What is Arbor Size on A Circular Saw? Know Your Tools Better!

Last Updated On May 12, 2023

As you already know, the arbor is an important feature of a circular saw regarding the cut’s precision and accuracy. For your saw to function properly, it’s crucial to use the correct arbor measurements.

What is the arbor size on a circular saw? The size of the arbor hole varies depending on the blades’ shape and radius. However, a 5/8-inch diameter is standard for an arbor shaft.

Sometimes, it can be challenging to determine the correct arbor size, as it depends on many factors. But don’t worry! In this article, we’ve discussed everything there’s to know about arbor size and how to select the perfect one for your saw. 

What is the Use of An Arbor on a Circular Saw?

The arbor hole is a shaft at the center of the blade. It holds the saw in place and supports the blade to cut accurately. Moreover, the arbor is essential to mounting and fitting the blade. When the motor/engine runs, the arbor circulates, causing the blade to rotate smoothly. 

But for the saw to run effectively and safely, you should know the correct measurements of the arbor hole according to the shape and size of the blades so it fits.

How To Determine Arbor Size for Circular Saw? 

The arbor size depends on the type of blades and the design of the saw. Here’s a chart to help you select your arbor size-

Circular Saw Blade Size (in inches)Arbor Shaft Size (in inches)
7 ¼” to 10”5/8”
12” to 16”1”
18” to 24”2 1/2”

As we can tell from the chart, the larger the size of the blade, the larger the diameter of the arbor hole will be. However, the standard size for arbor holes is ⅝ inches. 

The arbor shaft size depends on the blade’s size, so be sure to measure your blade correctly before choosing the shaft. 

How To Mount Circular Blade Onto The Arbor 

One of the primary functions of the arbor is to hold the blade in place. Here’s how you can mount your blade onto the arbor:

Step 1 

Make sure your saw is unplugged or the power’s off to avoid accidents.

Step 2 

Find the safety blade or blade breaker on your circular saw (most circular saws have it). Switch on to lock the motor in place. 

Step 3 

Using a wrench or screwdriver, undo the arbor screw. 

Step 4 

Determine the direction in which your circular saw rotates, then find out the same for your new saw. You’ll find the directional arrows engraved on the blade. 

Step 5 

Keeping the directions of the circular saw and blade matched, mount the new blade onto the arbor shaft. 

Step 6 

After securing the blade in place correctly, tighten the screw on the arbor shaft. Next, undo the lock on the blade break.

Step 7 

Plug in the circular saw and check to see if everything’s working properly. 


1. What are the features of arbors? 

The most common features of an arbor include- longer extensions for blades and a locking function. 

2. How much do arbors cost?

Most standard arbors cost around 20 to 30 dollars, with high-end ones going well over $50.

3. What types of saws use arbors?

Most saws will have an arbor. Some common examples are- a miter saw, concrete saw, table saw, panel saw, worm drive saw, abrasive saw, etc.


The arbor shaft is a unique feature of the circular saw. Unlike regular saw blades, it isn’t easy to mount a circular blade without an arbor. So, you must select an arbor that matches the blades of the saw. Hopefully, after reading this article, you’ll better understand what is arbor size on a circular saw and can choose the perfect one yourself. Good luck!

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