How to Use a Forstner Bit: All You Need to Know

How to Use a Forstner Bit: All You Need to Know

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There are a lot of drill bits out there today. This is even true when it comes to specialized drilling jobs that require a bit to bore out a hole in materials like wood or plastic. As such, a professional craftsman or a DIYer should know their options before jumping into a project that requires hole boring.

In particular, any crafter worth their salt should know about Forstner bits. Not only that, but those same crafters should know how to use a Forstner bit in both a hand drill and a drill press.

This guide will teach you about all of that, even if you have no prior experience with this type of drill bits at all.

What Are Forstner Bits and Why Use Them?

Forstner Bit Before we go too far, let’s get you introduced to the Forstner drill bit.

To begin with, a Forstner bit is a unique type of boring drill bit that allows a woodworker to create clean, flat-bottomed holes in a workpiece.

As a result, they are often compared to spade bits and even hole saws. Forstner bits are considered to be more versatile than spade bits, though, because they can effectively bore holes at an angle or on the edge of a work piece.

In terms of their actual form, forstner bits are typified by their outer cylindrical rim, called the guide rime. These rims come in several different styles, but always allow a hole made by that bit to come out smooth and even. This rim even guides the bit at the beginning of a cut, which can be crucial when making a series of identical bores.

Above all else, woodworkers favor these bits because of their clean, reliable results when it comes to boring holes in the surface of woodwork pieces.

How to Use a Forstner Bit with a Drill Press

Now that you know what Forstner bits are, let’s take a look at how to use them. Let’s start by looking at using them with a drill press which allows for a lot of precision.

Step 1: Place Work Piece and Backing

To begin, place a piece of sacrificial wood on your drill press’ work surface. Clamp it down or secure it so that it cannot shift under pressure. Then, place your workpiece on top of the sacrificial backing (this can also be a piece of scrap wood if this is your first time using this type of bit).

This backing will prevent a blowout from occurring if you need to press your Forstner bit all the way through your workpiece to create a complete hole.

Step 2: Attach Your Bit and Adjust

With your workpiece and backing in place, you can attach your Forstner bit to your drill press.

Be sure to adjust the height of your press and the bit so that you can complete your bore to the desired depth with ease. You may also choose to come back and make more adjustments of this kind after doing a few test cuts in the next several steps.

 

Step 3: Align and Begin Drilling

Once your Forstner bit is inserted and secured, mark your workpiece to indicate the precise center of the desired hole. This can be done with a pencil or chalk.

After those marks are made, align them with the center of your Forstner bit. This can be done by lowering the arm on your drill press without activating the unit’s motor.

Once you’ve reached proper alignment, you can flip on your drill press and begin to slowly press into your workpiece. Be sure to take it slow at first so you can get a handle for the feeling of resistance caused by this kind of wide drill bit.

As you begin to establish the hole, you can increase the speed and apply more pressure via the drill press’ arm.

Step 4: Slow Down, Withdraw, and Finish

As you begin to approach your desired hole depth, begin to slow down your drill press.

Ideally, you should reach your unit’s slowest speed after reaching your target depth. Keep your Forstner bit spinning at that speed as you carefully withdraw the bit. This will create a cleaner vertical edge within the hole.

If you intend to press all the way through and create a full hole, you can continue from this point. Before doing so, be sure to clean out any excessive sawdust to prevent extra heat build-up over your Forstner bit’s blade.

How to Use a Forstner Bit with a Hand Drill

With that out of the way, let’s take a look at using a Forstner bit with a hand drill, something that can be a bit more tricky.

Step 1: Place Backing

In most cases where a hand drill must be used in conjunction with a Forstner bit, a user’s targeted surface is already “in place.” As such, it is essential to protect the backside of that surface by mounting a piece of sacrificial wood to the side opposite of where you plan to bore your Forstner bit hole.

This will prevent blowouts, especially if you intend to bore all the way to the other end of your workpiece.

Step 2: Attach Your Bit and Mark the Center

Once you’ve mounted a piece of backing into place, you can begin to prepare your hand drill for use. To do this, insert your Forstner bit into the chuck and secure it.

Once that is done, you’ll want to mark (with chalk or a pencil) the center of the circle you wish to bore in your target surface. This will allow you to align your hole more reliably once you begin to cut into that structure’s surface.

Attach the Forstner Bit

Step 3: Align Drill with Center Mark

With your intended center point marked, you should now align the center of your hand drill’s Forstner bit with the center of that mark. This should be done in a manner perpendicular to the targeted surface’s angle to prevent sloping within the hole.

To this end, you should ensure that every edge of your Forstner bit can come into contact with the wood’s surface at the same time.

Step 4: Begin Drilling and Finish

Now, firmly grasp your hand drill and gently pull the trigger to engage the Forstner bit.

Start slowly by making an initial indent that allows your bit’s guide to steady itself. You’ll also need to apply some pressure to your hand drill at this point, but not so much that your bit begins to “walk” around the wood’s surface.

Continue pressing in carefully with the trigger engaged until you reach the desired bore depth. Then, you can release the trigger and carefully slide the Forstner bit’s head out of the hole as it slows down to a stop. At this point, your hole is effectively finished.

However, if you plan to bore all the way through your workpiece, clear out any friction-causing saw dust and continue this process until popping out the other side (and into your sacrificial backing piece, ideally).

Using Forstner Bits Like a Pro: Tips & Tricks

Before you head out and try out a Forstner bit for yourself, consider these following tips and tricks for making the most of this important boring tool:

  • Keep it sharp: Forstner bits work best when they are sharp. You’ll know your bit is getting dull if it “walks” around a board’s surface excessively when you are attempting to drill with it. These bits should be replaced or sharpened to prevent excessively tearing up the exterior of your workpiece.
  • Hold it steady: Using a Forstner bit to drill a hole on a vertical surface can be challenging due to a hand drill’s weight distribution. To counteract this, you may want to add an auxiliary handle to your drill. This will give you a second support point that can keep your hole perfectly straight as it is being made.
  • Keep it cool: Forstner bits are known for heating up if they are used to make several holes in a row. As best as possible, you should avoid doing this due to the amount of friction this type of bit creates. This friction produces heat which in turn can dull your Forstner bit very quickly. If you do need to make a lot of holes in a row, consider purchasing two or three bits that you can rotate in and out of use to prevent any of them from becoming damaged way too soon.

Summary

If you’re looking to expand your boring arsenal, then a Forstner bit is a great option to try out.

As you’ve seen, this type of drill bit is exceptionally useful in a variety of hole-making situations including those that occur at angles and on the edge of a workpiece. You also now know the basics of using this kind of a bit, regardless of whether you are using a hand drill or a drill press.

If you are still undecided about which brand or model to get, make sure to also check my guide to the best Forstner bit sets.