MW 6x6 / N38 - cylindrical magnet

Pros and cons of rare earth magnets.

Apart from their consistent power, neodymium magnets have these key benefits:

• They retain attractive force for almost 10 years – the drop is just ~1% (in theory),
• They are resistant to demagnetization induced by external field influence,
• Thanks to the elegant finish, the coating of nickel, gold-plated, or silver-plated gives an elegant appearance,
• The surface of neodymium magnets generates a powerful magnetic field – this is one of their assets,
• Neodymium magnets are known for strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the magnetic form),
• Thanks to the option of precise shaping and adaptation to custom needs, NdFeB magnets can be created in a broad palette of forms and dimensions, which amplifies use scope,
• Universal use in modern industrial fields – they find application in computer drives, electric motors, medical equipment, and multitasking production systems.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Disadvantages of NdFeB magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as 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
• They rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited ability of creating threads in the magnet and complicated shapes - preferred is cover - magnet mounting.
• Possible danger related to microscopic parts of magnets are risky, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that small components of these devices are able to be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Detachment force of the magnet in optimal conditions – what it depends on?

Breakaway force was determined for optimal configuration, taking into account:

• on a base made of mild steel, perfectly concentrating the magnetic flux
• whose thickness equals approx. 10 mm
• characterized by smoothness
• under conditions of gap-free contact (surface-to-surface)
• during pulling in a direction vertical to the plane
• at ambient temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

It is worth knowing that the application force may be lower depending on the following factors, in order of importance:

• Distance – existence of foreign body (rust, dirt, air) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Force direction – note that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Base massiveness – insufficiently thick plate does not close the flux, causing part of the power to be escaped into the air.
• Plate material – mild steel gives the best results. Alloy admixtures lower magnetic properties and lifting capacity.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves force. Rough surfaces reduce efficiency.
• Thermal factor – high temperature weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity was assessed using a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, however under parallel forces the holding force is lower. In addition, even a small distance {between} the magnet and the plate lowers the lifting capacity.