Circular Saw Blade For Plastic? Consider These Things Before Purchasing

circular saw blade for plastic

If you’re planning to make minor renovations around your house and have the need to cut plastic, you might wonder what’s the best way to get the job done. There are plenty of methods to cut plastic, but one of the cleanest ways is to use your circular saw. Be aware that not every blade is suitable. Therefore we will provide you a full overview of what to look out for when purchasing a circular saw blade that cuts plastic.

Selecting Circular Saw Blades For Plastic

We can use circular saw blades for cutting various kinds of plastics like PVC, plexiglass, and polycarbonate sheets. Keep a few things in mind while selecting a blade to cut plastics.

Material

Not every blade is suitable for cutting plastic. You will require a hardened steel blade. The teeth should be of tungsten carbide. This will help in making precise cuts.

Number Of Teeth

For cutting plastic, your circular blade should have a minimum of 70 teeth. As mentioned earlier, large numbers of teeth lead to a fine finish. Blades with lesser teeth are used in places where the priority is not the finishing quality, like in construction.

Coating On Blade

You must select a blade that is coated to safeguard against overheating. High heat is not ideal for cutting plastics as it may lead to the melting of the plastic sheet. We do not want molten edges.

Diameter

Before you cut plastics with circular saws, ensure the material’s maximum thickness is about 15% of the blade diameter.

Hook Angle

Hook angles can be positive or negative—positive hook angle aids in ripping. However, for cross-cutting, negative hook angles are better. This is why we prefer a negative hook angle for plastics. It gives better control and is less likely to cause chipping.

Capacity

The capacity of a saw blade determines how deep it can cut in one go. When it comes to plastics, you should select the circular saw blade that cuts the deepest. This is because plastics and plexiglass limit the circular saw’s capacity to just about 15% of the diameter.   

Precautions When You Cut Plastic With A Circular Saw

Once you choose the right blade for yourself, you might be tempted to get to work. Don’t forget to take all necessary precautions before jumping in. A few things to keep in mind are:

  1. Ensure the blade doesn’t have any bent or broken teeth.
  2. While cutting plexiglass or acrylic sheets, do not take the protective film off the sheet. 
  3. To prevent kickback, affix the plastic sheets tightly with clamps. It helps in getting clean cuts. 
  4. Do NOT stop when you cut a plastic sheet. Stopping while cutting produces excess heat, resulting in the melting of the plastic. 

Working with circular saw blades can be dangerous. It is imperative to follow these steps to carry on work smoothly.

Features Of Circular Saw Blades

Circular saws are portable versions of the traditional lumber mill saws. You use them to cut tough materials like steel, wood, ceramic tiles, etc. Let us first understand the different characteristics of a circular saw blade.

Teeth

Understandably, teeth are one of the most crucial parts of the saw blade. Generally, lesser teeth mean quicker cuts. Though, they also lead to rough cuts. 

If you want your saw to cut fast without much attention to the texture, you should choose a blade with fewer teeth. However, if you wish to get clean and precise cuts, a blade with more teeth will be better suited.

Gullet

The gullet is the space between each tooth. Gullets are judged based on their depth.

For removing large chips of wood, you require deeper gullets. Shallow gullets work better for removing finer particles from the cut. 

Expansion Slot

Expansion slots are designed for any heat caused by overheating of the machine. They prevent the blades from deformation due to heat.

Blade Size

The most commonly found circular saw blades are seven and a quarter inches. However, there are many more sizes available for different requirements. 

Circular Saw Blade Teeth

Teeth are unarguably the most crucial part of circular saw blades. Broadly, they are classified into four categories. 

Flat Top Grind Teeth (FTG)

FTGs look like small and flat chisels. They are commonly used on rip-cutting blades. These teeth create quick and clean cuts. In terms of speed, they are the most efficient blade teeth. However, this variant is most likely to cause chipping and splintering. 

They are highly durable and do not give up easily. They are also very easy to sharpen. Generally, you mount them at a high positive hook angle of about 20 degrees. They also have comparatively large gullets. 

Alternate Top Bevel Teeth (ATB)

ATBs are two different teeth that are mirror images of each other. The top of the tooth that hits the kerf is ground at an angle. This way, only a corner of the kerf is cut. The next tooth has the opposite bevel, cutting the other corner. 

These blades are designed for cross-cutting. They give smoother cuts, and there is not much of a change of splintering. ATB blades typically have a slightly negative hook angle. This does not let the blade cut too fast and helps in pulling itself through the workpiece. 

Triple-Chip Grind (TCG)

TCGs are a modified version of the standard FTG blades. They are mainly ripping blades. Since they do not have a very pointed shape, they have high durability. Despite being used on hard plastics, melamine, laminates, and tough metals, their blades are quite long-lasting.  

These blades use two types of teeth, alternating between them. One is the traditional FTG tooth, and the other is a modified FTG tooth that has its corners chamfered. The latter is often referred to as a “trapeze” tooth. 

The alternating blades make TCGs more durable as compared to FTGs. The hook angle tends to have negative values, indicating that the tooth is slanted against the cutting direction.

High-Angle Alternate Top Bevel (Hi-ATB)

Hi-ATBs are a modified version of ATBs. The basic point of difference between the two designs is the bevel angle. The bevel angle on Hi-ATB blades is significantly higher, ranging anywhere between 25 to 38 degrees. 

The hook angle is commonly zero or negatively slanted. It can fall anywhere within the -5 to 2 degrees range.

The high bevel angle increases the effect of the blade. However, it affects its durability. This high bevel angle damages the blades comparatively easily. 

The cross cuts made by Hi-ATBs are extremely smooth. These blades have somewhere between 34 to 96 teeth. They happen to be the toughest blades to sharpen. 

To Sum Up

You now have all the information you would require for selecting the perfect circular saw blade for plastic. It is essential to keep in mind the different characteristics of saw blades and their effect on our materials. Weighing your requirements against these characteristics will help in selecting the perfect blade for you.

Frequently Asked Questions (FAQs)

What is kerf?

Kerf refers to the cut’s thickness that a saw blade makes in the material as it cuts through. It is often used to describe the blade thickness as well. 

What are hook angles?

They are the amount of lean each tooth has. Hook angles may be positive or negative. It is the angle at which the tip enters the material being cut.

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