MW 15x5 / N38 - cylindrical magnet

Pros as well as cons of rare earth magnets.

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

• They do not lose magnetism, even over around 10 years – the reduction in lifting capacity is only ~1% (based on measurements),
• They maintain their magnetic properties even under close interference source,
• Thanks to the reflective finish, the layer of Ni-Cu-Ni, gold, or silver gives an aesthetic appearance,
• Neodymium magnets generate maximum magnetic induction on a their surface, which allows for strong attraction,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Possibility of exact shaping as well as modifying to defined requirements,
• Key role in modern industrial fields – they are used in mass storage devices, brushless drives, advanced medical instruments, also complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: tips and applications.

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a strong case, which not only secures them against impacts but also raises their durability
• 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• We suggest casing - magnetic mechanism, due to difficulties in realizing threads inside the magnet and complex shapes.
• Health risk resulting from small fragments of magnets pose a threat, in case of ingestion, which gains importance in the aspect of protecting the youngest. Furthermore, tiny parts of these magnets can be problematic in diagnostics medical in case of swallowing.
• With mass production the cost of neodymium magnets can be a barrier,

Maximum magnetic pulling force – what contributes to it?

Information about lifting capacity was determined for the most favorable conditions, taking into account:

• with the contact of a yoke made of low-carbon steel, ensuring full magnetic saturation
• whose thickness is min. 10 mm
• characterized by lack of roughness
• with total lack of distance (no coatings)
• under axial application of breakaway force (90-degree angle)
• in stable room temperature

Determinants of practical lifting force of a magnet

Effective lifting capacity is influenced by working environment parameters, including (from most important):

• Clearance – existence of any layer (paint, dirt, air) interrupts the magnetic circuit, which reduces capacity steeply (even by 50% at 0.5 mm).
• Angle of force application – maximum parameter is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the plate is standardly many times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Metal type – not every steel reacts the same. Alloy additives worsen the interaction with the magnet.
• Surface quality – the more even the surface, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Thermal environment – heating the magnet results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was assessed by applying a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under parallel forces the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet’s surface and the plate reduces the lifting capacity.