MPL 40x15x6 / N38 - lamellar magnet

Strengths as well as weaknesses of rare earth magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• They retain magnetic properties for almost ten years – the drop is just ~1% (according to analyses),
• Neodymium magnets are distinguished by exceptionally resistant to loss of magnetic properties caused by external field sources,
• The use of an shiny finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Magnetic induction on the top side of the magnet is very high,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Thanks to the option of precise molding and adaptation to specialized needs, NdFeB magnets can be created in a wide range of forms and dimensions, which increases their versatility,
• Fundamental importance in future technologies – they serve a role in magnetic memories, drive modules, medical devices, also technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a strong case, which not only protects them against impacts but also raises their durability
• NdFeB magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop 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 very resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore during using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Limited ability of producing threads in the magnet and complex shapes - recommended is a housing - magnet mounting.
• Potential hazard related to microscopic parts of magnets can be dangerous, in case of ingestion, which becomes key in the aspect of protecting the youngest. Additionally, small elements of these devices are able to complicate diagnosis medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum lifting capacity of the magnet – what affects it?

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

• with the use of a yoke made of low-carbon steel, guaranteeing maximum field concentration
• possessing a thickness of minimum 10 mm to avoid saturation
• with an ground touching surface
• with direct contact (no impurities)
• for force acting at a right angle (pull-off, not shear)
• at temperature approx. 20 degrees Celsius

Impact of factors on magnetic holding capacity in practice

Please note that the application force may be lower depending on elements below, in order of importance:

• Clearance – existence of any layer (paint, tape, air) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Load vector – highest force is obtained only during perpendicular pulling. The shear force of the magnet along the surface is standardly many times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Material composition – different alloys attracts identically. Alloy additives worsen the interaction with the magnet.
• Plate texture – smooth surfaces guarantee perfect abutment, which increases force. Rough surfaces reduce efficiency.
• Thermal environment – temperature increase causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity was measured using a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under shearing force the holding force is lower. Additionally, even a minimal clearance {between} the magnet and the plate lowers the load capacity.