You’re halfway through a repair when the screw head snaps clean off. Now you’ve got a broken bolt stuck deep in the metal, and no amount of pulling or prying gets it out. Frustrating, right? A reverse drill bit is the little hero that saves the day here. It spins backward to grab and back out stubborn, damaged fasteners without wrecking the surrounding surface.
In this guide how to use a reverse drill bit, you’ll learn exactly how to use one, from setting up your drill to freeing that stuck screw. We’ll cover the right speed, the correct pressure, and the small tricks that make extraction feel almost easy. Whether you’re rescuing a rounded-off bolt or a stripped screw in an old project, these skills come in handy again and again. Let’s get that fastener out for good.
What Is a Reverse Drill Bit?
A reverse drill bit, also called a left-hand drill bit, cuts in the opposite direction of a normal bit. Instead of spinning clockwise, it works counterclockwise—the same direction you’d turn to loosen a screw or bolt. That backward motion often grips a broken fastener and spins it right out as you drill. It’s a favorite tool for removing damaged fasteners that regular methods can’t touch.
What You’ll Need
Gather these items before you start. Keeping everything close makes the job smoother and faster:
- A variable-speed drill (or a drill press for tricky angles)
- A set of reverse drill bits in various sizes
- A screw extractor or bolt extractor set for extra-stubborn cases
- A center punch to mark your starting spot
- A hammer to tap the punch
- Cutting oil or penetrating oil
- Safety glasses
- Work gloves
- A shop vacuum or brush to clear metal shavings
- A steady clamp or vise to hold your workpiece
A quick tip: pick up a complete extraction kit if you deal with broken bolts often. Having matched bits and extractors in one case saves a ton of guesswork mid-project.
Step-by-Step Guide on How to Use a Reverse Drill Bit
Work through these steps one at a time. Rushing leads to snapped bits, so slow and steady wins here.
Step 1: Secure the Workpiece
Before anything else, lock your workpiece in place. A wobbling part makes drilling dangerous and sloppy. Clamp it firmly in a vise or use a sturdy clamp against your workbench. If the damaged fastener sits in something big like a car engine or a door frame, make sure the whole assembly won’t shift.
A stable surface lets you focus your energy on the bolt, not on holding things still. This one step prevents most beginner mistakes.
Step 2: Clean and Inspect the Broken Fastener
Take a close look at the stuck screw or bolt. Wipe away rust, grease, and debris so you can see the center clearly. If the fastener looks rusted, spray a little penetrating oil and give it ten minutes to soak in. That soak often loosens things enough to make extraction far easier.
Check whether any part of the head still sticks out. Sometimes a pair of pliers grabs it before you even need to drill. If not, you’re ready to move on.
Step 3: Mark the Center With a Punch
Accuracy starts here, so don’t skip it. Place the tip of your center punch right in the middle of the broken bolt. Tap it once or twice with a hammer to create a small dimple. This dent gives your bit a place to bite instead of wandering across the surface.
A drill bit that skates off-center can damage the threads around the fastener. That dimple keeps everything lined up. For hard metals, tap firmly to make a clear, deep mark.
Step 4: Choose the Right Bit Size
Match your reverse drill bit to the size of the fastener you’re removing. Start smaller than the bolt’s diameter—you want to drill a pilot hole into the center, not chew up the whole thing. A bit that’s too large removes too much material and can ruin the threads.
If you’re using an extraction kit, follow the sizing chart that comes with it. Each extractor pairs with a specific pilot hole size. Getting this match right is the difference between a clean pull and a bigger headache.
Step 5: Set Your Drill to Reverse
Now flip your drill into reverse mode. Look for the small switch above the trigger and set it to spin counterclockwise. This backward direction is the whole point of the tool. As the bit digs in, that motion may grab the fastener and start turning it loose on its own.
Double-check the direction before you pull the trigger. Drilling forward by accident just tightens the bolt and wastes your effort. Keep the speed low for better control.
Step 6: Drill a Pilot Hole Slowly
Line up the bit with your center punch mark and start drilling at a low speed. Apply steady, firm pressure straight down—no rocking or angling. Let the bit do the cutting instead of forcing it. Add a drop of cutting oil to keep the tip cool and reduce friction.
Watch for a lucky break: sometimes the fastener spins right out as you drill. If it does, you’re done. If not, keep the pilot hole clean and centered for the next step.
Step 7: Use a Screw Extractor if Needed
Sometimes the bit alone won’t free the fastener, and that’s normal. Now you bring in the screw extractor. Insert its tapered, threaded tip into the pilot hole you just drilled. Turn it counterclockwise with a wrench or tap handle, and its reverse threads dig deeper as they grip.
Keep turning slowly and evenly. As the extractor bites, it should twist the broken bolt out with it. Go gently—forcing it too hard can snap the extractor inside the hole, which is a tough fix.
Step 8: Clear Debris and Check the Threads
Once the fastener comes free, celebrate for a second, then clean up. Vacuum or brush away all the metal shavings around the hole. Inspect the threads to see if they survived intact. Run a matching bolt in by hand to test the fit.
If the threads look damaged, a thread-repair tool or tap can clean them up. A quick check now saves you from a loose or cross-threaded fastener later. Wipe the area with a clean rag before reassembling.
Tips for Best Results
Want to work like a pro? These insider tips make a real difference on tough jobs:
- Always drill at low speed. High RPMs generate heat that hardens the metal and dulls your bit fast. Slow, steady drilling gives the reverse motion its best shot at catching the fastener and backing it out.
- Keep the bit cool with oil. A few drops of cutting oil during drilling extend the life of your bits and make cleaner pilot holes. Dry drilling into hard steel is a quick way to burn out a bit.
- Let the reverse motion work first. Before reaching for the extractor, give the backward spin a fair chance. Many broken bolts loosen and spin out during the pilot hole stage alone.
- Don’t force the extractor. If a screw extractor snaps off inside the hole, removal becomes a real nightmare. Turn it slowly and back off the moment you feel too much resistance.
- Match your bit to the metal. Cobalt or titanium-coated bits handle hardened bolts far better than basic steel ones. Using the wrong bit on tough metal just wears it down without progress.
Frequently Asked Questions
What Is a Reverse Drill Bit Used For?
A reverse drill bit is designed to remove broken or damaged fasteners like snapped bolts and stripped screws. Because it spins counterclockwise, the same direction you’d turn to loosen a fastener, it often grabs the stuck piece and backs it out while you drill. This makes it a go-to tool for extraction jobs where a normal bit would fail. Many people keep a set in their extraction kit for exactly these moments.
How Is a Left-Hand Drill Bit Different From a Regular Bit?
A regular bit cuts as it spins clockwise, while a left-hand drill bit cuts spinning counterclockwise. That reverse direction is what helps it loosen and remove a broken bolt rather than drive it deeper. In everyday drilling, you’d never notice a difference, but for extraction the backward motion is a huge advantage. Think of it as a bit built specifically for undoing, not making, holes.
Can I Use a Reverse Drill Bit Without a Screw Extractor?
Yes, and often you won’t need the extractor at all. As you drill the pilot hole, the counterclockwise motion frequently catches the damaged fastener and spins it right out. The screw extractor is your backup for the stubborn cases that don’t budge from drilling alone. Start with the bit first, then reach for the bolt extractor only if the fastener stays put.
Is It Safe to Use a Drill Press for Bolt Extraction?
A drill press is safe and actually helpful when your workpiece can be secured on the table. It keeps the bit perfectly straight, which prevents wandering and off-center holes. That accuracy matters a lot when you’re drilling into a small broken bolt. Just clamp the piece firmly and run the press at a low speed for the best control.
How Do I Stop the Bit From Slipping Off Center?
The secret is a good center punch mark before you drill. Tap a clear dimple right in the middle of the fastener so the bit has a spot to bite into. Start at a slow speed with firm, straight-down pressure to keep it locked on target. Skipping this step is the number one reason bits skate off and damage the surrounding threads.
What Should I Do if the Extractor Breaks Inside the Hole?
First, stay calm—it happens to plenty of people. A broken extractor is hardened steel, so a standard bit won’t cut it. You’ll need a specialized carbide bit or an extractor-removal tool designed for this exact problem. If it’s a valuable part, taking it to a machine shop is often cheaper than risking more damage yourself.
Conclusion
Learning to use a reverse drill bit turns one of the most dreaded repairs into a manageable job. Remember the essentials: secure your workpiece, punch a center mark, drill slowly in reverse, and bring in a screw extractor only if you need it. With a little patience, freeing a broken bolt or stripped screw becomes second nature. If you haven’t picked up a solid set or an extraction kit yet, check out our picks above to round out your toolbox. Ready for your next fix? Browse our other DIY and tool guides for more hands-on help. Happy drilling!
