully reduce the height of the long teeth.
8) Higher quality sharpening is achieved on special sharpening machines, which may not always be available to the home master.
There are several power tools in construction and repair, which you probably cannot do without. At the very least, they significantly increase labor productivity, save time and help to do a certain part of the work at a higher quality level. The necessary tools include an angle grinder, hammer drill, screwdriver and, of course, a circular saw.
When you need to quickly and evenly cut material (wood, plastic, metal and even stone), a circular saw always comes to the rescue in the work. It is easy to work with this tool even in the absence of great experience in the past, and modern technologies have made it possible to manufacture circular saws with high technical characteristics and a set of very convenient functions. Interested in how to sharpen a circular saw correctly at home? A circular saw, like any other tool, requires compliance with all operating rules and, of course, careful care. The main problem that a person faces after using a circular saw for a while. This is her wear. Even when buying quality tools from the world’s leading manufacturers, sooner or later you will have to sharpen the saw yourself. But this is not as difficult as it might seem at first glance, and we will tell you how to sharpen a circular saw quickly and without unnecessary problems.
How to sharpen a circular saw: a few basic rules. The answer to the question “how to sharpen a circular saw?” depends on what tools you have. The fastest way to get the tool into working order is to use a special grinder, but few people have the opportunity to purchase such a machine for the home. It is very easy to determine that a circular saw needs to be sharpened immediately.
Surely, you will immediately notice how difficult it has become to carry out normal work with a saw. You have to put in more effort, perhaps even more alarming “symptoms” appear: unpleasant odor, smoke, dark saw marks on the material. Saw blade sharpening starts from the rear.
Usually, sharpening is carried out on a machine, first removing the cord from the outlet to avoid accidents. Next, you need to mark the tooth from which sharpening begins and exactly remember the number of movements with a file.
The rest of the teeth are sharpened as well, making the same effort. Then turn on the machine and try to cut any material. Ideally, the saw should run without a lot of noise. If there are difficulties in work, you should examine the disc and identify the tooth that is different from the rest. Adjust the tooth height with a file.
How to sharpen saw blades yourself with a simple tool
Saw blade sharpener.
In the future, it can be used for self-sharpening on a machine or provided as a sample for companies providing such services.
Additionally, it is recommended to compare the obtained data with the reference data. In longitudinal cut saws, the rake angle is typically 15 °.25 °. For transverse models, this figure ranges from 5 ° to 10 °. On the 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.
How to sharpen a soldered saw blade at home. choosing a machine. How to sharpen a circular saw with victorious soldering with your own hands at home? How to determine the sharpening angles?
Sharpening circular saw with victorious surfacing part 1
How do I sharpen a saw with victorious surfacing I would very much like people who put a dislike argument
How to sharpen saw blades yourself with a simple tool
It is very easy to sharpen carbide discs with the help of the simplest device, and such discs serve times
In the future, it can be used for self-sharpening on a machine or provided as a sample for companies providing such services.
Additionally, it is recommended to compare the obtained data with the reference data. In longitudinal cut saws, the rake angle is typically 15 °.25 °. For transverse models, this figure ranges from 5 ° to 10 °. On the 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.
Manual way
Special machines for sharpening saw edges are rarely used in a domestic environment, because their cost is high. Therefore, in the absence of such a device, you can cope with sharpening with improvised devices, for example, an angle grinder. In this case, it is forbidden to hold the circle in your hands without fixing it with anything. Otherwise, it will not be possible to achieve a sufficient cutting angle for further work with the material.
To securely fix the circle in the correct position, use a flat stand.
- The surface of the stand coincides with the level of the axis of the grinding wheel;
- On it, the gear wheel is placed in such a way that the sharpening plane becomes perpendicular to the saw blade;
- The design of the device is complemented by a swivel joint.
The stand will help to comfortably position the saw blade for processing against the abrasive material. Before starting work, clear markings are carried out. A colored marker is used for this. They draw a mowing line, which will allow the element to be sharpened at the desired angle. The vise will help secure the disc to the surface.
Sharpening disc for circular saw angle grinder:
Types of cutting teeth
There are four planes on the surface of the teeth. front, back and two side.
At the moment of intersection with each other, they create a single cutting edge, due to which the sawing of surfaces occurs.
There are several forms of teeth:
- Straight tooth. Most often it is used only for a quick longitudinal cut. During such work, quality and accuracy are practically unimportant.
- Oblique tooth. The back plane of such a part is tilted to the right or left. On saws, these teeth often alternate, which is why they are called “alternately cut”. These teeth are most commonly used in tools. The size of the corners can be different, this is due to the coating of the treated surface. wood, chipboard, plastic. They are used for longitudinal and transverse movements. The large angle of inclination on the tools is used when cutting boards with double-sided lamination. This helps to avoid chipping of the material. The larger the chamfered corner, the easier the saw will cut through the surface. But this greatly increases the likelihood of tooth breakage. On some products, the teeth are inclined not only at the back, but also at the front.
Tools
It is allowed to sharpen the saw with your own hands only when using special devices. For this, there is a grinding machine that helps to carry out the process on an automatic machine, and not manually. Then the result becomes more accurate.
In addition, other improvised devices are used for sharpening:
- Mounting vise;
- File;
- Piece of wood.
It will not work to replace the listed devices. If at least one of them is not available, then sharpening will not work.
How to determine wear?
Checking the saw blade for wear is an important issue that should be given special attention. Deep damage leads to the inability to sharpen the circle. There are three main signs by which you can understand that the saw needs to be sharpened or replaced:
- Excessive heating of the protective cover and formation of smoke. The circular saw has a special cover that signals when the saw is blunt by heating. In especially difficult situations, smoke may appear from it.
- Sometimes the saw device involves a mechanical feed (if you need to adjust the pressure with your own hands). In such a situation, wear can be noticed if the pressure has to be increased.
- If carbon deposits and strong unpleasant odors form on the workpiece when sawing wood.
All situations described above tell the user that the device should be sharpened.
How to determine the sharpening angle of a circular saw
The best option is to have an original template, according to which you can correct the geometry of the cutting edge. Often it is made of thin-walled stainless steel, 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 sharpening at home
When working with a disc, the main thing is not to spoil the cutting surface, and this can easily happen if the hand trembles, the feed angle is violated. In order to avoid negative consequences, you should study the sharpening methods, and then everything will turn out right. Distinguish between a manual method of restoring cutting elements of a circular saw and a method using sharpening equipment.
How to properly sharpen a circular saw blade
Saw blades should be sharpened regularly to avoid damage to the building material. We will tell you how to properly sharpen a saw blade with and without solders, what equipment and tools to use.
The disc tool for sawing wood is always useful in construction. The circular saw is convenient in that it allows you to quickly cut the material with minimal effort and time. As for the quality of the cut, we can say that it is perfect, but only when the saw is serviceable and well sharpened. Otherwise, it is even dangerous to work with such a tool, so you should sharpen the circular saw.
Determining the need for a sharpening operation is not difficult: a blunt tool cuts the workpiece poorly, which immediately catches the eye. There are two options here: either send the disc to a workshop, which is not always beneficial in terms of time and money, or sharpen the circular saw with your own hands. This may seem daunting at first glance. But if you delve into the essence of the saw device in more detail, it will not be difficult to perform tool maintenance at home.
General rules for sharpening a circular saw
- First of all, the main faces are processed, of which the front wears out more.
- In extreme cases, with strong wear of the side faces, they are corrected.
- At a time, remove no more than 0.15 millimeters of the saw metal thickness.
- When finishing the edges with an electric tool, overheating of the metal is not allowed, in which case its properties deteriorate.
- To ensure the maximum service life of the saw, when it can be sharpened up to 30 times, both sides should be sharpened: both the front and the back, removing the same amount of metal.
- It is not allowed to sharpen circular saws with tools not intended for this, for example, an angle grinder and a disc for cutting metal.
After carrying out the basic sharpening operations, you can refine the teeth with fine sandpaper. The quality control of the sharpening of the tool takes place in working conditions If everything is in order, the material will be cut clean, smooth, without visible defects and blackening.
Types of circular saw teeth setting
The complexity of the wiring 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 set circulating saw setter. Each tooth should be started from the middle of its size. For wood materials of different density, the degree of setting the teeth should be different, but without going into details, we can say that they are bred wider for sawing soft species than for hard ones.
There are three main wiring methods:
- Stripping type wiring. This method boils down to the fact that the tooth after two remains in its place without change, the rest are rejected in different directions. This saw preparation is good for working with solid wood.
- A variant of the classic setting, when the saw teeth alternately move to the right and then to the left. This versatile method can be used for almost all types of saws.
- The so-called wavy layout, a distinctive feature of which is the retraction of the teeth not at a strictly defined distance from the center, but at different distances with a deviation of 0.3-0.7 millimeters.
The main sharpening angles of circular saws
The front face, the one that first cuts into the workpiece in the direction of the saw movement, forms the main cutting edge with the rear face. The angle at which the leading edge meets the material is called the Y-angle (angle of attack). The angle between the back face and the front face is the taper angle. If you subtract the rake angle and the taper angle from 90 degrees, you get the clearance angle.
In practice, it is important to observe these angles when sharpening for each type of disc. It is according to the front angle that the saws are divided into types:
- Longitudinally cutting where the rake angle should not go beyond 15-25 degrees.
- Transverse cutting, where it is permissible to sharpen the front face of the tooth at an angle of 5-10 degrees.
- Universal discs, which are easy enough to cope with both longitudinal and transverse cuts, their rake angle should be maintained in the region of 15 degrees.
The angle of the bevel 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.
When to sharpen a circular saw
There are very definite signs by which one can judge the state of the instrument. Sharpening saws is necessary when the following is clearly manifested:
- During operation, smoke appears, a specific smell of burnt wood, the casing covering the saw teeth begins to heat up quickly.
- When moving the tool along the workpiece, you need to apply significant efforts, as if to push the saw forward.
- After cutting the material and visual inspection of the sawn edge, black carbon deposits or a lot of chips, fiber scuffing, chipped areas are visible.
- A close examination of the saw teeth with a magnifying glass shows that the cutting parts are not sharp, but rounded edges.
All this requires an immediate cessation of work, otherwise there is a great risk of damage to the material and wear of the circular saw to such a state when sharpening will no longer help it.
How can you sharpen a circular saw
- Special wheels for sharpening saws, made on the basis of diamond abrasives.
- A regular file for sharpening a saw, but you also need to have a vise to secure the saw and a block of wood to use as a guide.
- Processing on professional equipment is the fastest and highest quality way of sharpening, but it requires large material costs for purchasing a tool.
Manual way
It is possible to independently sharpen the teeth by hand using a file, so that it is of high quality, if they do not have a bevel, that is, the surface of the front face is perpendicular to the surface of the blade. The process looks like this:
- A block is prepared from dense wood with a cross section of somewhere 50×50 mm and a length of 100 mm. The sides of the bar should be located strictly perpendicular to each other.
- Mark with a marker any tooth that will be reportable and the first to be processed.
- The saw blade is clamped in a vice together with a bar so that the front edge of the workpiece is flush and in the same plane with the surface of the bar (the bar in this case acts as a file guide).
- 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 to be treated and at the same time sharpening is carried out to the bar and methodical movements back and forth.
- So each tooth is gradually sharpened, monitoring the state of the bar and, when working out its surface, slightly shifting the plane.
Machine use
With the help of a special machine, circular saws can be sharpened very easily and quickly. The main thing is that you do not need to monitor the angle of the disc feed. Having set it once, the operator only has to move the teeth into the processing area and make light pressure of the tooth plane against the rotating diamond disc.
Such equipment can be used for sharpening carbide-tipped circular saws and conventional circular saws. The simplest machine for grinding operations of circular saws has the following structural elements:
- An electric drive with a grinding wheel mounting system is a stationary part of the equipment.
- A stand that moves along the guides. its task is to feed the saw blade into the processing area.
- Saw blade holder on a stand, which is designed to hold the blade in a constant position when it is fed to the sharpening wheel.
If you have additional questions on the topic of sharpening saws or you have your own experience in carrying out such operations, please respond in the comments! Your comments are important to us!