Choosing the Right Circular Saw Blade For Cutting Fiberglass! (Expert Tips)

Fiberglass is a lightweight yet strong fiber-fortified plastic that is a common material in construction sites. Due to the concentrated glass fiber amassed together, it is an uphill struggle to cut them with precision.

A circular saw is best to use for a straight cut on fiberglass. Diamond-tipped, carbide-tipped, abrasive carbide-grit, and thin kerf blades are some of the best options to cut fiberglass.

Keep scrolling if you’re curious to learn more about circular saw blades that work well for cutting fiberglass.

Circular Saw Blade For Cutting Fiberglass

Discover the Secret: Choose the Right Circular Saw Blade For Cutting Fiberglass (6 Options To You)!

A circular saw is a versatile tool that can be used to cut anything and everything. However, depending on the material, the nature and traits of the blades can differ. As fiberglass is a heavily concentrated material, you wouldn’t want to make a wrong choice of blades. Here, I listed the best blades you can use to cut fiberglass with a circular saw.

1. Diamond-Tipped Circular Saw Blade

Let me burst your bubbles first. This blade is in no way associated with the diamond gem. The term diamond is used to manifest the tough characteristics of this blade. This blade is so far ahead in the race of strength it can beat a carbide-tipped blade 50 times without bending or blunting.

Since fiberglass has a large volume concentration, this diamond blade is the best choice for cutting it via a circular saw. This blade is generally used for cutting fiberglass, melamine, cement fiber panels, and wooden panels with nails inserted.

A usual diamond-tipped blade is 6.5 to 7 inches. It would easily fit your 7 ¼ circular saw. You can sharpen them when the blades are blunted, and they can be sharpened up to 12 tips before the PCD wears off and you need to replace them. If you are searching for a reliable diamond-tipped circular saw blade. Check out this No products found..

2. Carbide Tipped Circular Saw Blade

Carbide-tipped blades are the most popular blade options for cutting metallic material via a saw. A coating of tungsten carbide is applied overheavy-duty stainless steel. These are most commonly sighted in the construction, mechanical, automobile, and metal industries.

As the fiberglass is thick and dense, the blade needs to force its way in to cut the material. Thus, the sharpness is often sacrificed to cut a piece of fiberglass. But as carbide-tipped circular saw blades retain their sharpness after a long time of use, you hardly have to worry about blunting. As the blade is hardened and tempered under a fixed temperature, it sustains for a long time.

Even if the blade gets blunt after several uses, it has the option to be re-sharpened. The edge wear of this blade is very uniform, and carbide tips are directly attached to the teeth of the saw. The best part of this blade is that you can replace a particular tooth in case it breaks or loses. If you want a burr-free cut in your fiberglass, order No products found..

3. Abrasive Carbide-Grit Blade

This type of blade is mainly tipped with tungsten carbide like a usual carbide blade, but the formulation is slightly variant from the previous one. This blade is devised for abrasive materials in particular. Fiberglass, fiber cement, tile, and brick are some of the abrasive materials these blades are formulated to cut.

These abrasive carbide-grit circular saw blades have more resistance to heat. As fiberglass is a flammable material even on high heat, this blade is a perfect synchrony for fiberglass. Also, the dense texture of the fiberglass wears a general blade off easily. But the special formulation of the blade deters blunting the best way possible.

With this abrasive carbide-grit circular saw blade, you will find no teeth to be chipped or dull. The formulation is designated to counterattack snagging. So, the cut on the fiberglass becomes more smooth and edgy. If you want an upgraded pack of blades to cut fiberglass, No products found. is the perfect option for you.

4. Thin Kerf Circular Saw Blade

By kerf, the width of the blade tooth is denoted. Thin kerf blades have a thinner width on the tooth than a regular blade. Generally, a regular circular saw blade kerf is 1/8″ to 3/16″ whereas a thin kerf blade has a tooth width of 3/32″. This difference may seem insignificant with a bare eye, but it can leave a different footprint on the material.

A thin kerf blade acts drastically in minimizing the material waste and can contribute to making less waste by 30% than a regular blade. Not only that, but a thin kerf blade can also give the material a precise finish while consuming minimum energy.

This blade can provide you with the same result with a less-powered circular saw than a regular circular saw can with high-voltage power. If you want to save energy without sacrificing the integrity of the cut, this blade will fulfill your wishes. Thin kerf blades add a sharp edge but get ready for some kickbacks too. Get the best thin kerf blade No products found..

5. Steel Alloy Circular Saw Blade

Steel alloy blades are another great option for fiberglass cutting. These blades are made from alloy steel with micro-grain carbide tips on the forehead. This steel alloy blade is renowned for cutting precise cuts with the production of minimum dust.

Fiberglass dust is not safe like wood dust and is an extreme health hazard if penetrated through the lungs or eyes. So, the blade you are using to cut the material should have this ultra feature that can produce less dust that may invade your breath. And steel alloy blades are one of the perfect blades for that.

This blade is best for cutting straight cuts but draws a limitation on cutting the corner edges. Also, be mindful not to use this blade ata cutting speed that exceeds 2000 rpm. Apart from that, this blade is capable of providing you with precise cuts within the shortest period. If you are interested in purchasing an alloy steel blade, consider No products found..

6. Polycrystalline Diamond Blade

This name might be a shock to you, but I am sure you are familiar with the term PCD blades. Well, Polycrystalline Diamond Blade or PCD is a special type of blade that has teeth tipped with Polycrystalline Diamond rather than carbide. This blade is the best for resistance to abrasion. This blade is made with a carbide base and an artificial, lab-grown diamond tipped over the carbide.

The formulation of carbide, diamond, cobalt, and other metals is so unique and meticulous that this blade has assembled its fame for durability and toughness. They are so forceful that they can cut any material with only 6-8 teeth, whereas a regular blade requires 60 or even more. If you are interested in this tough blade to cut fiberglass, take into consideration to buy the No products found..

Expert Tips To Follow

  • To cut fiberglass, use the circular saw only for a straight cut. For curve or round cuts, a hand-held jigsaw and saber saw will do a smooth job.
  • Always use two hands to hold the circular saw while cutting the fiberglass. Due to its dense nature, fiberglass has a tendency to kick back while cutting.
  • Place the supported piece of fiberglass on a secured table and clamp them to the surface. Make sure the table doesn’t collide with the surface.
  • Choose blades that are heat resistant and produce less dust. Fiberglass dust is very harmful for the body and excessive dust might put your health at risk.

Frequently Asked Questions


What precautions should you take while cutting fiberglass?

Fiberglass is basically a condensation of thin fiber glasses that comes out as dust while cutting. So, the precaution before cutting fiberglass is paramount. You need to protect your eyes, lungs, skin, and hands from such fiberglass dust.

Always wear construction gloves while working on cutting the fiberglass. Wear safety goggles to protect the eyes and if any particles somehow get inside your eyes, immediately seek medical attention. Wearing long sleeve clothes to make sure that the glass fiber can’t reach through the skin.

Why should you use a carbide blade to cut fiberglass?

Fiberglass is ten times more difficult to cut compared to wood cutting. The dense concentration can’t be penetrated through easily. So, you will need a reliable blade that can dig hard and fast through the texture of fiberglass.

Carbide-tipped blades are known for their sharpness and fastness. The kerf of a carbide-tipped blade is in perfect synchrony to breach through the dense texture. Also, as fiberglass is highly flammable under high heat, the heat-resistance mechanism comes in handy to balance the heat tension between the blade and fiberglass.

How to cut fiberglass with a circular saw?

Securely placing the fiberglass on a flat and hard surface will make your job simpler. Make sure to clean out all the debris and dust from the surface. Place only the portion of fiberglass you want to cut. If any rolls or strands are lingering, clear them first. Now, make a cutline and securely run through the blade over the fiberglass.

Final Words

As fiberglass is one of the toughest cuts to master, you should not take the material lightly, even though they are very lightweight. A correct blade will make your job ten times easier to precisely cut the fiberglass. If you don’t want to ruin your fiberglass or your circular saw by an impractical decision, make sure to use a blade suitable to cut fiberglass.


My name is Michael M. Militello, and I want to help you find the right tools and the best products for your next project! As a professional tool expert here in Houston, TX, With my vast tool experience, I can help you choose the right brand, model, and size for the job. Please feel free to contact me with any questions you may have. You can reach me here on my blog and also on Facebook, Twitter , and Pinterest. I look forward to hearing from you!

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