MP 16x12x2 / N38 - ring magnet

Pros as well as cons of rare earth magnets.

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

• Their strength is maintained, and after around 10 years it decreases only by ~1% (theoretically),
• They are extremely resistant to demagnetization induced by external field influence,
• In other words, due to the smooth finish of nickel, the element is aesthetically pleasing,
• The surface of neodymium magnets generates a concentrated magnetic field – this is a distinguishing feature,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of detailed modeling as well as adjusting to defined needs,
• Universal use in modern technologies – they find application in hard drives, brushless drives, diagnostic systems, also technologically advanced constructions.
• Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a strong case, which not only secures them against impacts but also increases their durability
• Neodymium magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening 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 very 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, in case of application outdoors
• We recommend cover - magnetic mount, due to difficulties in creating threads inside the magnet and complicated forms.
• Possible danger resulting from small fragments of magnets pose a threat, in case of ingestion, which gains importance in the context of child safety. It is also worth noting that small components of these devices can complicate diagnosis medical when they are in the body.
• With mass production the cost of neodymium magnets is economically unviable,

Maximum magnetic pulling force – what affects it?

Breakaway force was determined for optimal configuration, assuming:

• with the application of a yoke made of low-carbon steel, ensuring full magnetic saturation
• whose transverse dimension is min. 10 mm
• characterized by even structure
• without any air gap between the magnet and steel
• under axial force direction (90-degree angle)
• in neutral thermal conditions

Practical lifting capacity: influencing factors

Real force is affected by specific conditions, mainly (from most important):

• Gap between magnet and steel – every millimeter of distance (caused e.g. by varnish or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Load vector – maximum parameter is reached only during pulling at a 90° angle. The shear force of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin steel causes magnetic saturation, causing part of the flux to be lost to the other side.
• Plate material – low-carbon steel attracts best. Higher carbon content reduce magnetic permeability and holding force.
• Surface condition – ground elements 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 testing was carried out on plates with a smooth surface of optimal thickness, under perpendicular forces, however under parallel forces the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate decreases the load capacity.