Choosing A Saw Blade For A Circular Saw: Types And Purposes

For cutting wood, laminate, plastic and non-ferrous metals, we most often choose a hand-held circular saw or a circular saw . Today it is one of the most demanded tools for DIYers and professional builders. The efficiency of this tool is directly dependent on the disc. You may ask why this is so, because all saws already come with discs from the beginning and what could be wrong? As a rule, not every complete disc may be suitable for the job that you have planned. And in the event that you nevertheless start cutting materials with a tool that is not intended for sawing them or is not at all intended for this direction, you risk injuring yourself and others, disable equipment and spoil the workpiece.

A disk is a consumable and, depending on the specifics of the work, its replacement is not uncommon. Users often ask questions: “How to choose a blade for a circular saw?”, “Why do you need carbide brazing?”, “Which blade cuts without chips?” etc. There are a huge number of similar questions. Therefore, in this article I will try to give answers to the most basic ones – what is a saw blade and how to choose the right one for a circular saw.

The quality of the cut with a circular saw will always be at the highest level. By the way, many performance parameters of the saw affect the accuracy and precision of the cut. Not the least among them is the saw blade – it should not be blunt, made of good metal, fit in size.

You will have to change the disk often if the work is professional and daily. In order for the device to make high-quality, even cuts, to work without interruption for a long time, you need to carefully select consumables. The quality of the work performed, as well as the service life of the device itself, depends on the right choice. Therefore, the question of how to choose a blade for a circular saw is not so commonplace.

In this article, you will learn how important it is to choose the right disc of the right size (and the role is played not only by the external size, but also by the bore). I will tell you why the teeth are made in different shapes, why their number on different discs is different, and which manufacturers produce the best discs for circulars.

 

A proven manufacturer is the key to tool reliability

Any sawing tool is a traumatic, high-speed cutting equipment, where it is imperative to adhere to safety rules during work and always monitor the cutting disc, since all the success and safety of work depends on it. Therefore, the first point we will consider manufacturers.

Each manufacturer must guarantee the disc:

  • durability;
  • balance;
  • heat resistance;
  • endurance under stress.

Today, a fairly large number of different brands are represented in Ukraine – European, American, Chinese and Ukrainian manufacturers. Here we can safely divide them into two categories – companies that produce professional consumables and more budgetary (affordable) for household purposes or for one-time work. In order to understand how high-quality disc you are getting, try to pay attention not to the beautiful packaging of the manufacturer, but to the presence of carbide soldering. Below in the picture you can see the comparison, as it is done on a more expensive and cheaper disc .

If you ask what, in fact, is the difference, I will answer – manufacturers of high-quality equipment perform laser soldering when installing carbide (victorious) teeth. And some manufacturers of inexpensive goods, in fact, do not even use soldering, but can even use the usual gluing of a disc under a high pressure. Or another option – there is a soldering, but it is made extremely poorly. What is the risk of this while working? After installing such a disc on a circular saw, we can get a “helicopter” or, more simply, the disc makes a “figure eight” during rotation. The cut may turn out to be uneven, with chips. And if during operation you overheat it, then these solders will simply chip. In this case, there is the possibility of harming yourself and the tool. If we talk about trusted manufacturers, I recommend Bosch, DeWalt, Metabo,

Are there discs for all types of work?

Many circular saw owners who are going to purchase saw blades wonder if there are saw blades that do all types of tasks at once? There are such discs, but their price is very high and often the main parameters (the body of the disc, its thickness, the presence of soldering) are greater than those of circles for individual materials, and this significantly increases its weight, will require a sufficiently high power of the circular saw motor and the bore … Therefore, it is possible to find such a tool, but it is not always affordable and not always your tool will be able to work correctly with such a consumable.

There are two main types of discs:

  1. Monolithic disk. It can be presented in two versions: with sharp, even teeth and with slightly curved teeth with a wide back. The first option is suitable for both soft and hard wood, and can perform both cross and longitudinal cuts. The second option is more suitable for softwoods. Monolithic teeth are not entirely reliable, they quickly become dull.
  2. Carbide wheel. With saw blades with this type of teeth, the material is cut evenly, of high quality, and most importantly, the teeth last much longer, sharpen with less frequency. I will describe the purpose of the teeth below.

What do you need to know first before choosing a saw blade?

Before you start buying a circular saw blade, you should know a few nuances:

  1. For what type of work do you want to buy a disc – it will be a longitudinal or cross cut, wood, aluminum or plastic, the work will be one-time or for continuous use.
  2. Always match the blade to the maximum size that can fit on your instrument. Here you need to know several parameters – the outer diameter, the diameter of the bore, the thickness of the disc and the number of teeth. I will give an elementary example – your saw uses a disc diameter of 250 mm with a fit of 30 mm, and you buy a disc with a diameter of 254 mm and to install this disc you need to remove some protection elements, and this is primarily contrary to safety precautions.
  3. If the inner diameter of the disc you are purchasing may not match the bore on the shaft. For example, the diameter of the disc is 30 mm, and the fit on the shaft is 20 mm. Don’t be in a hurry to get upset – most discs come with adapter rings, thanks to which the disc will fit perfectly and there will be no unbalance during operation.
  4. Always build on the power of your saw. After all, the more teeth, the cleaner the cut will be, but this, unfortunately, will give a sufficient load on the tool and at low power the engine can simply burn out.
  5. Manufacturer. I already talked about this at the beginning of the article. Try to pay attention to models of not the lowest price range.

Criteria for choosing a disc for a specific type of work

When choosing a saw blade for a specific operation, you need to pay attention to some criteria:

  • cutting element design;
  • the size of the outer disc diameter;
  • the number and type of teeth in the saw blade;
  • tilt angle;
  • web thickness.

For example: the figure shows what forms of teeth are, what parameters you need to pay attention to and what to choose for such work.

 FZstraight tooth TF Z (HLTCG)trapezoidal tooth alternating with straight tooth
FZ Nstraight tooth with negative rake angleTFZ N (HLTCG N)trapezoidal tooth alternating with a straight tooth with a negative anterior angle
LFZstraight tooth with chip control
 WZ (ATB)variable tooth DHZstraight hollow tooth alternating with gable hollow tooth
WZN (ATBN)variable tooth with negative rake angleDHZ Nstraight hollow tooth alternating with gable hollow tooth with negative rake angle
LWZ (ATB Z)variable tooth with chip control
 

TZ

trapezoidal tooth

 

KON

tapered tooth

  1. The rake angle affects the cut quality. The larger the rake angle, the more force the tooth enters into the workpiece and increases the cutting force and speed.
  2. Positive and negative tooth angle. A (positive) – Fast, light cuts, great for straight cuts, wood, works well with hand-held circular saws. Thanks to this shape, it creates sufficient force to press the tool against the workpiece. The negative tooth is designed for more difficult cuts, well suited for cutting plastics, soft metals and certain types of wood. Often used with miter saws.

Now I will briefly tell you about the shape of the tooth itself, and what it affects:

  • WZ is a changeable tooth. Excellent for both hard and soft wood, spherical and polymer materials, gives a clean cut, is easy to sharpen and, in the presence of a negative tooth, is recommended for cross-cutting;
  • FZ – flat tooth. Ideal for fast and deep cuts in solid wood;
  • FZ / TZ – ideal for cutting aluminum, copper, brass and plastic profiles, as well as panels with different types of coatings, MDF and other wood materials. Gives a perfect cut;
  • FZ / FA – blunt flat tooth. It is mainly used in construction and professional table saws, as well as in hand-held saws of the same class. It is widely used for construction timber, formwork, wood with nails or all kinds of solid structures. This form is considered one of the strongest;
  • DZ / HZ – triangular / curved tooth. The optimal choice for furniture production, especially well cuts wooden boards coated on both sides. Does not chip on the surface during the cut.

These types of teeth are the most common and are found in most manufacturers with the exception of budget TM. Also, do not forget that not only the shape of the tooth will affect the speed of your work, but also the diameter of the disc, its thickness, as well as the number of teeth. For a longitudinal fast cut, a disc with an average number of 24 to 36 teeth will be sufficient, and in order to get a clean, high-quality cut not only of ordinary wood, but also of furniture parts or other types of materials, the number of teeth, depending on the diameter of the disc, can be from 48 to 100 pcs. I emphasize again – before choosing a blade, the first thing you should pay attention to is the power of your saw.

If you have any questions after reading the article, leave comments below. I will be happy to answer them!

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