UMGB 67x28 [M8+M10] GW F 120+ Lina GOBLIN / N38 - goblin magnetic holder

Strengths and weaknesses of neodymium magnets.

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

• They do not lose strength, even over around 10 years – the drop in power is only ~1% (theoretically),
• Neodymium magnets remain exceptionally resistant to demagnetization caused by external field sources,
• Thanks to the elegant finish, the surface of nickel, gold, or silver gives an aesthetic appearance,
• The surface of neodymium magnets generates a maximum magnetic field – this is one of their assets,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, allowing for action at temperatures approaching 230°C and above...
• Thanks to versatility in forming and the capacity to modify to unusual requirements,
• Wide application in future technologies – they find application in magnetic memories, brushless drives, medical equipment, as well as modern systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Cons of neodymium magnets: weaknesses and usage proposals

• To avoid cracks under impact, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• Neodymium magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (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
• They oxidize in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We suggest a housing - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complex shapes.
• Potential hazard to health – tiny shards of magnets pose a threat, if swallowed, which is particularly important in the context of child safety. Additionally, small components of these devices can complicate diagnosis medical in case of swallowing.
• Due to expensive raw materials, their price exceeds standard values,

Detachment force of the magnet in optimal conditions – what contributes to it?

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

• with the application of a yoke made of special test steel, guaranteeing maximum field concentration
• possessing a thickness of min. 10 mm to avoid saturation
• with an ideally smooth touching surface
• under conditions of gap-free contact (surface-to-surface)
• during pulling in a direction perpendicular to the plane
• in temp. approx. 20°C

Determinants of lifting force in real conditions

Bear in mind that the magnet holding will differ influenced by elements below, starting with the most relevant:

• Distance – existence of foreign body (paint, tape, gap) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Direction of force – highest force is reached only during pulling at a 90° angle. The force required to slide of the magnet along the plate is typically many times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin steel does not close the flux, causing part of the power to be wasted to the other side.
• Material type – the best choice is pure iron steel. Cast iron may attract less.
• Base smoothness – the more even the surface, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Thermal environment – heating the magnet results in weakening of force. Check the maximum operating temperature for a given model.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under parallel forces the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate decreases the holding force.