A broken drill bit is one of those things that you don’t plan for but is bound to happen given a long enough time using a drill. Whether you’re working with wood, metal, or masonry, drill bits have a tendency to break when you push them to the limit, leaving you with an unsightly metal protrusion that needs extracting.
There are a number of ways to go about this task depending on how deeply the bit is embedded. You probably already have most of the tools needed to get the job done lying around the house, so you should be able to get started right away.
I’ll break down two different methods to remove a broken drill bit so you can complete the extraction and get back to work in no time flat.
Removing a Broken Drill Bit – Guide
If your drill bit snapped off flush with the surface then you’re going to have a more difficult time extracting it. Alternatively, if it broke off leaving enough space to fit a pair of pliers or vise grips around, then you’re in luck and should have an easier time getting it free.
If the bit broke off leaving just a small amount of real estate to fit pliers around, then you may be able to use a chisel to break some material away and free up some extra space for pliers to remove the broken drill bit. Of course, this will mar the surface of whatever you are working on so it won’t work if you need to keep the surface blemish-free.
Let’s take a look at the pliers method first as it’s a fairly straightforward way to remove a broken drill bit.
Method 1: Vise Grips
Step 1: Adjust Vise Grips
Vise grips – also referred to as locking pliers – are the ideal tool for this job as they have a locking mechanism that clamps them securely to whatever you’re working on. This lets you apply a high degree of rotational force without the pliers slipping free.
If you don’t have vise grips, then you can also use regular pliers, but you might have a harder time plying your broken bit free.
Adjust the vise grip jaws using the small adjustment screw located at the bottom of the handle. Turning the screw clockwise will tighten the jaws, and counterclockwise will loosen it.
Step 2: Clamp Pliers onto Bit
Once you’ve got the vise grips dialed in, clamp them to the protruding section of the drill bit. Turn the jaws counterclockwise to loosen the embedded drill bit.
If you’re having a hard time getting the bit to start turning, then you try applying a small amount of machine oil or lubricant to the drill bit’s flutes. Make sure not to get oil on the shank as this can make it harder for the pliers to achieve a strong grip.
Step 3: Remove the Bit
Unscrew the drill bit all the way until it’s free from your work material. Try to avoid yanking on it and pulling it free as this will only cause more damage to the material you’re working on.
Method 2: Screw Extractor
This method involves using a special screw extractor designed for removing embedded bolts and screws. While these clever little tools are built for screws, they’ll work equally well to remove a broken drill bit.
The basic idea here is you’ll flatten the top of the broken bit, drill a small hole into it using a small-diameter bit, and insert the screw extractor into it. The screw extractor can then be gripped with a pair of pliers, or a special tap wrench and rotated until the drill bit comes free.
In addition to a screw extractor, you’ll need a few additional tools and materials for this job.
Tools & Materials
- Screw extractor kit
- Tap wrench or vise grips
- Metal file
- Center punch
- Hammer and chisel
- Small diameter carbide drill bit
- Tapping fluid
Step 1: Flatten Drill Bit End
In order for the screw extractor to work effectively, you’ll need to clean up the edge of the bit and flatten it as much as possible. If it’s too jagged then you won’t be able to drill a clean hole in it or use the screw extractor effectively.
Use your hammer and chisel to break off any jagged pieces of the drill bit and then flatten it out with a metal file or an angle grinder.
Step 2: Use Center Punch to Make Divot
A center punch is basically a hardened steel tool with a sharp point for making a small hole in metal. It’s used in conjunction with a hammer to ‘punch’ a hole through tough materials.
Make sure to use a solid metal punch and not a spring-loaded one, as these likely won’t be strong enough to make a sizeable divot.
The goal here is to make a small divot in the drill bit surface to align your pilot hole with.
Step 3: Drill Pilot Hole
Next up, you’ll want to drill a pilot hole into the drill bit using a small diameter carbide or diamond drill bit. Use a bit that’s smaller than the diameter of the drill bit.
Align the drill bit with the divot you created in the previous step and drill about a 1/4″ deep. You only want to drill deep enough for the screw extractor to fit, any deeper and you risk cracking the bit in half and causing yourself even more of a headache.
Step 4: Install Screw Extractor
Once you’ve drilled your pilot hole, you’ll want to install the screw extractor. Insert the cone-shaped threaded end of the extractor into your pilot hole and hand-tighten it until you can’t turn any more, then use a wrench or pair of pliers to tighten it further.
Screw extractors have left-handed spirals rather than the right-handed spirals you find on typical crews and bolts. This means they will embed themselves deeper into the material as you rotate the tool – further increasing grip.
Screw extractors typically come in kits with several different-sized extractors. Depending on the size of your drill bit, you’ll need to match it to the right extractor size.
Step 5: Extract the Bit
Once the extractor is embedded all the way into your bit, you can begin the extraction. Use a pair of vise grips, a small wrench, or a T-handle wrench to turn the extractor in a counterclockwise motion until the bit comes free.
Tips to Prevent Broken Bits
While it’s impossible to prevent your drill bits from breaking under every circumstance, there are a few steps you can take to lessen the odds of this occurring in the future.
- Use cutting oil whenever you’re going to drill in hard materials like metal. This will keep your bit from overheating and help prevent breaking.
- Sharpen drill bits when they start to get dull instead of continuing to use them in a dulled state.
- Bring your drill up to speed slowly rather than starting to drill at high speed. This will give the bit time to start working and reduce the chances of breaking.
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