In the manufacturing field, rust on Screws is a serious issue. Rust on screws poses a significant challenge, as it directly affects product quality and safety. However, by understanding the root causes and taking appropriate preventive measures, you can enhance product reliability and prevent unexpected problems. This article explains the main causes of screw rust, practical prevention methods you can apply on-site, and techniques for removing screws that have already seized due to rust—all practical know-how that engineers can put to use immediately.

3 Main Causes of Screw Rust

Rust is caused by oxidation, where metal reacts with oxygen and moisture in the air. The following three conditions accelerate the process:

1: Moisture and Water Exposure
High-humidity environments (above approx. 65%) or water droplets on screws increase the likelihood of rust. This applies not only outdoors, but also in garages on rainy days or inside toolboxes that are not properly sealed. Oxygen dissolved in water reacts with iron to form familiar red rust.

2 : Salt and Contact with Dissimilar Metals
•Salt: In coastal environments, salt absorbs moisture from the air, keeping screw surfaces damp and accelerating rust.
•Galvanic Corrosion: When metals with different potentials (e.g., iron and aluminum) come into contact, corrosion occurs. This is known as dissimilar metal corrosion or galvanic corrosion.

3 : Dust and Contaminants
Exhaust gases containing sulfur, chlorides, dust, dirt, or chlorine-based cleaners can all accelerate rusting. Maintaining a clean working environment is therefore essential.

3 Practical Ways to Prevent Screw Rust

The most effective approach combines multiple methods. Here are three easy-to-apply measures:

1. Use Anti-Rust Coatings and Lubricants
Apply a protective film on the screw surface to block moisture and oxygen. Use rust-preventive oil or lubricants: liquid type for larger surfaces, spray type for smaller parts such as bolts or bicycle chains.

2.Improve Storage Conditions
To prevent contact with dust and moisture, consider the following
•Store indoors in a dry, well-ventilated environment.
•Place desiccants (silica gel) or even old newspapers in toolboxes.

•Use airtight containers or sealed bags to protect screws from dirt and contaminants.

3. Choose Rust-Resistant Plated Screws
Selecting screws with rust-resistant finishes from the start is also effective.
•High-corrosion-resistant plating：Performs well in harsh environments.
•Cost-effective general plating：For example, trivalent white chromate plating (environmentally friendly) and widely used electro-zinc plating.

How to Remove Rusted and Seized Screws

Even with prevention, screws may still seize due to rust. Here are some solutions:

1.Combination of Hammering and Lubricant
・Tap the screw head lightly with a hammer to loosen the bond.
・Spray lubricant and allow it to penetrate for about 10 minutes.
Tap again, then carefully loosen the screw.
・Freeze-and-release sprays can shrink the metal and crack the rust, improving penetration.

2. Use Screw Extractor Tools
・Drill a hole into the screw head and insert a reverse-threaded extractor to unscrew it.

3.Cut a New Groove
If the screw head is stripped, create a new slot and use a flathead screwdriver to turn it.

4. Apply Heat
Heating the screw slightly causes expansion, which can loosen the rust bond. Be careful not to overheat, as excessive heat may deform the screw or surrounding parts.


Rust on screws can largely be prevented by understanding its causes and taking the right precautions. By following the prevention and removal methods described here, you can protect your valuable tools and products from damage. If you are unsure which method is best, want to learn more, or still struggle with rust despite proper handling, please feel free to contact us. Hanshin Neji is committed to supporting your manufacturing with safe, reliable fastening solutions.