China Neodymium And Ferrite Magnets Manufacturer & Supplier 
Magnets are a common functional material widely used in various types of motors, electronic products, medical devices, and everyday life. Many people are concerned about whether magnets will be damaged when exposed to water.
This depends on the situation. Below are some of the most common types of magnets. Let's see which one is more suitable for use in water.
Firstly, rare earth neodymium magnets are currently the strongest type of magnet material, but their biggest drawback is that they are susceptible to corrosion from water and moisture. If they are not coated or the coating is damaged, the iron base will quickly oxidize and rust, ultimately leading to a decrease in magnetic strength or even powdering.
The accompanying image shows 1 inch semi-circular rare earth neodymium magnets. An epoxy coating on the surface provides better protection.
Samarium cobalt magnets, although slightly weaker than neodymium iron boron magnets, have excellent corrosion resistance and are not easily damaged by water. They can generally be used in aquatic environments without any problems, so they are often used in military, aviation, and medical applications, and can be further protected with additional coatings.
Ceramic ferrite hard magnets are not affected by water because ferrite is mainly composed of iron oxide, which is a stable form of rust and will not be further corroded by water.
Key point: The magnetic field of a magnet originates from the arrangement of atomic magnetic moments within it. This structure does not change immediately upon contact with water. Therefore, placing a magnet in clean water for a short period of time will not cause its magnetism to disappear immediately.
Although water cannot directly demagnetize magnets, it can gradually destroy their structure through corrosion, oxidation, and other means, thereby weakening their magnetic force or even rendering them unusable. If you need to use magnets in water, you can choose based on requirements such as magnetic properties and cost.
Recommended types of magnets for underwater applications