MW 8x8 / N38 - cylindrical magnet

Advantages as well as disadvantages of neodymium magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They have unchanged lifting capacity, and over more than ten years their attraction force decreases symbolically – ~1% (in testing),
• They feature excellent resistance to weakening of magnetic properties as a result of external fields,
• In other words, due to the reflective finish of nickel, the element gains a professional look,
• Neodymium magnets generate maximum magnetic induction on a contact point, which allows for strong attraction,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling functioning at temperatures reaching 230°C and above...
• Due to the possibility of accurate forming and adaptation to individualized requirements, neodymium magnets can be modeled in a wide range of geometric configurations, which amplifies use scope,
• Fundamental importance in innovative solutions – they serve a role in data components, electric drive systems, advanced medical instruments, and technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which makes them useful in compact constructions

Disadvantages of neodymium magnets:

• At very strong impacts they can crack, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Due to limitations in creating threads and complex forms in magnets, we recommend using a housing - magnetic mechanism.
• Potential hazard to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which becomes key in the context of child safety. Furthermore, tiny parts of these products are able to disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what it depends on?

Breakaway force was determined for the most favorable conditions, assuming:

• with the contact of a sheet made of special test steel, guaranteeing full magnetic saturation
• whose thickness is min. 10 mm
• with an ground touching surface
• with direct contact (no paint)
• under perpendicular force vector (90-degree angle)
• at temperature approx. 20 degrees Celsius

Determinants of practical lifting force of a magnet

During everyday use, the real power depends on many variables, listed from crucial:

• Clearance – existence of foreign body (rust, tape, gap) acts as an insulator, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Plate material – mild steel attracts best. Higher carbon content decrease magnetic properties and holding force.
• Plate texture – ground elements ensure maximum contact, which improves force. Uneven metal reduce efficiency.
• Thermal environment – temperature increase causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 5 times. In addition, even a small distance {between} the magnet’s surface and the plate decreases the holding force.