How to choose a blade for your circular saw

I just received my last gift car, an ultra thin CMT disc to cut for and against the grain, so in passing that I change it, I will try to explain the advantages and disadvantages of the 3 types of disc that I usually use.

This is the disc that I currently have mounted, it is the one with the largest diameter that my circular supports (235mm). Being so big and thin, it can wobble a bit in certain cuts, especially if it is not well sharpened.

Another problem that people usually have using inverted circular ones is to keep the blade square to the table, especially at a low cutting height because the clamping system of these machines is more unstable the lower the blade is and it is easier. lean due to the weight of your engine.

This problem will be accentuated as the quality of the circular decreases. With my circular this problem is almost negligible.

I’m going to make a cut so that you can appreciate the oscillation of the record that I was talking about earlier. It is not appreciated much on video and with this material, but it really exists.

Now I’m going to try the new disc with a smaller diameter, as you can see, the quick access cover makes the change quite easy. Of course, do not forget to disconnect the circular from the electrical network before handling or changing the discs.

The boot is much smoother due to its lower weight and diameter, and the cut does not oscillate at all. In addition, being of less diameter I can keep the circular in a higher position avoiding squaring problems in the cut, as explained above.

As these circulars do not have rev control, it is even more important to use the right disc for each type of job. Normally the harder the material to be cut, the lower the revolutions, so we must try to solve this problem by using thinner blades or with fewer teeth.

This is the new disc, it is 190mm in diameter, 24 teeth and 1.8mm thick. I get a 52mm cutting height and will use it mainly for woods and derivatives, such as hard plywood.

In addition, as it is thinner than the common ones, the waste of material is less and the force that the circular must exert to cut also, all these factors facilitate and improve the work.

The next one is 235mm in diameter, 2.26mm thick, and 36 teeth. It gives me a maximum cutting height of 70mm so I will use it when I need extra height cuts in hard wood or plywood.

The latter is 208mm in diameter, 2.65mm thick and 64 teeth, I will use it for laminated boards, MDF and melamine chipboards.

As you know, for these more delicate materials blades with more teeth are used, unlike for cutting harder materials such as wood or birch plywood.

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