You can remove most hex screws without a hex screwdriver by using a flat-head screwdriver that fits snugly across two opposing flats of the hex socket, a Torx bit that wedges into the hex recess, or even a pair of pliers if the screw head is exposed. The right method depends on whether you’re dealing with a hex socket (recessed) or a hex bolt head (external), and whether the fastener is stuck or just needs a basic turn.
Flat-Head Screwdriver Method
This is the quickest option for hex socket screws (the kind with a six-sided hole in the top). Choose a flat-head screwdriver with a blade width that spans from one flat wall of the hex to the opposite wall. The blade should sit firmly against two parallel inner surfaces. Press down hard while turning to keep the blade from slipping out. This works best on larger hex sizes, roughly 4 mm and above, where a standard screwdriver tip can make solid contact. On very small hex sockets, the blade tends to cam out and round the edges, so try another method first.
Using a Torx Bit as a Substitute
Torx bits (the star-shaped ones) can substitute for hex keys because their six-pointed profile wedges into a six-sided hex socket surprisingly well. The fit isn’t perfect, but it’s close enough for light to moderate torque. Common conversions that work reliably:
- T10 fits a 7/64″ hex
- T15 fits a 1/8″ hex
- T20 fits a 5/32″ hex
- T25 fits a 3/16″ (or 4.5 mm) hex
- T30 fits a 7/32″ or 1/4″ hex
- T40 fits a 9/32″ hex
Push the Torx bit firmly into the hex socket before turning. If it feels loose, try tapping it in with a light hammer strike. The star points grip the hex walls at their tips, so downward pressure matters more than with a proper hex key. Avoid this on fasteners that need heavy torque, since the point contact can strip both the Torx bit and the hex socket if you force it.
Pliers and Vise-Grips for External Hex Heads
If the screw has an external hex head (like a bolt head), locking pliers (Vise-Grips) are your best bet. Clamp them tightly onto the hex flats and turn. Regular pliers work too, but they’re more likely to slip and round the corners. The key is to grip across two parallel flats rather than across the corners. Rounding the corners makes every subsequent attempt harder, so get the grip right on the first try.
For screws recessed in a countersunk hole where pliers can’t reach, this method won’t help. Move on to one of the other approaches below.
Melting a Plastic Pen Into the Socket
For very low-torque hex screws, like those holding electronics enclosures or battery covers, you can melt the end of a plastic ballpoint pen barrel into the hex socket. Heat the pen tip with a lighter until the plastic softens, press it firmly into the hex recess, and hold it still for 30 to 60 seconds while the plastic hardens. Once set, the plastic conforms to the hex shape and gives you enough grip to turn the screw. This only works on screws that aren’t tight. Anything requiring real force will just shear the plastic.
Breaking Thread-Locking Compound With Heat
If the hex screw won’t budge regardless of your tool, it may be secured with thread-locking adhesive. Standard thread lockers break down at around 325°F, while high-temperature formulas need about 500°F. A heat gun or a small butane torch aimed at the screw head for 30 to 60 seconds usually does the job. Once heated, try turning the screw immediately while the adhesive is still softened. Let it cool and it re-hardens.
Keep the heat focused on the metal fastener, not the surrounding material. On plastic housings, this obviously isn’t an option. On wood, keep a damp rag nearby and work quickly.
Epoxying a Nut to a Stripped Hex Head
When the hex socket is stripped to the point where no tool can grip it, you can bond a nut to the top of the screw head with metal epoxy. Clean both surfaces with rubbing alcohol, apply the epoxy to the nut, press it centered onto the screw head, and leave it overnight. A product like JB Weld creates a bond strong enough that you can turn the screw with a standard wrench the next day. The bond is often stronger than the thread resistance, so the screw turns freely without breaking the epoxy joint.
This method requires patience (a full overnight cure, not just the initial set time) but it’s one of the most reliable options for badly damaged fasteners. Quick-setting super glue is too brittle for this. Use a two-part metal epoxy for the shear strength you need.
Cutting a Slot for a Flat-Head Screwdriver
If you have a rotary tool (like a Dremel) or a thin hacksaw blade, you can cut a straight slot across the top of the hex screw head. This turns it into a standard slotted screw that any flat-head screwdriver can remove. The slot needs to be deep enough for the screwdriver blade to seat firmly, usually about 1 to 2 mm depending on the screw size. Wear safety glasses when cutting into metal, since small shards and sparks fly unpredictably.
This is a destructive method. You’ll need a replacement screw afterward. But for a stuck or stripped hex screw that nothing else will turn, it’s fast and effective.
Screw Extractor Bits for Seized Fasteners
Dedicated screw extractor sets are designed for exactly this situation. They work in two steps: first you drill a small pilot hole into the center of the screw head using a left-hand drill bit, then you insert the extractor bit, which has reverse-threaded spiral flutes. As you turn it counterclockwise, the extractor digs deeper into the hole and grips tighter, pulling the screw out. Many extractors are sold in kits covering a range of screw sizes.
Extractors handle seized, rusted, and heavily stripped screws that no workaround tool can grip. The tradeoff is that you need a drill, and if the screw is made of very hard steel, you may need cobalt or carbide drill bits to get through it. For a one-time fix, a basic extractor set costs under $20 and is worth having in a toolbox.
Choosing the Right Approach
Your best method depends on two things: how tight the screw is and whether the hex socket is still intact. For a screw that’s only finger-tight or lightly secured, the flat-head screwdriver, Torx bit, or melted pen trick will work fine. For a moderately tight screw with an intact socket, the Torx substitution or pliers (on external heads) give enough torque. For stripped, seized, or thread-locked screws, jump straight to heat, epoxy, slot cutting, or a screw extractor. Trying gentle methods on a badly stuck screw just damages the socket further and makes extraction harder with each failed attempt.