Removing a rusted screw can be a frustrating experience. Over time, screws exposed to moisture can become so corroded that a regular screwdriver just spins around uselessly when you try to loosen them. Fortunately, with the right tools and techniques, you can break through the rust and successfully extract even the most stubborn screws. Here are 3 effective methods for removing rusted screws.
Use Penetrating Oil
One of the easiest ways to loosen a seized screw is penetrating oil. The oil seeps into crevices between the screw and the threads, breaking up oxidation and corrosion. Here’s how to use it:
- Locate the rusted screw and clean any debris, grease or dirt around it. This allows for maximum oil penetration.
- Apply a penetrating oil like WD-40 or PB Blaster liberally over the screw head and threads.
- Allow the oil to soak for 10-15 minutes. This gives time for the oil to fully penetrate.
- Try unscrewing with a properly fitting screwdriver. Apply firm downward pressure as you turn.
- If needed, reapply oil and let soak again. The oil will creep further into stubborn rust with each application.
- Persist in using oil and trying to turn at intervals. The screw will slowly free up as the oil does its work.
Penetrating oils are inexpensive, readily available, and work on most lightly to moderately rusted screws. Just be patient and let the oil do its magic.
Use an Impact Driver
For screws that stubbornly resist oil and hand turning, an impact driver can provide enough power to break them free. Impact drivers have a hammering action that drives the screwdriver bit into the screw with force. Here’s how to use one:
- Clamp the screw’s material in a vise or use a helper to brace it. This prevents spinning.
- Select and insert the proper sized bit for the screw head. Make sure it’s securely retained.
- Set the impact driver to a low setting to start. High impact could damage the screw head or threads.
- Press the bit into the screw head and squeeze the driver’s trigger. Let the vibrating impacts work on freeing the screw.
- Increase the driver’s force if needed while carefully applying downward pressure.
- Stop and reapply penetrating oil if the screw remains stuck. Let it soak in for a few more minutes.
- Repeat short bursts of impacting force, working the bit out and reseating between tries.
An impact driver’s hammering force can break free even the most stubbornly seized screws after enough oil penetration. Take care not to strip the screw head.
Use a Screw Extractor
For screws so severely rusted that the head breaks off, a screw extractor is needed. Extractors bore into what remains of the screw shaft and grip to unscrew it. Here is how to use one:
- Center punch the broken screw remnant to make a starting divot for the extractor.
- Select an extractor bit slightly smaller than the screw shaft. Match the extractor to the screw type – Phillips, slotted, Torx, etc.
- Place the extractor bit into the punch divot and use an impact driver on slow setting to bore into the screw.
- Increase impact force as needed while keeping the extractor bit pressed firmly into the screw.
- Once fully seated, reverse the impact driver’s direction to back the screw out.
- If the extractor slips, reseat it and retry extraction. Applying penetrating oil may also help.
Screw extractors are a last resort but often the only way to remove a screw broken off flush or below the surface. Take care not to damage the surrounding material.
Conclusion
Rusty, stuck screws can often be removed with patience and the right techniques. Penetrating oil is excellent for freeing lightly seized screws. For stubborn ones, an impact driver’s hammering force breaks the corrosion grip. And extractors remove broken off screw shafts. Knowing how to use these methods helps solve problems with rusted fasteners. Just work deliberately and don’t force things. Before long, you’ll achieve victory over that aggravating stuck screw.
Frequently Asked Questions
What can I do if penetrating oil doesn’t work on a rusted screw?
If penetrating oil fails to loosen a stuck screw after several generous applications and waiting periods, try using an impact driver. The hammering action provides much more turning force than hand tools to break free stubborn screws.
Can I use wd40 instead of penetrant oil?
Yes, WD-40 can be used as a penetrant for rusted screws. While not as potent a penetrant asPB Blaster or similar oils, WD-40 still lubricates and seeps into rust and corrosion to help loosen stuck screws after soaking for 10-15 minutes. The key is generosity in application and time to work.
What is the best way to prevent screws from rusting?
To prevent screws from rusting and seizing up over time, apply a small amount of non-hardening threadlocker fluid or beeswax to the threads before installation. This coats the threads and protects against moisture and corrosion. Also use stainless steel or coated screws outdoors rather than plain steel.
Can I use an impact driver on plastic materials?
Avoid using an impact driver at high torque settings on screws threaded into soft plastics. The vibrating hammering action can fracture plastic threads or housings. Use hand tools only or very brief low power impact bursts if absolutely needed. Pre-drilling pilot holes also helps reduce stress.
What causes screws to become stuck or rusted in place?
Exposure to water or humidity causes screws to rust and corrode, binding them within their holes or attachments. Pooling water, rain, sprinklers, wave splash, and other wet conditions promote rust and seizing if preventative corrosion protection isn’t used on screws.
What can I do if a screw head breaks off during removal?
If the head snaps off a screw during removal attempts, stop and switch to using a screw extractor. Extractors bore into the shank portion still in the hole and back out the remnants. First center punch the shank to create a starting point for the extractor. Impact drivers help seat and turn most extractors.