Like with all things, there are certain risks to be aware of when using these magnets. Firstly, size is a significant factor. Small magnets like a disc with a diameter of 6.35 millimeters and a thickness of 3.125 millimeters are harmless to your fingers. However, for children under 5 years old or any children who do not follow instructions, there's a risk of them swallowing magnets of this size. Generally, swallowing one magnet may not result in severe consequences, but swallowing more than one can cause the magnets to attract to each other and potentially clamp onto a portion of your stomach or intestines, leading to perforation and necessitating surgery.

Additionally, since most magnets are nickel-plated, a very small number of individuals might have a nickel allergy causing skin reactions.

That depends on what you're doing with them. Most electronic devices have some level of magnetic shielding inside to protect against random magnetic fields. However, if you have a MacBook Pro and you grab a 5 cm N50 cube magnet and slide it around on it, I'd say it's quite likely to damage your computer. Electronic components like speakers and microphones, as well as older floppy and hard disk drives, are particularly sensitive to magnetic forces. Generally speaking, SSD memory is not affected by magnets, but it's still best not to test it.

There are three main types of magnets: permanent magnets, temporary magnets, and electromagnets.

Permanent magnets** emit a magnetic field without needing any external magnetic or electrical source.

Temporary magnets** exhibit magnetism when attached to or near something that emits a magnetic field, but they lose that characteristic when the source of the magnetic field is removed.

Electromagnets** require an electric current to function like a magnet.Each type of magnet has its own characteristics and applications.

Several factors can impact the magnetic performance of magnets:

1. Temperature: Sintered neodymium iron boron magnets have a negative temperature coefficient (αBr < -0.13%/°C, αHcj < -0.6%/°C). Both the instantaneous highest temperature and sustained highest temperature of the operating environment can cause varying degrees of demagnetization in the magnet, including reversible and irreversible, recoverable and unrecoverable effects.

2. Humidity: Neodymium iron boron magnets are susceptible to corrosion and oxidation. While surface treatments can provide some protection, they don't fully address the impact of humidity. Drier environments generally lead to longer magnet lifetimes.How is magnetic performance measured?There are three key parameters:- Residual Induction (Br): Measured in Gauss, it indicates the magnet's ability to provide an external magnetic field.

- Coercive Force (Hc): Measured in Oersteds, it gauges the magnet's resistance to demagnetization.

- Energy Product (BHmax): Measured in Gauss-Oersteds, it quantifies the amount of energy that can be stored in the magnet.

Typically, Gauss meters, magnetometers, or pull testers are used to measure the strength of a magnet. Gauss meters measure the Gauss intensity, magnetometers measure in Gauss or arbitrary units (for easy comparison), and pull testers measure the pulling force in pounds, kilograms, or other force units.

Sintered neodymium iron boron permanent magnets are manufactured using powder metallurgy processes. The main steps include melting, powder production, forming with orientation, sintering, mechanical processing, surface treatment, and more. Among these steps, controlling the oxygen content is an important indicator of the manufacturing process's quality.

1. Material Cost: Higher performance requirements often lead to higher costs. For example, neodymium iron boron (NdFeB) magnets, such as N45 grade, are priced significantly higher than N35 grade due to their enhanced properties.

2. Processing Costs: More complex shapes generally result in higher processing costs. Tighter tolerances also increase processing costs. Additionally, smaller production batches usually lead to higher processing costs.

If stored in an environment with appropriate temperature, humidity, and without strong external magnetic fields, radiation, and other factors that can affect magnetic performance, the magnetic properties of neodymium iron boron can almost be maintained indefinitely.

There are three main parameters:

1. Residual Induction (Br): Measured in Gauss (G), it represents the remaining magnetic flux density after removing the magnetic field from a saturated state. It indicates the strength of the magnetic field that the magnet can provide externally.

2. Coercive Force (Hc): Measured in Oersteds (Oe), it refers to the external magnetic field strength required to reduce the magnet's magnetization to zero. It represents the magnet's resistance to demagnetization.

3. Energy Product (BHmax): Measured in Gauss-Oersteds (G-Oe), it quantifies the maximum amount of magnetic energy that can be stored in a unit volume of the material. It represents the magnet's ability to store energy.

When comparing magnets of the same shape and size, the surface magnetic field strength is typically ranked as follows, from highest to lowest: Neodymium Iron Boron (NdFeB) > Samarium Cobalt (SmCo) > Alnico > Ferrite > Rubber Magnet.