Circular saw blade replacement

What can be cut

You can use circular electric saws for longitudinal and cross-cutting of wood. both sawn timber (boards, lining, bars), and beams and logs. But it is not a hand-held circular saw, but a stationary circular saw, that can work with logs. A chain saw is more suitable for a hand tool.

Circular or circular hand saws are one of the most versatile tools

In addition, a hand-held circular electric saw can cut any sheet material. fiberboard, chipboard, OSB, plywood. By changing the disc, you can dissolve sheet metal (profiled and smooth), you can saw rebar and other metal products. It is also possible, with the right choice of disc, to cut ceramic and some types of paving slabs, plastic products, slate, drywall profiles, non-ferrous metals. A truly versatile tool loved by many craftsmen.

The only work that is undesirable to do with this tool is to cut metal tiles. Any manufacturer must indicate that the use of circular saws is unacceptable, otherwise the material will be removed from the warranty. The fact is that during operation many hot sparks fly, which burn out the paint and varnish layer. As a result, after a few months on the surface, in those places where the paint layer has been burned out, multiple rusty spots appear. The rust then spreads rapidly throughout the roofing material. Therefore, it is better not to use circular saws for cutting metal tiles. For this job, metal scissors are more suitable. manual and electric.

This is what this tool looks like

How to replace a disk?

When repairing, as a rule, several types of materials are used, which require not only cutting, but also milling. And different products need different attachments.

This moment leads to the need to replace the wheel with a cutter.

  • In order to perform this operation, you must first make sure that the device is disconnected from the mains. This point is critical to avoid serious injury. When changing a circle, even an experienced craftsman can accidentally press the start button, and the health consequences will be dire. Therefore, when working with cutting electrical units, it is necessary to strictly observe all the rules of safe work.
  • Next, you need to prepare a hexagon. It unscrews almost all the bolts on circular saws, both foreign and domestic. Using this key, you need to unscrew the fastening bolt of the protective plastic casing, turn the guard up and tighten it again, but you can not tighten it tight.
  • Next, you need to insert the hexagon into the mounting bolt of the shaft on one side, and on the other, press the lock button of the same shaft. Then the bolt must be unscrewed, removed the washer-stopper and the disk behind it. It must be changed to a milling cutter and all the steps must be done again, only in the reverse order. First, a washer is placed on the nozzle, then the bolt in the center is manually screwed in and the structure is clamped with a hexagon while the shaft lock is pressed.

After fixing the cutter, you need to check the reliability of the fastening by small longitudinal staggering of the nozzle. If everything is securely fixed, then you can continue to work.

Thus, when choosing an attachment for a circular saw, it is necessary to start from the quality and properties of the material for cutting, as well as the technical characteristics of the saw and the saw blade itself. For low-power, mostly hand-held circular saws, you should not choose blades with too many teeth. This can lead to overheating of the engine and costly repairs.

In the next video, you will find an overview of discs. 24 and 60 teeth.

How to Change the Blade in a Circular Saw

Types of discs

The size of the discs that are installed on the tool depends on the traction power of the electric motor. You can set a slightly smaller size, but a larger one is undesirable: work with overload quickly destroys any tool.

But dimensions are far from everything. Each disc has teeth. These teeth have different shapes, heights, and are located at different distances. It is by these parameters that the cutting element is selected for each type of material.

There are discs with a different number of teeth.

The general rule when choosing the height of the tooth (and setting the cutting depth): the cutting edge should protrude 1.5-2 mm above the material. Then it will go “like clockwork”. Also, according to the shape of the teeth, there are such recommendations:

  • For thin materials, choose discs with a large number of teeth (60-80 pieces). They wear out faster, but the cut is neat.
  • For coarse cuts and thick material, use coarse-toothed discs (24 pieces).
  • For cutting across the fibers, use discs with frequent teeth, along the fibers. with rare.

The angle of inclination of the teeth is also important.

When choosing a blade, pay attention to the slope of the teeth. For fast cutting, sharpening with a large positive slope is suitable, for slow and accurate sawing. with a slight negative angle, or an equally small positive angle. details:

  • For cutting along wood grain, it is best to use a blade with a positive tooth slope. For fast sawing, an aggressive slope is used. about 20 °, for medium speed. from 5 ° to 15 °. With this shape, it turns out that the teeth pull the material under the blade, and therefore the cut goes quickly, but it is very difficult to control the speed.
  • For working with hard materials, either a small positive slope is used. up to 5 °, or the same negative value. With this sharpening, it is easier to control the feed rate of the material as the material is not caught by the teeth. This mode is safer, albeit slow.
Read more:  The Difference Between A Circular Saw And A Circular Saw

There are many more different cuts and notches on the body of the saw blade. Their main purpose is noise reduction, load compensation and runout elimination.

To prolong the life of the saw blade, super hard alloys are applied to the cutting edge. Also, to extend the service life, the discs are covered with a protective layer, which reduces friction against the material being cut and protects the metal from damage. The protective coating for discs is:

  • teflon;
  • aluminum;
  • nickel.

The thickness of the disc can also vary. It is clear that in order to withstand the load, the thickness of the metal must be solid. But this increases the cutting width and the amount of wood that turns into shavings. The standard cut size is 3.2 mm, but in order to ensure the normal rotation speed of such a disc, the motor power must be about 2.2 kW. Since not everyone has such units, the discs began to be made thinner, but at the same time harder alloys were used. So the benefit is twofold: less powerful circular saws can be used for cutting serious materials, and we get less waste as a result.

Replacing a saw blade on a circular saw

When the word “saw”, most people who independently carry out repair work around the house have an image of a hacksaw. And this is true, because such works once began with her. However, progress has made great strides forward, and now the best assistant in repairs is a circular electric saw. It significantly reduces labor costs and increases the speed of work. With this tool, you can cut various surfaces and materials.

But for its functioning, nozzles are vital, without which cutting is impossible. These attachments are called saw blades.

Main settings

Consider the most important characteristics of the discs, which will allow you to choose the necessary attachment from a huge modern assortment.

  • Manufacturing company. Manufacturers of such attachments are often specialized tool manufacturing enterprises. Therefore, firms may pay less attention to the quality of components, focusing on technology. But the same cannot be said about well-promoted brands such as Bosch or Makita, which not only value their reputation, but also have the opportunity to use better quality raw materials and modern processing technologies. Therefore, one of the main parameters of saw blades and milling cutters is the brand.
  • The next important parameter that determines the capabilities of the sawing nozzle is the size of the circle, or rather, its outer and bore diameter. When evaluating this criterion, it is necessary to worry about the calculations in advance and clarify the required cutting depth, which will become the measure of the outer diameter. But when choosing, it is also necessary to remember about the size of the tool and its protective casing. These dimensions can make it impossible to install a large diameter disc, since removing the protection is unsafe and not always possible.

The rim must be identical to the size of the shaft. This is necessary for the correct operation of the equipment and the absence of overheating of the circular saw motor.

This is possible if the inner diameter of the disc is larger than the circumference of the shaft. Indeed, after attaching the disc, it will create an imbalance in the tool and, as a result, a high level of vibration. Depending on the tool model, the diameter can range from 16 to 32 mm.

  • The number of teeth plays an important role in the quality and precision of the cut, since it determines the number of cutting edges. The more of them, the clearer the line was cut. Such nozzles are available with a large (about 90 pcs.), Medium (40-80 pcs.) And small (up to 40 pcs.) Number of teeth.

How To Change Circular Saw Blades

Medium-type discs can rightfully be called universal. They can cut almost any material both horizontally and vertically. Both hard and soft types of materials lend themselves to cutting.

  • When considering saw blades, you can also highlight such criteria as the shape and angle of inclination of the tooth. The first is responsible for the ability to cut a particular material, and the second. for the type of cut. So, it is easier to perform longitudinal cuts with a disc with a positive slope of 15 to 20 degrees, and it is better to cut dense materials with a nozzle with a negative slope from 0 to 5 degrees. There is also a standard tilt type that is considered universal.
  • As for the teeth of the disc, they can be universal, flat, replaceable, have the form of a trapezoid or an increased inclination. A blade with a flat cutter is good for side cuts in hard types of wood, with a replaceable one for cutting softer types of wood and Fiberboard. Trapezoidal teeth cleanly cut soft materials such as plastic.

The teeth with an increasing slope are used for products that can easily split during operation. Universal ones are used in almost any case. They are great for occasional non-specialist home use.

  • And the last important criterion is the thickness of the product. It depends on it how wide the cut will be. The wider it is, the more material is lost in the process. The thinner the disc, the more it is susceptible to deformation and overheating.

All of the above technical characteristics of the saw blade are indicated on it. Typically, marking is performed in the form of appropriate, intuitively understandable to the user pictures with the necessary numerical data.

Saw blades are divided into two types: carbide and monolithic. This division describes a difference that is immediately apparent. The fact is that on some discs the cutting part is soldered to the teeth, and some are simply a single product (monolith).

Reviews Makita 5008MG (Makita)

Good saw. Lightweight, quiet, reliable, no vibration. With her help he built and decorated the house.

Ideal for boards no thicker than 50 mm. Has been working for 2 years. Everything is fine, only the hole for the sawdust removal is clogged.

A good tool, lightweight, you can work with one hand, the assembly is good, the disc included is excellent, thin. But it burned out after a year of easy operation, that is, it is not for professional use.

Read more:  Which Disk is Better For A Circular Saw

How to replace a circular saw blade

If you do not know how to replace a circular saw blade I suggest watching this video. Disk replacement

Extraneous sounds appeared during operation

Grinding and other abnormal sounds can cause faulty bearings or gear and shaft gears with worn or broken teeth. In the following figure, the arrow shows where the armature gear is.

The gear located on the motor shaft can come off when the saw gets stuck in hard or loose wood. Usually, the gear wheel does not suffer in this case. To eliminate this damage, you will have to completely change the engine anchor. In the event of bearing breakdowns, they can be easily removed with a puller and replaced with new ones.

Tool disassembly

Almost all malfunctions of electric circular saws cannot be eliminated without disassembling the device partially or completely. Complete disassembly of an electric hand saw using the example of an Interskol unit is carried out in the following order.

  • Unscrew the angle and depth adjusting screws attached to the foot of the machine.
  • Press the gearbox shaft stop button and use the hex wrench to unscrew the bolt holding the saw blade.
  • Pulling the lower guard to the side, remove the circular disc.
  • To remove the support sole, first unscrew the fasteners on its underside.
  • Next, using two screwdrivers, remove the Sieger ring, which locks the rod on which the sole turns, to change the angle.

Insert a screwdriver into the gap between the body of the shield and the sole, then push it aside and remove.

  • In the next step, unscrew all the fastening screws located on the upper casing of the unit.
  • Also remove the screws holding the movable saw guard.
  • Disconnect both protective covers from the saw.
  • Using an open-end wrench, unscrew the bolt holding the riving knife and remove it.
  • Unscrew the stem holding the movable casing mechanism and disconnect all its elements.
  • Next, disconnect the unit’s gearbox by unscrewing 2 screws.

  • When the mechanical part of the device is disassembled, you can start disassembling the electrical part of the device. Unscrew the fastener holding the engine cover and remove it.
  • Removing the cover reveals two electric brushes. If they need to be completely disconnected from the engine, it is recommended to use a marker to mark one of them, as well as the place from where it was taken.
  • Next, you should unscrew the screws with which the motor housing is attached to the gearbox housing.
  • After unscrewing the fasteners, disconnect both nodes.
  • In the detached part of the motor housing, you will see the stator coil.
  • Next, you should unscrew all the fasteners from the handle of the unit. But before disconnecting it, you need to remove the rubber pad by prying it with a screwdriver.
  • Removing one half of the handle, you will see the soft start module and the start button.

    This concludes the complete disassembly of the circular saw.

    Saw not picking up power

    If, while using the unit, you notice a drop in its power, then it is first recommended to check the voltage level in the network. Sometimes even a slight drop can negatively affect the power of the power tool.

    Also, a loss of power can be observed when the armature bearings or the gearbox bearing are worn out. In this case, extraneous noises will be heard that were not previously characteristic of this unit. By their localization, you can determine where the problem bearing is located. in the gearbox or engine. To replace the bearings, you will need to disassemble the saw blade. How to do this was described above.

    If during the operation of the unit, extraneous noise is not heard, and the engine still develops speed and power poorly, then pay attention to its manifold. You can usually see a circular spark (ring of fire) on it. This can be due to the turn-to-turn closure of the armature coil or the accumulation of dirt between the collector lamellas.

    Open the motor housing and carefully inspect the manifold (the place where the brush electrodes slide). It consists of parallel strips (lamellas). There is a small gap between them. When this gap is clogged with conductive graphite dust formed during brush wear, a short circuit occurs between the lamellas, and a burning ring appears around them.

    The problem will be solved by replacing worn brushes and cleaning the gaps between the lamellas with a toothbrush, cotton wool and alcohol, followed by polishing the plates with fine sandpaper.

    In some cases, a power drop can be caused by a faulty start button. If a tester check has confirmed its failure, then the part should be replaced with a new one, since it cannot be repaired.

    Shaft jammed during operation

    This malfunction can occur when, for any reason, the stopper is pressed while the tool is running. It is designed to secure the shaft when changing tooling and should be used after the motor has come to a complete stop. Otherwise, the stopper rod will break and debris will enter the engine, causing seizure. There are often cases when this leads to deformation of the armature shaft. Also, a consequence of pressing the stopper can be a split in the gearbox housing, the fragments of which can damage the gears and cause them to jam. To solve the problem, you will need to replace the armature, stopper, drive (large) gear of the gearbox and its housing.

    In some cases, the gearbox can jam when the bearing is completely destroyed.

    How to choose

    Any instrument is divided into home, professional and industrial. Industrial equipment in the household is useless, but you cannot say anything professional. Yes, it is more expensive than what belongs to the household class, but the characteristics and, more importantly, the labor resource is incomparably larger. Therefore, if possible, try to select an instrument from their professional series.

    It should be comfortable for you to hold the instrument: you will need to handle it and control its position

    Read more:  Hand circular saw which to choose

    On the construction site, the quality of the sawing and the speed at which the tool can cut is important to us. The speed and quality of work with a manual disk electric drive is influenced by the engine power and its rotation speed. The rotation speed can be from 1800 to 5000 rpm, the power is from 500 W to 2.5 kW. It is clear that the higher the speed and the more powerful the motor, the higher the cost of the saw. Since the energy consumption is not very high, they are plugged into a regular household 220V network.However, there can be significant differences when operating at maximum speed.

    It is very good if the tool has the ability to adjust the speed. This will allow you to choose the best mode for each type of material. Electronic overload protection, which is usually implemented by the function of maintaining constant speed under load, will not be superfluous.

    Not so long ago, battery-powered circular hand saws were discovered on the market. They cost more than the same networked devices, but that’s the price of batteries, but they require a lot of capacity.

    By changing the angle of the platform, you can make not a perpendicular, but an inclined edge

    In addition to the electrical parameters, many little things are important, which nevertheless expand the tool’s capabilities. It is so useful if the platform allows you to change the angle of the incision. You can make the rib at a right angle. It is equally important that the depth of the cut can be adjusted. this way it will be possible to work with materials of different thicknesses. In general, the depth of cut is also one of the key parameters influencing the selection. Ultimately, it determines the maximum size that can be cut. Professionals prefer tools that can cut 100 mm or more. The minimum value is 40 mm. this parameter is for household models.

    Occasionally pay attention to the way the platform is created. There are platforms with printing, there are cast ones. The latter are considered more reliable. But this characteristic is not so important for home use: the load on the platform will not be so great.

    What is not inappropriate. this is a hole in the housing for the exit from sawdust and dust. To reduce the amount of contamination during operation to a minimum, you can use a hose from an industrial vacuum cleaner.

    Choose not only electrical characteristics, but also the quality of workmanship of every detail

    design

    The design of the circular saw is simple and therefore, perhaps, so easy to use. It consists of:

    • electric motor;
    • saw blade;
    • a body that has one or two handles;
    • a protective cover that covers the disc from above and below (the lower part is movable and automatically removed during operation);
    • A platform that allows you to install and hold the drive in the right place;
    • wedge-shaped knife that prevents the disc from getting stuck in the forest.

    The saw blade is attached with one or more screws to the motor shaft. Thanks to this, replacing the disk takes a few minutes. You just need to unscrew one or more bolts, remove and place the disc, putting the fasteners in place.

    The structure may be slightly different: instead of a battery, there is usually an electric cable

    The electric motor is attached to the platform. On more expensive tools, this mount is movable, which allows you to change the cutting angle. This angle is usually between 0 ° and 45 °. It differs from different manufacturers. Most often there is a scale with fixing screws. The angle is set, the screws are tightened, which gives the cutting blade a certain tilt.

    How to remove a blade from a circular saw?

    To properly remove the canvas, you need to adhere to the following sequence:

    • For your own safety, be sure to disconnect the power cord from the mains or remove the battery
    • For a more convenient replacement, it is required to install the tool on a flat, hard surface
    • To start unscrewing the bolt, you must press the locking spindle, which blocks the rotation of the disc when unscrewing
    • Unscrew the bolt using the special wrench included in the kit
    • Pull out the bolt and remove the washer holding the saw blade
    • Move the lower guide arm to raise the guard
    • Remove the saw circle

    How to change a circular saw blade?

    The new canvas must be installed in the following sequence:

    • Clean the pulley and protection from accumulated dirt, sawdust.
    • Check the correct direction of the saw teeth in accordance with the arrow on the guard.
    • Put the blade on the pulley and lower the lower protective shield.
    • Install the retaining washer and tighten the bolt. Tighten it again with the recessed locking spindle.

    Removing and replacing the disc on a circular saw

    Due to the competition in the market, the choice of electrical tools is constantly increasing, and are becoming more affordable. Now women are happy to give them to men on February 23rd, or relatives and friends for their birthday. Almost every second household man has his own circular circular saw.

    Over time, the circles fail (dull or break), they must be replaced depending on the material with which you need to work. For example, you cannot cut wood with a metal cutting blade. Therefore, the ability to correctly and quickly remove the disc, put a new one is necessary for everyone.

    Washer for circular saw?

    A flange or washer holds the disc securely in place. On various saw models, both a flange separate from the bolt and soldered to it are used.

    The main function of the hold-down washer is to evenly press the saw blade against the pulley. A correctly installed washer must sit symmetrically on the circle.

    The main and main rule when replacing a blade on a circular saw is to completely disconnect the tool from the power supply. To avoid accidentally injuring yourself with the saw teeth, it is best to use gloves.