Yes, a car key can absolutely get rust. The metal components, particularly the blade of a traditional mechanical key, are susceptible to rust when exposed to moisture. This is a common issue that can lead to difficulty turning the ignition, jamming in the door lock, or even breaking off inside the lock cylinder. The primary cause is prolonged contact with moisture from rain, sweat, or high-humidity environments. While modern key fobs are primarily electronic, their small metal emergency key blades are just as vulnerable.
The risk depends heavily on the key's material. Inexpensive keys are often made of simple steel, which rusts easily. Higher-quality OEM (Original Equipment Manufacturer) keys may use nickel or brass plating for added corrosion resistance. The best way to prevent rust is to keep your keys dry. Avoid leaving them in damp places like a gym bag or a porch table overnight. If your key gets wet, dry it immediately with a soft cloth.
For a key that already has minor surface rust, you can often clean it yourself. Use a very fine-grade sandpaper (like 400-grit) or a small wire brush to gently scrub the rust off. A dab of WD-40 on a cloth can help dissolve the rust and provide a protective coating, but wipe off any excess to avoid getting oil in your car's locks. If the rust is severe, pitted, or affecting the key's precise shape, do not force it into the ignition. The potential cost of extracting a broken key far outweighs the cost of getting a new one cut.
| Common Car Key Materials & Rust Susceptibility | |
|---|
| Material | Rust Resistance |
| Carbon Steel (Low-Cost Replacements) | Very Low - Highly susceptible to rust. |
| Nickel-Plated Brass | Moderate - Good protection, but can wear off. |
| Stainless Steel | High - Excellent resistance to corrosion. |
| Plastic/Rubber (Fob Housing) | Not Applicable - Can harbor moisture against metal. |
Ultimately, if you see rust, address it promptly. For modern key fobs, the greater concern is water damage to the electronics. If the fob housing is cracked, moisture can seep in and damage the circuit board, leading to a much more expensive replacement than a simple key blade.
