Circular saws for wood sizes. How to choose wood saw blades for a circular saw. Radial and axial runout

When mastering the skill of making precise and neat cuts with a circular saw, start by selecting a good blade. The correct working equipment will allow you to cut various materials efficiently and quickly, reduce waste losses and minimize the risk of injury.

All-metal discs are no longer common, although they have previously proven themselves well in amateur workshops. They get dull quickly, however, they are easy to sharpen yourself, and they can withstand many sharpenings. Saw wheels with carbide teeth are more expensive, and their cutting edges are more difficult to restore. But they last longer, cut better and justify the money spent before replacing them with new ones, even without sharpening.

Remember the characteristics of your instrument

Start selecting a blade by viewing the technical features of a circular saw, remembering three indicators:

The seat size is the diameter of the power shaft corresponding to the internal hole of the saw blade.
The permissible outer diameter of the working nozzle, limited by the size of the protective casing.
Spindle rotation speed is a value set by the manufacturer, always less than the maximum possible number of revolutions for the disk used.

It is permissible to install a disc with a “non-native” fit through an adapter ring, which is sometimes included in the kit. You can use a consumable with a smaller outer diameter, taking into account the reduction in cutting depth. The locking pins found on the spindle of some models require the use of a disk with appropriate through holes.

Read the label

Knowing the basic characteristics of the circular saw, study the information on the packaging. It must indicate the permissible rotation speed, external and mounting dimensions. Drawn pictograms can represent intended materials, indicate cutting direction, and much more.

Advice. A manufacturer that respects the consumer applies sufficient markings to the disc surface using laser engraving. A product without identification marks raises the question: what is it and what is it made for?

The number of teeth is the main feature that determines the purpose of the saw blade and, in many respects, its cost. Blades with a small number of teeth are characterized by a high cutting speed and a “dirty” cut that requires further processing. Equipment with a large number of cutters is recommended for sawing hard materials and finishing cuts.

Saw wheels for circular saws differ from equipment for pendulum saws in the inclination of the teeth, which is explained by the different trajectory of movement of the working part in the workpiece. Discs with a negative or neutral angle of inclination used for trimming work press on the surface from above and cut down the material, while the part being cut rests against the limiter and the disk is not pulled into it. When installed in a circular saw, such a circle will repel the workpiece, become clogged with sawdust and overheat the engine - it is very difficult to make a longitudinal cut with it, especially in undried wood. The “positive” blades used for circular saws have teeth angled toward the surface and cut the material like a plane knife, pulling the wood underneath.

Useful information about the purpose of the disk can be obtained by considering the configuration of the teeth:

The straight tooth cuts through solid wood quickly but messily.
Alternately beveled cutters are suitable for any cutting direction, but are susceptible to shock loads.
A combination of flat and trapezoidal teeth prevents the top layer from splitting and is used for cutting slabs, plastic and non-ferrous metals.
Combination cutters are a sequential combination of cutters with different sharpenings that provide clear cutting edges at good speed in materials of varying hardness.
Alternating concave and triangular teeth are ideal for cutting laminate without pre-notching.
Flat, chamfered teeth coupled with wide backs can withstand cement or nails in the cutting line.

Evaluate the disk body

Make an approximate conclusion about the quality of the disc by carefully looking at its surface. On a normal saw, if you “play” it in the light, you can see grinding marks diverging in circles, indicating the calibration of a circle cut from a sheet. Low-budget equipment does not have such stripes - the whole sheet was processed (or not sanded at all) and the balancing leaves much to be desired. And, of course, the surface must be smooth - no one needs resin sticking to rough surfaces.

Radial slots located on the canvas dampen vibration, reduce noise and protect from overheating. On “expensive” circular saws, thin spiral slots are additionally applied with a laser, and the body is covered with a protective layer. The cleanliness of processing and the working life of the disk depend on the runout tolerance; for high cutting accuracy this figure is 0.15 mm. There are more accurate examples, but their use is not practical for a household circular saw.

Advice. A cheap blade wears out quickly and cuts worse, while an expensive blade cuts more accurately and lasts longer. Find your price/quality level: there is little point in purchasing “luxury” equipment for 5 thousand rubles for a circular saw of the same cost.

The actual kerf width depends on the size of the carbide insert, which affects the amount of chips removed. The thickness of the blade determines the gap between the material and the disk, which is necessary for the free movement of the saw wheel. A reliable disk is quite thick and weighty, but requires powerful equipment. A thin circle puts less load on the engine and is optimal for battery-powered models, but is “gentle” and not suitable for intensive use.

Choose a disk for specific tasks

For precise crosscuts in solid wood, decorative plywood and other panel materials, use a 50-60 tooth blade that produces an almost planed edge. For most operations, when high quality is not required, do it with a cheaper wheel with 40 cutters. Use a disk with 18-25 teeth to saw solid wood along the grain, and with a circle with 10 teeth, unravel the boards, constructing the frame of the sheathing, or carry out dismantling work in which chips do not matter.

Cut non-ferrous metals and plastics with discs with 60 or more cutters: with a negative tooth angle for a thin-walled profile and a positive one for a thick-walled one. To cut gypsum-fiber and cement-containing materials, take special wheels with 4-6 teeth, reinforced with artificial diamonds.

Do you want to get a perfect cut of furniture board immediately before finishing sanding? If your circular saw is at least semi-professional, install a 40-cutting disc with straight/trapezoidal teeth and a negative slope (designed for aluminum and laminated chipboard). Drive the saw slowly against sensitive resistance, perhaps at full power. The result will be worth the inconvenience: the cut will come out smooth - to a “zero”, and you will save time previously spent on fine-tuning the front edges.

There is no saw blade that fits every tool and can provide quality and productivity at the same time. You have to select several options, taking into account the most frequently performed tasks.

It is rare to meet a craftsman who is not involved in sawing wood. A circular saw, a circular saw, a miter saw, an angle cutter are present in garages and home workshops almost everywhere, which means that when saw blades for wood are needed depends only on time. All blades differ from each other in the material of manufacture, shape, size, tooth pitch and other important parameters on which the quality of the cut largely depends.

Saw blades

Today, manufacturers offer a fairly large range of equipment for wood processing. When purchasing it, you need to pay special attention to the selection of the cutting blade, because it determines what kind of material you can work with.

Wood saw blades for grinders and circular saws differ in their technical characteristics. Their teeth are inclined in the direction of movement, and the more of them there are on a part, the more accurate and accurate the cutting itself will be.

For an electric hand saw for cutting boards, fiberboard, you will need a knife with fine teeth (about 100 pcs.). For cutting wood with many knots, reinforced discs with 24 cutting edges are selected.

The marking of saw knives consists of 2 numbers. The first means their diameter, and the second characterizes the diameter of the landing rod. Discs that have a lower rating than that provided by the saw cannot be installed on the equipment, since between the part and the casing there will be a space into which a hand can accidentally get caught.

How to choose the right disk

When purchasing saw blades for wood, you need to pay attention to the following parameters:

for what types of work they will be used, what kind of wood will be cut;
disk series, which takes into account the shape and size of the teeth, whether there are special plates;
the design of the saw blade itself (tooth shape, slope, presence of plates, their shape, location, blade thickness);
the outer diameter must be selected taking into account the rotation speed;
diameter of the mounting hole, which depends on the type of tool;
parameters of teeth (thickness, shape, number, etc.).

Disk characteristics

When choosing a circular saw and saw blades for wood, you should immediately decide what materials will be processed and what work the tool is needed to do. Today there is a wide range of models on sale. All of them are designed for specific jobs, so their selection should be given special attention.

Dependence of disk diameter on equipment rotation speed

Saw blades for wood can have different sizes.

disc diameter up to 80 mm is used at a rotation speed of 23,800 rpm;
up to 100 mm - at a rotation speed of 19,100 rpm;
up to 120 mm - at 15,900 rpm;
250 mm - at a rotation speed of 7,600 rpm;
disc diameter 300 mm is used at 6,300 rpm.

It should be remembered that the larger the diameter of the blade, the lower the rotation speed of the saw. This must be taken into account when choosing equipment.

Dependence of cutting speed on material

In this regard, there is the following pattern:

for soft wood, it is recommended to use a speed of 50-90 m/s;
cutting of hard rocks occurs at a speed of 50-80 m/s;
cutting exotic types of wood - at 50-85 m/s;
for MDF panels the speed is 30-60 m/s;
for laminate panels - 40-60 m/s;
for simple carpentry work and chipboards - 60-80 m/s.

When choosing a tool, it is necessary to take into account that saw blades for wood have different sizes and shapes of teeth and can be used at several operating speeds.

It should be remembered that all tool manufacturers indicate the required parameters, so you can easily decide which equipment you need to choose to complete the planned work. In addition to speed, speed, thickness and other indicators, it should be taken into account that circular saws can be not only hand-held, therefore, first of all, you should determine for which tool a particular disk is intended.

Why is it important to choose the right saw blade?

When deciding how to choose a wood saw blade for a clean cut, you need to take into account parameters such as the shape and size of the teeth. Manufacturers offer several models:

Carbide, having special brazings that provide cross-cutting. The products can be used for solid wood. Use a wood saw blade for a clean cut when cutting wood fibers, chipboards, hard and soft wood. The teeth of such models are trapezoidal in shape and made of hard metals. Carbide discs with thick scoring knives provide greater working speed. They are used for machines with automatic material feeding.
Special saw blades for wood with variable teeth, scoring knives, thickness reduced for cutting. Used only for longitudinal cuts, they allow you to make a neat and thin cut. Such cloths cannot be used when working with poplar. The tooth shape is variable, inclined by 10°, straight. Such discs are used for single-shaft or double-shaft multi-rip machines and are used for soft and hard wood with a moisture content of up to 15%.
Disc with variable teeth, which can be used for radial, pendulum cutting. Suitable for hand tools. Provides high-quality cross-cutting of solid or hard, dried or wet wood. The tooth has a negative external angle, the inclination of which is 15°. A similar saw blade for wood, the price of which is from 114 rubles. - the most optimal option for construction work on the site.

Helpful information

In order to choose the right disk for woodworking, you must adhere to certain rules. Before you place an order in a store, think about what kind of work you plan to do more often.

Monolithic discs quickly become dull and therefore require periodic sharpening with teeth set. Discs with carbide-tipped teeth are more expensive, but last longer. They are difficult to sharpen, but they have a longer service life and excellent sawing quality. Today, discs of this type are the most popular type of equipment.

Blades with fewer teeth are good for rip cuts. The angle of inclination of the cutting surfaces must be positive, and the depressions between them must be large in order to effectively remove sawdust. For example, a disk with a diameter of 230-250 mm should in this case have from 18 to 24 teeth.

For a cross cut, the number of cutting elements should, on the contrary, be large - up to 48.

There are saw blades with protrusions behind the carbide brazing, the role of which is to limit the feed speed of the saw. Such discs provide a smooth and clean cut, and are protected from damage to the cutting edges by falling knots.

Typically, manufacturers indicate all the necessary information on the disc packaging in the form of pictograms. The materials with which it is recommended to work with this equipment, the direction of the cut (transverse or lengthwise), the maximum permissible speeds and the angles of the teeth can be indicated here. The value "7 neg" means 7 degrees of negative slope, and "5 pos" means five positive. Sometimes, for greater clarity, a schematic image of the saw for which it is intended is drawn on the saw blade - a miter or circular saw.

The quality of a cutting disc for wood is easy to assess by its appearance. Pay attention to the direction of grinding the disk - if you are looking at a representative of high-quality branded equipment - the marks from the grinding tool diverge radially in the direction from the mounting hole. If these traces are not present, then you are holding in your hands a fake or a “budget” option. Such blades are cut from a sheet of metal that is ground beforehand, while high-quality saw accessories are individually ground and balanced after stamping.

The shape of the teeth and the method of sharpening the saw blade are also important. The most common types of sharpening are flat, alternating bevel and trapezoidal (straight tooth). For rough cuts, flat sharpening is used; for work on chipboard, plastic and soft metals, trapezoidal sharpening is used. Alternating bevel sharpening is considered universal and is excellent for clean cross cuts in plywood, hard or soft wood.

Anyone who has a circular saw on their farm knows that from time to time the saw blade requires sharpening or replacement if the blade’s soldering is completely worn out. In the article we will look at all the main points that need to be taken into account when purchasing a wheel and the characteristics of saw blades.

Different diameters

Outer circle diameter

There are very small discs, from 150mm - these are equipped with low-power circular saws, respectively, with a small depth of cut, and the saw itself looks quite miniature.
There are saws with a large circle of 160, 180, 185, 200mm. While you can put a small circle on a large saw, you won’t be able to put a large disc on a small saw; it will touch the protection.

Inner diameter (bore)

A very important point to pay attention to when purchasing. There are several sizes of the internal hole: 16, 20, 22, 30.32mm. If you don’t know for sure, then, as a rule, this indicator is indicated on the marking of the saw, and if it is erased, you can measure the hole; measuring with a tape measure is very problematic, especially to see a difference of two millimeters (if the fit is 30mm or 32mm).
There are discs for two hole diameters at once, these come with an adapter ring.

Available in two diameters

For example: the main size is 30mm, there is also a ring that is inserted inside and we get a diameter of 20mm.

Number of teeth on the saw

There are discs with a small number of teeth (for example, 24 teeth on a 200mm disc), these are better suited for quickly sawing material, such a disc is best used when you need to quickly saw a bunch of boards and special precision is not required.
Circles with a large number of teeth are better suited for accurate cutting; the cut is smoother and not “ragged”, but it takes a little more time to cut. This will be very good for sawing plywood, fiberboard, and chipboard. It is better to have different discs on the farm, both with a small and a large number of teeth.

The slots on the saw blades serve for cooling, since when cutting there is strong friction and, accordingly, overheating of the disk.
Disc marking: usually there are three parameters. For example: 190*24*30. This means the outer diameter is 190mm, 24 is the mounting hole, 30 is the number of teeth.

Manufacturers

Basically, all discs, like most instruments, are made in China. Inexpensive ones: “Stayer”, “Ermak”, “Attack”. The more teeth, the more expensive the disc. Approximate price at the end of 2012:
A disk with a small diameter of 150 mm costs about 150 rubles, for 200 mm – 220-400 rubles.

All photos from the article

The cutting element can be the main working part of a circular saw or in the form of an additional attachment for an angle grinder. The discs come in different varieties depending on the direction of cutting and the hardness of the wood. By choosing a blade strictly in accordance with the material being processed, you can guarantee its safe operation and clean cut.

General information

Just as there is no panacea for all diseases, there is no one universal saw element for all types of woodworking. For fast, high-quality, and most importantly, safe operation, each operation requires an appropriate disk.

Before choosing a disk, you need to decide on the working material:

type of wood - hard or soft;
cutting will be done lengthwise or crosswise;
type of workpiece being processed– boards, plywood, chipboard, the presence of any coating.

While cross-cutting is best done with a disk with a negative tooth angle, for longitudinal cutting this option is unacceptable due to the occurrence of a repulsion effect, so the model for longitudinal sawing is not suitable for cross-cutting. Negative consequences can occur for the saw engine - sawdust, clogging into the interdental sinuses, creates enormous overloads on the engine.

Note!
Bouncing off the surface and, consequently, vibration of the workpiece will not only become an unpleasant sensation for you, but extremely life-threatening.
It is especially important to take this point into account when working with an angle grinder, when the chance of getting a terrible injury is especially high.

For each type of work, appropriate disks are selected, which may differ:

a series or a hint for you in a painful choice;
the type and angle of the teeth - with a positive inclination, the cut is made faster, but sloppily, with a negative inclination, on the contrary - slowly, but cleanly;
number of teeth - a large number of them (80−90) are suitable for a clean cut, but the work is slowed down by accumulating chips; the fewer teeth (10–40), the faster the work goes, the chips are removed, but the cut looks torn;

design - on a high-quality disc, grinding marks diverge from the center, i.e. each was processed separately; the surface should not have roughness, otherwise it will heat up and the teeth will quickly become dull; stiffening rings, wavy expansions and a special coating of the canvas also indicate its good quality;
outer diameter;
diameter of the mounting hole;
maximum speed;
blade thickness - a thin disk creates minimal load on the engine and can be used in a cordless saw, but it is not suitable for heavy work;
marking - on high-quality samples it is laser and contains information that is discussed here point by point.

Of course, you should know the technical capabilities of your instrument, which include:

engine power that will “pull” discs at high speeds; a large number of teeth and their negative angle;
spindle rotation speed – proportion of blade size = drive power is better not to disturb and not see the consequences;

the size of the seating pin, which guarantees a secure fit of the disk; otherwise, an adapter ring is purchased, but it is still advisable to choose the right size. For example, a 200x32 wood saw blade should be mounted on a pin with a diameter of 32 mm;
permissible outer diameter, the protective casing serves as an additional limiter.

More about saw blades

The correct selection and operation of a saw blade affects not only the quality and speed of the cut, but also human safety. So it makes sense to take a closer look at the features of popular models.

Cross and longitudinal sawing

Unlike cutting metal or stone, when working with wood, the direction of the cut is of great importance. This can be explained by the direction of the fibers; because of this, it works completely differently when cutting crosswise and longitudinally.

A 210x30 disc, or any other size for longitudinal sawing, is designed in order to cut the workpiece along the grain as quickly as possible. Among the design features, one can note the increased sinuses compared to other models (this is necessary in order to quickly remove a large amount of sawdust), as well as a smaller number of teeth.

The sharpening angle of the disk is positive, thanks to this the self-grabbing effect is maximized, that is, the saw, as it were, pulls the workpiece towards itself, which makes it easier to feed and increases work safety. If you need to cut a large volume of lumber with your own hands, this will greatly facilitate the work.

The video in this article is a short overview of the Freud carbide blade.