If you found yourself here, you likely know that Forstner bits, spade bits, and hole saws are all tools designed to drill “big holes.” But, you’re also likely struggling to figure out which of the tools is ideal for which application – and which of them you should choose for your job.
Continue reading this article to figure this out. I’ll start with the basics of the three tools – defining what they are – and continue with looking at how they differ from each other.
Going through the differences listed in the second half of this article should help you determine the winner of the “Forstner bit vs. spade bit vs. hole saw” battle when it comes to your use case.
Spade Bits, Forstner Bits & Hole Saws: The Basics
Before taking a look at how the three are different and how that affects their use, let’s start by simply looking at what defines each of the three types of drill bits.
What Is a Spade Bit?
Spade bits, also called paddle bits from time to time due to their shape, are drill bits that are meant for boring holes in wood. They are often used for rough work where speed is more important than the cleanliness of the hole produced.
When drilling all the way through a piece of wood, they tend to splinter it when they reach the other side. As such, when a cleaner finish is desired, the hole is usually drilled from both sides, meeting inside the wood piece.
Just like the two types of drill bits introduced below, spade bits are meant to make holes that are larger than those produced by regular twist drill bits. Most often, they can be found in sizes ranging from 1/4-inch all the way to 1-1/2-inch.
What Is a Forstner Bit?
Named after Benjamin Forstner who first patented the design in 1886, Forstner bits allowed woodworkers to make holes without a long “lead screw” essentially damaging the workpiece. In other words, it allowed them to drill clean, flat-bottom holes.
While the Forstner bits today are slightly different in design as they adopted a split-ring design and a “pointy tip” instead of the “lead screw.” Their purpose remains largely the same, though.
In applications where absolute accuracy and cleanliness of the drilled holes is necessary, Forstner bits are used with drill presses. That said, they can also be used with hand drills.
If you’re thinking about buying some, make sure to take a look at my Forstner bit recommendations.
What Is a Hole Saw?
Hole saws are, just like their name suggests, tools that cut holes. More specifically, they do it by rotating around their axis in a drill. As such, essentially, they are drill bits.
To be more precise, though, they consist of two parts – the saw blade which is bent into a circle and a mandrel to which the saw blade is attached. The mandrel sticks out of the saw slightly and guides the saw blade into the wood. Usually, different sized saw blades can be attached to a single mandrel.
Hole saws are available in a wide variety of sizes ranging from 1 inch all the way to a few inches.
Because of their design, they do not produce wood chips when used. Instead, they cut out a round plug. That also means they only can be used for making holes all the way through a wood piece.
If you are considering getting a set of hole saws, see my recommendations here.
Forstner Bit vs. Spade Bit vs. Hole Saw: What Are the Differences?
Now that you know what each of the different types of drill bits looks like, let’s take a look at what the differences between them are. This will also help you determine which of them is the best tool for the job you need to get done.
Cleanliness of Cut and Speed
If all you need is to drill a hole through a piece of wood – and don’t care too much about how it will look – then using a spade bit is one of your best options. It allows for boring through the thickest pieces of wood of the three and its also the fastest.
That comes at the cost of the produced hole being very rough, though. You also need to be wary of the fact that your workpiece will likely splinter where the bit exits it.
If you are looking to cut all the way through a piece of wood but are looking for a cleaner finish, then pick a hole saw. While it will take you a bit longer to cut, the finished hole will be much cleaner. Assuming you use a quality hole saw, you should also be able to avoid splintering.
That said, still drill from the “finish side” – and for the cleanest finish, sand the surface of the hole.
Finally, if you need a hole that goes only partially into the wood and doesn’t go all the way through, you should go with a Forstner bit. If used properly – and especially with a drill press – the cut will be the cleanest of the three options, and you will be able to produce a perfect flat-bottom hole.
While the above should serve as a general guide when choosing among the three, you also have to keep in mind that the size ranges that the three tools are available in differ too.
Forstner bits normally come in sizes ranging from 1/4-inch all the way to 2-1/4-inches. Commonly available spade bit sizes are 1/4-inch to 1-1/2 inches. Finally, with a diameter between 1 inch and 6 inches, hole saws are ideal if you need to make large holes.
Besides the diameter of the hole, the depth of the hole is another property in which the three differ. Spade bits generally go the deepest followed by hole saws and Forstner bits.
Spade bits and Forstner bits are exclusively woodworking tools.
On the other hand, hole saws come in a variety of types. While the most common hole saws can be only used with wood, there are also hole saws made specifically for use with metal – and even masonry.
Just as with any other product, each of the three tools is offered by a variety of brands and are of varying quality. As such, it is impossible to tell which one of them is the absolutely cheapest one and the absolutely most expensive one.
However, in general, for tools of comparable quality and size, spade bits tend to be the cheapest followed by Forstner bits and hole saws.
In most cases, sets are priced more favorably than individual pieces. You can check my overview of the best Forstner bit sets here.
If you managed to read through all of the above, congratulations – you likely know which of the three types of bits you should get. Maybe you even found out that having all three of them in your tool kit can be useful.
Now, let’s recap the above just in case you are still not sure what the differences are or which one to choose.
Starting with spade bits, they got their name from their shape. Because of the same reason, they are also called paddle bits by some people. They’re the cheapest of the three and are ideal for boring rough holes through even thick pieces of wood.
Forstner bits, on the other hand, are drill bits that are meant for making flat-bottom holes. While they can also be used for drilling through, spade bits are faster for that. Forstner bits make the cleanest holes of the three.
Finally, hole saws are different from the other two in that they cut out a solid piece of material rather than chipping it away little by little. As such, they can be fairly fast but cannot be used for partial holes. Instead, they can only be used for completely drilling through a material.
In a way, hole saws are more versatile than spade bits and Forstner bits since they come in bigger sizes and in varieties that can not only be used with wood but also metal and masonry.