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

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They have unchanged lifting capacity, and over nearly ten years their attraction force decreases symbolically – ~1% (in testing),
• They protect against demagnetization induced by surrounding magnetic fields very well,
• In other words, due to the shiny gold coating, the magnet obtains an stylish appearance,
• The outer field strength of the magnet shows remarkable magnetic properties,
• With the right combination of materials, they reach significant thermal stability, enabling operation at or above 230°C (depending on the form),
• Thanks to the freedom in shaping and the capability to adapt to unique requirements, neodymium magnets can be created in diverse shapes and sizes, which expands their functional possibilities,
• Important function in advanced technical fields – they are used in computer drives, electric motors, medical equipment or even high-tech tools,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of rare earth magnets:

• They can break when subjected to a sudden impact. If the magnets are exposed to mechanical hits, it is advisable to use in a steel housing. The steel housing, in the form of a holder, protects the magnet from breakage , and at the same time increases its overall robustness,
• Magnets lose field strength when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (influenced by the magnet’s dimensions). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Due to corrosion risk in humid conditions, it is common to use sealed magnets made of protective material for outdoor use,
• Limited ability to create internal holes in the magnet – the use of a magnetic holder is recommended,
• Potential hazard related to magnet particles may arise, in case of ingestion, which is notable in the protection of children. It should also be noted that miniature parts from these devices have the potential to interfere with diagnostics if inside the body,
• Due to the price of neodymium, their cost is relatively high,

Optimal lifting capacity of a neodymium magnet – what affects it?

The given lifting capacity of the magnet means the maximum lifting force, assessed under optimal conditions, specifically:

• with the use of low-carbon steel plate serving as a magnetic yoke
• with a thickness of minimum 10 mm
• with a refined outer layer
• with no separation
• with vertical force applied
• under standard ambient temperature

Determinants of practical lifting force of a magnet

The lifting capacity of a magnet is influenced by in practice the following factors, according to their importance:

• Air gap between the magnet and the plate, since even a very small distance (e.g. 0.5 mm) can cause 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 suitable thickness, under perpendicular forces, in contrast under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet and the plate decreases the load capacity.