What is the Arbor on a Table Saw?

May 29, 2022

Table saw arbor shaft.

If you read through a woodworking forum for the first time, you might come across some terms like the arbor of the table saw, and you might be scratching your head in utter ignorance as to what this term means. Arbor, of course, may also mean “tree branches” or “vines” in the Webster Dictionary. Yet, in woodworking, it refers to the mandrel or spindle that protrudes from the table saw assembly where the table saw blade gets mounted. It is the motor shaft driven by the motor to make the saw blade rotate.

The arbor and the saw blade were immovable and fixed in the past. So, the table got adjusted up and down to expose less or more of the saw blade. Nowadays, however, you can set the arbor higher or lower, allowing you better control of the depth of the cut.

Understanding Further the Table Saw Blade’s Arbor

As a beginner in using the table saw, it will be best to know the different parts of the table saw. The table saw blade, of course, does not just hang in the middle of the table without support. Instead, it gets connected to the saw assembly via the shaft (mandrel or spindle). 

This shaft juts out from the saw assembly, forming an arbor. It features a design allowing the mounting of the saw blade. Since the shaft gets connected to the motor, the shaft rotates the saw blade when you turn on the motor.

The table saw arbor assembly consists of the sector gear for lowering or raising the saw blade and the arbor. The arbor is usually around 5/8″ in diameter. Yet, in some high-quality and larger table saws, the arbor features a larger diameter to allow for more bearings. 

The sector gear features an arc shape that works with the worm gear connected to the adjustment wheel. This design allows for the lowering or raising of the saw blade. 

Some specialized saws have better gearing that features an adjustment mechanism to compensate for the gearing slack and reduce backlash. The motor and arbor assembly are held in position by the rear and front trunnions complemented by the yoke that joins the two trunnions.

You might be particularly interested in the trunnions because they align the saw blade with the miter slot and the rip fence. Besides, they play a critical role in absorbing vibrations originating from the saw blade and the motor. 

They transfer these vibrations to the table, and the saw base. Wider-stance trunnions offer better stability for the arbor assembly.  

Understanding the Arbor Hole

You might also get acquainted with the term arbor hole. The arbor hole refers to the center hole of the saw blade. Moreover, the shaft should fit precisely into the arbor hole of the saw blade. Besides, it is necessary to understand the close connection between the shaft and the bore. 

When buying a saw blade, it will be best to know the diameter of the shaft. In this way, the shaft and the saw blade will fit together to achieve a steady spin when cutting.

Depending on where you buy your table saw blade, you will encounter a table saw with an arbor hole in metric and English measurements. The standard arbor hole size is 5/8.” But you will also find saw blades with smaller arbor holes like the 6″ saw blade with 1/2″ arbor hole or the 3″ saw blade with 1/4″ arbor hole.

The thing about circular blades is that they utilize arbors to accomplish the desired cutting results. So, as you search for saw blades, you will discover that miter saw blades, concrete saw blades, abrasive saw blades, panel saw blades, table saw blades, and worm driver saw blades all come with an arbor hole and need an arbor to function.

The Standard and Common Arbor Hole Sizes

The arbor hole sizes, as mentioned above, vary from one saw blade to another. The standard saw blades, of course, come with 5/8″ arbor holes. Yet, as you go up the size ladder of saw blades, you will soon discover that 12” to 14” saw blades have larger-diameter arbor holes. You will find these saw blades used in industrial and commercial sites. 

Of course, if you’re a DIYer, you will mainly deal with 8” to 10” table saw blades with a standard arbor hole size of 5/8.” 

The arbor holes might have the following diameters: 1/4″ for three-inch saw blades, 1/2″ for six-inch saw blades, 5/8″ for 7-1/4″ to 10″ saw blades, and 1″ for 12″ to 16″ saw blades

You might also get confused with some saw blades that feature metric measurements. In such a case, all you got to do is convert the metric measurement to English measurement. 

Lastly, you might also find worm drive saws with arbor holes. These saws, of course, might also have diamond-shaped arbor holes for more highly generated torque.

How to Replace Bearing on the Table Saw Arbor


As a beginner in woodworking and in the use of the table saw, you might benefit from knowing the different components of the table saw, especially the saw assembly and the arbor assembly. You will more likely deal with these assemblies when installing your table saw blade. So, you need to familiarize yourself with these components. 

As mentioned above, the arbor holes come in different diameters. So, it will help to know the diameter of the saw blade’s arbor when buying a saw blade for your table saw. In this way, you can avoid purchasing a saw blade that does not fit well with your table saw.

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