How to Loosen a Rusted Screw (Trade-Proven Methods That Work)

Why Screws Rust in the First Place

Rust forms when steel is exposed to moisture and oxygen over time. This is especially common in:

• Outdoor fixings
• Damp or poorly
• Ventilated areas
• Older buildings
• Coastal locations

Once rust sets in, it bonds the screw to the surrounding material, making it difficult to turn.

Using the right technique early can save snapped heads and wasted time.

Tools That Make the Job Easier

Before you start, make sure you’ve got the basics to hand:

• Correct size screwdriver or bit (tight fit is key)
• Penetrating oil
• Hammer
• Pliers or grips
• Heat gun or small blowtorch (if safe to use)

Using the wrong driver or rushing this step is how screw heads get stripped.

Step-by-Step: How to Loosen a Rusted Screw

1. Apply Penetrating Oil
Spray the screw head and threads generously. Leave it for 15–20 minutes to soak in.
For badly seized screws, leaving it longer can help.

This is often enough on its own.

2. Tap the Screw Head
Lightly tap the screw head with a hammer.
This helps break the rust bond and lets the oil work deeper.

Don’t hit it hard. Controlled taps are all you need.

3. Use Steady, Controlled Pressure
Use a well-fitting driver and apply firm, even pressure.
If it doesn’t move, try gently tightening the screw first, then loosening it.

That small movement can break the rust grip.

4. Add Heat (If Safe)
If oil alone doesn’t work, apply controlled heat to the screw:

• Use a heat gun or blowtorch
• Heat the screw, not the surrounding material
• Let it cool slightly, then try again

Heat causes the metal to expand and contract, helping to break the rust bond.

⚠️ Avoid heat near plastics, finished surfaces or flammable materials.

Handy Alternatives (When You’re Stuck)

If you’re short on supplies, these can help on light rust:

• Vinegar (acid helps break rust)
• Cola (contains phosphoric acid)
• Baking soda paste

These aren’t trade-grade solutions, but they can work in a pinch.

How to Prevent Rusted Screws in Future

Prevention saves time on the next job:

• Use stainless steel or coated screws where possible
• Avoid mixing metals
• Store fixings in dry conditions
• Use exterior-rated screws outdoors
• Apply a light oil to exposed fixings

Choosing the right fixing upfront reduces failures later.

When to Stop and Rethink

If a screw won’t move after several attempts:

• Don’t force it
• Avoid snapping the head
• Consider drilling it out or replacing the fixing

On structural or critical fixings, stopping early can prevent costly damage.