What is the difference between a spade bit, forstner bit & a hole saw?


Need to drill a bunch of large holes on a project you are doing around the house? What is the difference between a spade bit, forstner bit & a hole saw? Which one should you use? Which one will get the job done the fastest?

Whether you are fixing or repairing something around the house or starting out on a new hobby, drilling larger holes in wood and other materials can be an issue.

With the cost of living always on the rise, maintaining things around the house can really blow your budget if you have to call a professional.

So to save you the hard work, we’ve put together this handy guide full of lots of information about Forstner bits, Spade bits, and a hole saw so that you can tell the difference between them and know when to use which. 

First, let’s take a look at what all of these different tools are. We go over each one, and give you quick answers and get to the point.

What is a Spade Bit?

Next, let’s take a look at the Spade bit. These tools are not named after their designer, instead, they are named after the way that they look, which resembles a spade.

A spade bit is a coated, carbon steel, heat treated, flat paddle bit with a sharp center point for piloting the hole. Spade bits are used for boring larger holes typically from 0.25 – 1.50 inches quickly through wood but can cause splintering on the exit side.

Some people also choose to call these tools paddle bits due to their design. No matter what you call them, they all have one job and that is to bore holes into wood. 

Unlike Forstner bits which are often used where accuracy and perfection are important, spade bits are usually used when you need to do the job quickly rather than cleanly.

That doesn’t mean that it is impossible to get a clean finish with a spade bit, but this is only possible if you are drilling a hole through the whole of the wood.

Even then it requires you to drill through both sides of the wood to achieve a perfect finish. Just like Forstner bits, spade bits have the primary job of creating holes larger than that of regular drill bits.

Spade bits are used when you need to drill a lot of holes into wood like electrical rough in on construction jobs. So if speed is important to you then a spade bit is the one for the job. 

What is a Forstner Bit?

Let’s start with the Forstner bit. This tool was first invented in 1886 and is named after the man who invented it, Benjamin Forstner.

Forstner drill bits create smooth sided, flat bottom holes with precise depths using hand held drills and drill presses. Forstner bits are a self cleaning versatile bit that can overlap holes and drill on angles, plus create mortises and tenons with tenon cutter.

Forstner bits can be used to cut through wood, plastics, pvc, resin and other materials.

Sizes range from 1/4 inch to bits over 4 inches in diameter.

These tools are specifically made for the user to create holes within the wood without needing to use a large leading screw which could potentially damage the material that you are working on.

Instead of creating damage, the Forstner bit instead creates clean and flat holes in the wood. 

Since 1886, the Forstner bits have altered slightly but their basic purpose is still the same. Instead of having a flat end to create flat holes, the Forstner bits that you can buy today have a pointy tip due to their split ring design. Despite this, they still complete the same job.

They are most commonly used in situations where accuracy is incredibly important, and will often be paired with a drill press for the best results, but can also be used with a hand drill if speed is the priority. 

What is a Hole Saw?

Finally, before we take a look at the main differences between these different types of tools, let’s take a look at what a hole saw is. As their name suggests, hole saws are tools that cut holes, mainly into wooden materials.

A hole saw is a hollow, ring shaped hole cutter with serrated leading edge that is attached to a drill via arbor or mandrel. It has a pilot drill bit in the center for stabilizing and keeping the hole saw in place while creating holes in wood or other material by rotating in the same way that regular drill bits would.

In basic terms, they are simply drill bits, but they can create much more precise holes than regular drill bits which you can buy. 

These tools can be more precise than regular drill bits due to their design. They consist of two parts: a saw blade and a mandrel. The mandrel sticks out of the drill and directs the saw blade, allowing you to make accurate cuts.

The mandrel usually attaches to your drill and then you can simply switch the saw blade rather than having to change both every time you need a larger hole.

But there is one huge difference that makes the hole saw different from the Forstner and Spade bits and that is the fact that they can only be used to create holes if you are drilling through the entire piece of wood.

This is because they cut a round plug out of the wood rather than creating a hole in the traditional drilling sense. 

Spade Bit vs Forstner Bit vs Hole Saw, the Difference

Now that we have established exactly what these different tools are, let’s take a look at the main differences between them.

Knowing these differences is very important as it allows you to determine which tool should be used for which job.

We’ve briefly touched on these, but let’s take a deeper look. 

Sizes

One of the main differences between these different attachments is the range of sizes that you have available to you.

Depending on the job that you are doing, you will need to create a hole of a certain size in the wood, and some tools have more range when it comes to size than others. 

All of these different tools have different benefits that might make you choose them for the job at hand, but getting the size of the hole correct is incredibly important. So, the sizes available could sway the choice that you make.

The common spade bit has the smallest size range with the largest option measuring approximately 1.5 inches. Forstner bits have a slightly larger range, allowing you to create holes up to 2.25 inches in size. But, the largest range, by far, is the hole saw. 

You may also consider the depth of the hole that you need to create. As we have said, hole saws are only able to cut through the entire plank of wood so that removes them unless you want to create a complete hole.

Out of spade bits and Forstner bits, spade bits tend to go the deepest, so you should bear this in mind when deciding which tool to use. 

Price

Another important deciding factor when you are choosing between these different tools is the price. Price is an influential factor in most purchases, so let’s take a look at how this might affect the type of tool that you buy. 

It is difficult to put a definitive marker on which of these tools is the most expensive and which is the cheapest as there are lots of companies that manufacture these tools. This means that you can get these components at a huge variety of price points depending on the quality, brand, and build that you want. 

That being said, there does appear to be a pattern in the market when it comes to these tools. Generally, if you compared these tools if they were produced at the same quality by the same brand, then spade bits tend to be the cheapest option.

Followed by Forstner bits, and finally hole saws. So you should remember this if the price is an important factor in the type of tool that you choose to use. 

Workpiece Materials 

Something else that will impact the type of tool that you should use is the materials that you are working with, also known as the workplace materials.

All of these tools are designed for specific purposes, so the material that you are wanting to drill into will have an impact on which will be the most effective to do the job. 

If you are working with wood, then any of these tools will be able to do the job excellently.

However, Forstner bits and spade bits are designed solely for use with wood, so if you are working with any other type of material then they will not be appropriate. 

Traditionally, hole saws were designed solely for woodworking purposes too, and some of these tools are still only compatible with wood.

However, some hole saws have been designed for use with masonry and metal too, so this is important to consider when you are choosing which type of tool to use. 

Speed and Clean Cut

Finally, you need to consider the speed at which you want to cut the hole, and how clean a finish you want from the tool.

We briefly touched on how these different tools perform earlier, so let’s take a deeper look at which can get the job done most efficiently. 

It is impossible to remove the speed and efficiency of the cut from the sharpness of the cut as they are directly linked. In terms of speed, the spade bit is by far the quickest and most efficient at cutting through wood, but it does this at a cost.

That cost is that the spade bit creates a messy hole which is fine for some jobs but not appropriate for others. 

If you want to cut through the entire plank of wood but need a cleaner finish then the hole saw would be the best tool. It is slower than a spade bit, but it has a very polished finish with little splintering.

Finally, the cleanest cut will come from the Forstner bit, but this tool isn’t that appropriate for cutting through entire planks of wood. So you have to consider the type of job that you want to do when choosing a tool depending on speed. 

Summary 

In conclusion, the Forstner bit, spade bit, and hole saw are all excellent tools for cutting holes in wood.

They all do a very similar job so deciding which is the best for you will depend on the hole that you need to cut and the factors we have looked at above. 

Dean Luoma

As a long-time homeowner, Dean has been working on his own home projects for over 30 years. He is a licensed real estate agent in the state of Minnesota, helping clients with the buying and selling of their homes.

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