UMGB 75x28 [M8+M10] GW F200 +Lina GOBLIN / N38 - goblin magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They virtually do not lose power, because even after 10 years, the performance loss is only ~1% (according to literature),
• They protect against demagnetization induced by ambient electromagnetic environments very well,
• Because of the lustrous layer of nickel, the component looks high-end,
• They exhibit extremely high levels of magnetic induction near the outer area of the magnet,
• Thanks to their exceptional temperature resistance, they can operate (depending on the shape) even at temperatures up to 230°C or more,
• The ability for precise shaping and adjustment to individual needs – neodymium magnets can be manufactured in multiple variants of geometries, which amplifies their functionality across industries,
• Significant impact in new technology industries – they find application in HDDs, electromechanical systems, medical equipment or even high-tech tools,
• Thanks to their concentrated strength, small magnets offer high magnetic performance, in miniature format,

Disadvantages of rare earth magnets:

• They may fracture when subjected to a powerful impact. If the magnets are exposed to external force, it is suggested to place them in a steel housing. The steel housing, in the form of a holder, protects the magnet from breakage , and at the same time strengthens its overall durability,
• Magnets lose pulling force when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (influenced by the magnet’s form). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Magnets exposed to moisture can degrade. Therefore, for outdoor applications, it's best to use waterproof types made of non-metallic composites,
• The use of a protective casing or external holder is recommended, since machining threads in neodymium magnets is difficult,
• Potential hazard linked to microscopic shards may arise, especially if swallowed, which is notable in the health of young users. It should also be noted that miniature parts from these devices have the potential to disrupt scanning when ingested,
• High unit cost – neodymium magnets are pricier than other types of magnets (e.g., ferrite), which can restrict large-scale applications

Breakaway strength of the magnet in ideal conditions – what contributes to it?

The given lifting capacity of the magnet represents the maximum lifting force, assessed in ideal conditions, namely:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a polished side
• in conditions of no clearance
• under perpendicular detachment force
• in normal thermal conditions

Lifting capacity in practice – influencing factors

The lifting capacity of a magnet depends on in practice key elements, according to their importance:

• Air gap between the magnet and the plate, since even a very small distance (e.g. 0.5 mm) causes a drop in lifting force of up to 50%.
• Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
• Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
• Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
• Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
• Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Lifting capacity was measured by applying a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a minimal clearance {between} the magnet and the plate lowers the lifting capacity.