Allen screws and Allen bolts offer a lot of grip when they’re sized with the proper hex key (also referred to as a hex wrench, Allen key, or Allen wrench). But they’re also extremely easy to confuse, as they come in both metric and SAE sizes, and using the wrong size wrench for an Allen screw or bolt is a recipe for stripping, leaving us feeling hopeless and frustrated. Luckily, that bolt or screw doesn’t have to live there forever. All it takes is knowing how to remove a stripped Allen screw, and this guide will help.
How To Remove a Stripped Allen Screw: 6 Methods
Don’t panic yet. Just because that Allen bolt or screw is stripped doesn’t mean all is lost. Here are six practical ways to loosen a stripped Allen screw, most of which you can probably accomplish with basic hand tools you already own. In our opinion, it’s best to try each method in the following order:
Method 1: Try a wifferent wrench
Often, the easiest solution for removing a stuck Allen screw is to try a different Allen wrench. For example, if a metric Allen screw is stripped, try using an SAE wrench that’s just slightly larger. In some cases, there will be enough “bite” for the wrench to loosen the screw. However, if it feels like the wrench is starting to slip, stop right away.
Loosen Corrosion First: If the stripped Allen screw is also seized by rust or corrosion, apply a penetrating solvent such as Liquid Wrench, then give the screw a solid rap with a hammer and nailset. As TOH experts have advised, the shock usually loosens the screw just enough to get it moving. Just don’t place the nailset’s tip directly in the hex socket—if you damage it further, you’ll have an even tougher time getting the screw out.
Another wrench you might consider is a Torx wrench. Torx wrenches are designed for Torx screws, which have something of a star pattern with six points. Very often, these six points can nestle themselves nicely into a stripped Allen screw, providing enough purchase to loosen the screw. Beware that while the stripped screw probably won’t strip any further, the Torx tip might start to fail, so go slowly.
Pro Tip: On a TOH TV project, plumbing and heating expert Rich Trethewey and general contractor Tom Silva stressed the importance of using the right-sized tool for specialty screws like Torx fasteners. As Rich put it, “you gotta be sure you have a nice new tool that fits properly, because you do not want to strip that screw.” Tom added, “That’s the mistake most homeowners make” — using a worn or ill-fitting tool that only makes the damage worse.
Method 2: Tape, rubber glove, rubber band, or paper
While not as much of a guaranteed solution as the other methods on this list, sometimes all it takes is a bit of foreign material inside the Allen screw to back it out. You can apply a thin layer of tape around the tip of the correct size Allen wrench or a piece of a rubber glove stretched over the tip of the wrench. Then insert the Allen wrench into the stripped screw to see if you can get it to move.
If neither of those materials work, try using something slightly thickerlike a small piece of paper or a wide rubber band. Just place them over the screw head before inserting the Allen wrench and then apply pressure.
Method 3: Use a friction fluid
Friction fluid is a substance that contains small metal particles, and it acts as the opposite of a lubricant, encouraging grip rather than reducing it. A few drops of friction fluid could enhance the grip required to remove the stripped screw.
Pour a few drops of friction fluid into the screw head. Then, using the proper-size Allen wrench seated as deeply as possible (a few light taps with a hammer wouldn’t hurt), apply counter-clockwise pressure to the screw to remove it. Make sure the Allen wrench is fully seated with the friction fluid along the walls of the Allen head, not the bottom.
Method 4: Use a screw extractor
This device is typically used by drilling a hole into the top of a standard screw, then chucking the extractor into the drill and turning the extractor counter-clockwise. The extractor will bite into the screw head and start to back the screw out of the hole.
With a stripped Allen screw, you might not even need to drill into the top of the screw. Just chuck the extractor into the drill, place it in the stripped Allen hole, and turn counter-clockwise. The extractor will likely bite right away, removing the screw. If not, use the included drill bit to clean up the inside of the Allen screw before trying the extractor again.
Pro Tip: TOH master carpenter Norm Abram has noted that a screw extractor has two different tips: “The first tip is a left hand drill bit, which means it cuts when the drill is in reverse. I’ll use it to drill a small hole in the center of the screw head. Now, I’ll switch to the other tip.” This same two-step approach works well on stripped Allen screws, though you can often skip the drilling step if the hex socket still has enough material for the extractor to grab.
Method 5: Use epoxy and a screwdriver
Epoxy is an amazing substance, and you can use it to turn an Allen screw into a slotted screw, of sorts. And the process couldn’t be easier (though it might take a while).
You’ll need some epoxy mix, painter’s tape, and a flat-blade screwdriver that fits inside the Allen screw. Mix the epoxy and place a drop or two in the Allen screw. Wrap the tip of the screwdriver with a single layer of painter’s tape and place the tip in the epoxy. If there’s still excess space within the screw head, add more epoxy to fill it. Be very careful not to get epoxy on surfaces beyond the screw head, which will make it harder to remove.
Allow the epoxy to set according to the manufacturer’s instructions. Once cured, use the screwdriver to remove the Allen screw. The painter’s tape should allow you to clean the screwdriver off easily.
Method 6: Cut a slot
Another method for removing an Allen bolt or screw with a screwdriver is to cut a slot in the fastener for a flat-blade screwdriver. There are several ways to do this:
- Use an angle grinder to cut a small slot in the top of the Allen screw.
- Use a rotary tool and a grinding wheel to cut a small slot in the screw.
- Use a hacksaw to cut a thin slot in the screw.
Once the slot is cut, use a flat-blade screwdriver that’s as wide as the screw to remove the Allen screw. You might need to tap the screwdriver into the slot if you had used a hacksaw, but the process will be straightforward otherwise.
Pro Tip: Norm Abram, TOH master carpenter, cautions that a slotted bit in a drill is virtually guaranteed to slip off. When working with a newly cut slot, use a hand screwdriver rather than a power drill/driver to maintain control and avoid marring the surrounding surface.
Removing a Stripped Allen Screw Doesn’t Have to Be Hard
Sure, a stripped Allen screw can be frustrating, but it’s not the end of the world. The tips mentioned above are simple solutions for how to remove a stripped Allen screw. Work your way through these methods and, more than likely, you’ll be able to remove that Allen screw in no time.
Pro Tip: TOH master carpenter Norm Abram recommends starting with a hand screwdriver and a double dose of elbow grease: “Gently hammer the screwdriver into the head. Then use as much downward force as you can while you slowly back out the screw.”
