How to Extract a Stripped Screw
Stripped screws come for all of us, sooner or later. You can use several methods to remove stripped and seized screws, with a range of potential to damage the surrounding surfaces.
Start simple and reach for increasingly serious approaches as you intensify your efforts. Hopefully you'll succeed before you get all the way to the bottom of this list!
Step 1 - Apply Penetrating Oil on Metal Assemblies
When the screw is stuck through a metal surface, it’s always better to spray it beforehand with a penetrating oil or catalyst.
Step 2 - The Rubber Band Technique
If there’s a chance that it may not be too tightly set, you might want to start with the rubber band technique where a rubber band wider than the drive recess is placed between the recess and the screwdriver’s tip while applying constant pressure and turning slowly for the friction to rotate the screw to come out. A piece of scouring pad, steel wool, or a bit of friction paste might also achieve this (Figure 1).
Step 3 - Using a Manual Hand Impact Driver for Metal Assemblies
This impact tool is made super-heavy-duty and is specifically designed to receive heavy blows. The tool is usually supplied with an assortment of sturdy tempered bits (Figure 2).
3.1. Start with the first procedure in step 1.
3.2. Choose the proper bit and insert it into the impact tool.
3.3. Rotate the selector ring on the tool into the right position—counterclockwise for regular threads.
3.4. Apply another spray of penetrating oil around the screw head and on the threads if they’re apparent on the underside.
3.5. Make sure the piece from which the screw is to be extracted is sitting solidly and will not move.
3.6. Place the bit directly on the drive recess of the screw with the tool in perfect alignment with the screw.
3.7. Holding the tool firmly with one hand, drive a few heavy blows with a hammer onto the tool handle until the screw starts turning and coming out.
3.8. Once the screw starts moving, you can finish removing it using the tool as a regular screwdriver, or if it’s still too tight, you can grab it with pliers or vise grips.
Step 4 - Cleaning it Out With a Drill
Unless the drive recess is completely stripped of its edges, you can try to drill it with a smaller drill bit to clean out and even deepen the bottom of the recess to allow the screwdriver to reach deeper and get traction. The drill bit must be small enough not to further damage the perimeter of the recess. You can then try removing the screw with a new screwdriver, a new bit, or at least one that shows minimal wear.
Step 5 - Removing With a Left-Handed Drill Bit
These drill bits are very similar to regular drill bits, but on closer inspection, you can see that the spirals are wound counterclockwise as opposed to a regular drill bit. They can still drill a hole just as well as a regular bit with the drill in reverse (Figure 3).
5.1. Choose a proper-sized bit that fits inside the drive recess of the screw and insert firmly in the drill chuck.
5.2. Set the drill rotation on the reverse and put on safety eyewear.
5.3. Place the bit in the drive recess and hold the drill firmly so that everything lines up perfectly aligned with the screw.
5.4. Applying pressure on the drill, start the drill on slow speed since all you want is for the cutting edges of the bit to dig in and grab the metal at the bottom of the recess to create the necessary traction to initiate the counterclockwise rotation to rotate the screw—a drill turning too fast will just cut off those edges without gaining traction.
5.5. You can then finish removing it by grabbing the protruding head with pliers or vise grips (step 3.8).
Step 6 - Using the Double-Ended Screw Extractor Bits
These extractors are available in different sizes and offer a left-handed drill bit at one end that accommodates the extractor size at the other end, but if used carefully can easily work as in steps 5 (Figure 4).
6.1. Get the right bit for the size of the screw to be removed.
6.2. With the drill in reverse, use the end with the drill bit to make a hole inside the drive recess of the damaged screw, without going in too deep.
6.3. Turn the bit around inside the drill chuck to expose the extractor end of the bit
6.4. Place the extractor in the drilled recess and apply a steady pressure while slowly rotating the drill to retract the damaged screw.
6.5. If at this point the bit simply turns onto itself without any traction on the screw, you can drill the hole deeper but if that fails, you might have to go to the next step.
Step 7 - Straight and Spiral Fluted Extractors
Hardened steel extractors come in different designs but are all tapered with special pointed ends and are tapped into the drilled hole inside the drive recess of the screws so that it can grab a solid hold and not slip while turning counterclockwise. The spiral and the straight-fluted square extractors should be used with “T-handle or bar type tap wrench” (Figures 5 & 6), while the straight-fluted triangular extractor is much better suited to use with the more common 3-jaws drill chuck.
7.1. Select the right size fluted extractor to match the screw and a drill bit slightly larger than the extractor’s tip.
7.2. With that drill bit, bore a hole in the center of the drive recess without going too deep.
7.3. Place the tip of the extractor on the recess and tap lightly to grab the edges with the sharpened flutes.
7.4. Fastened the extractor firmly in a bar type tap wrench, and slowly start turning counterclockwise while pushing on it straight in.
7.5. As the screw starts coming out, you can then finish removing it by grabbing the protruding head with pliers or vise grips (step 3.8).
Step 8 - Extraction Using a Center Punch on Metal Assemblies
There is the basic center punch—used with a hammer— and the spring-loaded center punch. The technique is basically the same with both.
8.1. Bring the point of the center punch right up to the meeting edge of the crew head against the metal and point it in the general CCW direction of the screw.
8.2. Lean the punch slightly so that the point connects with the screw head.
8.3a. With the basic punch—give gentle taps on the punch with a hammer to turn the screw CCW.
8.3b. With the spring-loaded punch—tighten up the center punch for more tension and press firmly against the screw head until it pops off.
8.4. Keep doing this as the screw starts turning and coming until you can remove with a screwdriver or grab it with pliers to finish removing it.
Step 9 - Grinding a Slot with a Rotary Tool
If all fails, a multi-functional rotary tool can be used to grind a slot into the screw head to facilitate the removal using a blade screwdriver.