5 Surefire Ways to Remove Stripped Countersunk Screws

Jan 30, 2024

As if stripped screws weren't bad enough, countersunk screws are even more difficult to extract. Here's how to remove these stubborn fasteners.

Stripped screws are bad enough by themselves, but the countersunk variety adds a whole new dimension of difficulty to this ordeal. Because such fasteners sit flush with their surroundings, there's nothing left for you to grab onto. This renders pliers and other common screw extraction tools useless.

If a stripped countersunk screw has abruptly halted your repairs, don't fret: we have some nifty tips and tricks to best this seemingly impossible challenge.

While this may sound like an attempt to gaslight you, it still pays to check if you are using the right tool for the job. A hex screwdriver might fit in a Torx screw head, but it will rotate aimlessly inside the improperly matched socket. A smaller Phillips head screwdriver will also easily cam out of a larger Phillips screw head.

If you are unsure of the exact screw type you are dealing with, check your device manufacturer's support website for a service manual. That's the easiest way to correctly identify the type and size of the screw standing in your way.

Diamonds last forever, but screwdriver tips are consumables. They tend to wear out and become ineffective over time, so ensure that your screwdriver tip hasn't worn out. This is easily apparent in a regular Phillips head screwdriver, but worn hex and Torx screwdriver tips aren't as obvious. The improved grip afforded by a fresh screwdriver just might be enough to get the screw moving.

You might want to refer to our comprehensive stripped screw removal guide, if you are dealing with stubborn fasteners of the button-head or socket-head variety. The screw heads of such fasteners protrude enough to make simple removal strategies viable.

Countersunk screws, however, warrant breaking out the power tools, or employing unusual methods that go beyond simple pliers and hand tools.

A screw extractor is a special hand tool that can deal with any type of stuck fastener you throw at it. Having a set of assorted screw extractors at hand is a good idea to cover fasteners of any size. Most extractor sets come with a T-handle chuck to make the process easier.

Depending on the type of fastener and how stripped it is, you might have to drill a pilot hole into the head. The diameter of the drill bit should be smaller than that of the screw shank to prevent the screw head from being snapped off. Use a center punch to create a divot in the screw head, if you are apprehensive of the drill bit slipping off.

Extracting the fastener is a simple matter of gently tapping an appropriately sized screw extractor tool into the pilot hole, and using the T-handle chuck to twist the screw free. If it doesn't work the first time, enlarging the pilot hole and retrying with a larger extractor bit is a good idea.

Some screw extractors have left-handed drill bits at the opposite end. These bits cut when the drill is run in reverse, and make a hole that perfectly matches the attached extractor bit. An extractor set is significantly easier to use.

If you’re dealing with a particularly mangled screw, it's easy to salvage the situation by cutting a brand-new slot into the screw head. While hand tools such as a hacksaw will work on screw heads that protrude out of the screw hole, countersunk fasteners are best tackled with power tools. These include rotary cutting equipment, such as the Dremel tool.

Hardened screws are best slotted using abrasive cutting discs (pictured above) meant for metals. However, these discs only work for large countersunk screws, where the head is big enough to accommodate the cutting tool. Otherwise, you risk damaging the area around the screw head.

Rotary tools can also be used to cut slots into smaller screw heads, but you have to switch to a finer cutting accessory. Fine engraving tips (pictured below) are ideal for cutting slots into stripped fasteners too small for cutting discs.

Be sure to mask off sensitive PCBs or exposed conductors to prevent metal shavings and fragments from shorting them out, as detailed in our computer motherboard safety guide. Don't forget to wear eye protection, and blast the device clean with compressed air when you are done.

Power tools might either be overkill or unsafe for small screws. Removing such fasteners is often a simple matter of giving the screwdriver tip something substantial to grab onto. The humble rubber band is known to help in such cases.

Stretch a section of a rubber band and place it flat across the stripped screw head. The compliant material should fill the gap between the mangled screw socket and the screwdriver tip's profile. Turn the screwdriver anticlockwise to remove the stripped fastener.

If that doesn't work, replacing the rubber band with a bit of steel wool or abrasive powders, such as sand, might also do the trick. These materials provide enough grip to loosen larger screws that are stuck more firmly.

If friction hasn't worked out for you, you might want to try something more substantial (but messier) like an adhesive. Adding a dab of superglue (cyanoacrylate, or CA) to the screw head prior to inserting the screwdriver also does the trick. This won't work unless you hold steady until the CA glue has had the opportunity to fuse the tool with the screw.

More stubborn fasteners may benefit from the higher adhesion and toughness of hot glue. It's safer to dab some on the screwdriver prior to insertion, which should minimize mess on your equipment.

Regular CA and hot glues just don't cut it for stripped screws that are stuck firmly in the bosses. This job is better suited to a socket wrench, which generates enough torque to wrench loose practically anything. Although a socket wrench doesn't work on countersunk screws, there's nothing stopping you from gluing a nut onto the exposed screw head.

Two-part epoxy glues are the only viable adhesives that can withstand the tremendous torque required by this endeavor. Avoid getting epoxy glue on the rest of the equipment at all costs. Once cured, you can use a socket wrench to apply a substantially larger amount of torque on the nut glued onto the offending screw. This method should loosen the most stubborn of stripped screws.

Stripped countersunk screws are the stuff of nightmares for most makers, but these specialized tips should work on practically all fasteners irrespective of their type or severity.

However, it is smarter to prevent screws from stripping altogether by using higher-quality stainless steel fasteners, and upgrading your toolkit with precision machined hardened screwdriver bits. The former are resistant to stripping, whereas the latter minimize the risk of stripping fasteners.

Nachiket has covered diverse technology beats ranging from video games and PC hardware to smartphones and DIY over a career spanning 15 years. Some say that his DIY articles serve as an excuse to pass off his 3D printer, custom keyboard, and RC addiction as "business expenses" to the wife.