How To Sharpen A Circular Saw Blade (5 Step Guide)

Want to know how to sharpen a circular saw blade?

Super stuff, you have landed in the right place.

In this guide, I will show you:

  • 2 common sharpening methods
  • Why certain saw blades get dull before others
  • Step by step guide
  • And So Much More!
How to sharpen a circular saw blade

Before we get into the details on how to sharpen a circular saw blade, please have a read of the table below.

Quick Summary On How To Sharpen A Circular Saw Blade

I am well aware that you might not have plenty of time. I have summarized the key and critical points below for your convenience. 

  1. Sharpening a saw blade is cheaper than buying a new one
  2. There are 2 methods that are generally used. Method 1 – using a flat file. Method 2 – Grinding using the side surface of a diamond blade on a table saw.
  3. Carbide tip blades last 10 to 20 times longer than normal steel tip blade.

If you want more detail be sure to read the following sections and the step by step guide below as well.

Read More:>>> Find the best Worm Drive Circular saw for DIY needs

What You Need To Know About How To Sharpen A Circular Saw blade

In order to sharpen a circular saw blade effectively and efficiently it is important to understand how a circular saw blade actually becomes dull over time.

I will present these in the article below and will have a look at each of the 4 types of key circular saw blade types and how you can learn how to sharpen them effectively.

2 popular methods of sharpening a circular saw

There are primarily two methods when you are thinking about sharpening your saw blade that I would recommend. The first method is to simply use a flat file and slowly grind the tips of the circular saw.

The second method, requires the use of a table saw with a diamond blade where you move the tips of the blunt circular saw blade into contact with the diamond blade to sharpen them up. This method is extremely effective and the video below shows you exactly how to go about it.

4 common types of circular saw blades and how they become dull.

On all circular saw blades the only portion that actually is in contact with the material is the actual tip of the saw blade. Most circular saw blades have a body that is made entirely out of steel.

Steel is used because it is tough, will not easily break (it is not very brittle) and it is quite cost effective.

However steel tips go dull extremely quickly, hence a large majority of circular saw blades have carbide tips. I will discuss this in more detail a bit later on. For now just consider this – carbide can hold an edge for between 10 to 20 times longer overall than a steel tip blade and that is why it is so popular.

Let’s get into the different types of blades, how they are used and how they can eventually go dull.

circular saw

Ripping blade

This type of blade typically has between 24 to 30 teeth. The jagged edges are quite pronounced with very large gaps between the teeth.

The reason being this circular saw is design to specifically cut in the direction of the grain (rip cut). It should only ever be used for rip cutting because it can cause a bit of damage if used as a cross cut blade in terms of wood chips and splinters on the cutting edges.

Read More:>>> Learn the differences between Bevel cut and Miter Cut

Cross cut blade

This circular saw blade is designed to cut at a 90° degree angles of the grain and hence the name cross cut.

Because of this it provides a finer and smoother finish due to it’s 60 to 90 teeth.

Combination blade

This circular saw blade as the name suggests is a combination of the two types of blades, namely the cross cut and the ripping blade. It can perform both cross cuts and rip cuts.

However the downside of these types of blades is that they tend to not last very long and become dull quite quickly.  

Composite blade

The last blade is designed specifically to cut through man made wood such as plywood. This type of wood is very “splintery” and requires a blade with between 40 – 60 teeth to ensure a smooth and consistent finish.

Key thing to remember is if you use a saw blade in a manner that is contrary to it’s design it will lose its sharpness a lot faster.

How does carbide affect how often you need to sharpen your circular saw

carbide tip

Carbide (which is generally tungsten carbide, or titanium carbide) is a very common material that you will find on circular saws. The reason it is so popular is because it is really tough and it does not deform as much as steel when performing different types of cuts.

This carbide is typically brazed onto the steel tips of a circular saw blade. This small but extra addition of carbide ensures that your saw blade is able to hold an edge for between 10 to 20 times longer than it would have been able to without this material.

Often, and we will get into it when looking at the different steps, you will be sharpening the actual carbide tip when sharpening your circular saw blade.

Equipment You’ll need to know how to sharpen a circular saw blade

See below a list of the key critical equipment you will need depending on the method you decide upon.

For ease of simplicity I have labelled method 1 (as the simple method with a flat file) and method 2 (the method requiring table saw and diamond blade)

  • Blunt circular saws (both methods)
  • Table saw with a diamond blade (method 2)
  • Vice grip (method 1)
  • Pencil (method 1)
  • Flat file (method 1)
  • Piece of plywood (method 2)
carbide tip

5 Steps Guide On How To Sharpen A Circular Saw Blade

For method 1 

Step 1: Remove the circular saw blade from saw

In this step remove the circular saw from it’s housing in the base of the saw. Be sure to turn everything off, the saw should have no power when you are performing this exercise.

Step 2: Mark using a pencil

Take your pencil and place a mark inline with one of the circular saw blade teeth. This mark will serve as a guide for where you start filing

Step 3: Fasten tightly within a vice grip

Place your circular saw blade within a vice grip and clamp it tightly. This will ensure that it does not move as you begin to file.

Step 4: File the leading edges and tips

Starting at the position and location of your pencil mark slowly and rhythmically take you flat file and move back and forth across the leading edge of each saw tooth. Do this back and forward motion 4 or 5 times.

It is very important that as you do this, you are not applying excessive force as you do not want to damage the carbide material (if it’s there).

One key thing you can look for here is that you should be able to see the shiny part of the carbide edge after you have performed the file. Then you can be assured that you have filled through the edges correctly.

Step 5: Flip the saw blade and repeat step 4

Unscrew the vice flip the blade and continue filing the leading edges all the way around until you reach a point whereby you have completed the entire set of teeth. It’s that simple see the video below for visual walk through.

Method 2 – Using a table saw

Step 1: Safety

This method requires far more precision and safety. Please ensure that you have the items below as a minimum:

  • workman gloves,
  • ear muffs as the grinding produces a loud pitched noise,
  • Respirator this ensures that you will not be breathing in any small particles that could cause harm; and
  • Eye protection. When performing the sharpening exercise you will be chipping away small pieces of metal, if these end up in your eye it could cause terrible injuries.

Step 2: Secure saw blade above the flat surface of the table saw

Take you small piece of plywood and place it firmly on the table saw table. Place your circular saw blade onto this piece of plywood with the teeth extending.

This configuration will give you more leverage and control as you rotate and move the saw blade closer to the spinning circular saw edges.

Step 3: Power up and start sharpening

Power on the table saw so that the diamond saw blade can run and operate at full speed. Move each teeth at a bevel to the edge of the spinning diamond saw in a controlled manner.

Move the edge up and down the spinning diamond saw keeping it there for 2 or 3 seconds per teeth.

Step 4: Perform sharpen for each tooth by grinding for 2-3 seconds

Once you get the hang of it keep grinding away each tooth's leading edge slowly until you are comfortable that you have sharpened all of them fairly equally.

Step 5: Test

Take your new sharpened circular saw blade and run it through your table saw with a test cut. See how it performs. If you followed all the steps above it should be cutting just like it’s brand new.

Read More:>>> Find a top class table saw for beginners

Final Thoughts On How To Sharpen A Circular Saw Blade

Sharpening a circular saw blade is actually much cheaper than going to buy a new one from the store, by following the simple steps above it can take you 10 to 15 minutes to sharpen your blade and save you up to $30 to $40 dollars in total.

I really had fun creating this guide. I hope you enjoyed it and that it’s been helpful overall.

Mogale Modisane, PrEng

Mogale Modisane, PrEng

Mogale is a professional engineer (PrEng). With experience working on large-scale Solar, Wind, and Hybrid Projects. He has been exposed to multiple tools throughout his career and has a keen interest in breaking down the often murky world of power tools, machines, and measurement equipment making them more accessible and understandable to everyone.

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Mogale Modisane, PrEng

Mogale Modisane, PrEng

Mogale is a professional engineer (PrEng). With experience working on large-scale Solar, Wind, and Hybrid Projects. He has been exposed to multiple tools throughout his career and has a keen interest in breaking down the often murky world of power tools, machines, and measurement equipment making them more accessible and understandable to everyone.

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