UMGB 75x28 [M10x3] GW F200 GOLD +Lina GOBLIN / N42 - goblin magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They have stable power, and over more than 10 years their performance decreases symbolically – ~1% (in testing),
• They are very resistant to demagnetization caused by external field interference,
• The use of a decorative gold surface provides a refined finish,
• They have very high magnetic induction on the surface of the magnet,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• Thanks to the freedom in shaping and the capability to adapt to individual requirements, neodymium magnets can be created in different geometries, which increases their functional possibilities,
• Important function in cutting-edge sectors – they are used in data storage devices, rotating machines, healthcare devices or even high-tech tools,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They may fracture when subjected to a heavy impact. If the magnets are exposed to mechanical hits, it is suggested to place them in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from breakage and additionally enhances its overall strength,
• Magnets lose power 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 damp air can degrade. Therefore, for outdoor applications, we recommend waterproof types made of rubber,
• The use of a protective casing or external holder is recommended, since machining threads in neodymium magnets is not feasible,
• Safety concern due to small fragments may arise, if ingested accidentally, which is significant in the protection of children. Moreover, small elements from these magnets have the potential to hinder health screening after being swallowed,
• Higher purchase price is an important factor to consider compared to ceramic magnets, especially in budget-sensitive applications

Maximum magnetic pulling force – what contributes to it?

The given strength of the magnet corresponds to the optimal strength, determined under optimal conditions, namely:

• with mild steel, used as a magnetic flux conductor
• with a thickness of minimum 10 mm
• with a polished side
• with zero air gap
• under perpendicular detachment force
• under standard ambient temperature

Practical aspects of lifting capacity – factors

The lifting capacity of a magnet is determined by in practice key elements, from primary to secondary:

• 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 testing was performed on a smooth plate of optimal thickness, under a perpendicular pulling force, in contrast under parallel forces the lifting capacity is smaller. Additionally, even a small distance {between} the magnet and the plate decreases the load capacity.