UMGB 75x28 [M10x3] GW F200 PLATINIUM + Lina GOBLIN / N52 - goblin magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their immense strength, neodymium magnets offer the following advantages:

• Their strength is durable, and after approximately ten years, it drops only by ~1% (according to research),
• They show superior resistance to demagnetization from external field exposure,
• Thanks to the polished finish and silver coating, they have an visually attractive appearance,
• They possess significant magnetic force measurable at the magnet’s surface,
• These magnets tolerate extreme temperatures, often exceeding 230°C, when properly designed (in relation to form),
• The ability for accurate shaping and adjustment to individual needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which amplifies their functionality across industries,
• Wide application in advanced technical fields – they serve a purpose in data storage devices, electric drives, clinical machines along with sophisticated instruments,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are prone to breaking when subjected to a powerful impact. If the magnets are exposed to physical collisions, it is suggested to place them in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from fracture and additionally strengthens its overall robustness,
• Magnets lose pulling force when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible field weakening (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,
• Magnets exposed to wet conditions can corrode. Therefore, for outdoor applications, it's best to use waterproof types made of coated materials,
• The use of a protective casing or external holder is recommended, since machining threads in neodymium magnets is risky,
• Health risk from tiny pieces may arise, especially if swallowed, which is significant in the protection of children. Additionally, minuscule fragments from these magnets can interfere with diagnostics if inside the body,
• Due to expensive raw materials, their cost is above average,

Best holding force of the magnet in ideal parameters – what it depends on?

The given lifting capacity of the magnet corresponds to the maximum lifting force, assessed in the best circumstances, that is:

• with the use of low-carbon steel plate acting as a magnetic yoke
• with a thickness of minimum 10 mm
• with a refined outer layer
• with no separation
• in a perpendicular direction of force
• in normal thermal conditions

Practical aspects of lifting capacity – factors

The lifting capacity of a magnet is determined 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.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under shearing force the holding force is lower. In addition, even a small distance {between} the magnet’s surface and the plate decreases the load capacity.