RM R7 SUPER - 13000 Gs / N52 - magnetic distributor

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their tremendous field intensity, neodymium magnets offer the following advantages:

• They virtually do not lose power, because even after ten years, the performance loss is only ~1% (based on calculations),
• They protect against demagnetization induced by surrounding magnetic fields remarkably well,
• The use of a mirror-like silver surface provides a eye-catching finish,
• They have very high magnetic induction on the surface of the magnet,
• Thanks to their enhanced temperature resistance, they can operate (depending on the shape) even at temperatures up to 230°C or more,
• The ability for accurate shaping and adaptation to custom needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which extends the scope of their use cases,
• Wide application in advanced technical fields – they find application in HDDs, electric motors, clinical machines as well as other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer intense magnetic field in compact dimensions, which makes them useful in compact constructions

Disadvantages of NdFeB magnets:

• They are prone to breaking when subjected to a powerful impact. If the magnets are exposed to mechanical hits, they should be placed in a metal holder. The steel housing, in the form of a holder, protects the magnet from damage and increases its overall resistance,
• High temperatures may significantly reduce the holding force of neodymium magnets. Typically, above 80°C, they experience permanent loss in performance (depending on size). To prevent this, we offer heat-resistant magnets marked [AH], capable of working up to 230°C, which makes them perfect for high-temperature use,
• Due to corrosion risk in humid conditions, it is recommended to use sealed magnets made of plastic for outdoor use,
• The use of a protective casing or external holder is recommended, since machining fine details in neodymium magnets is not feasible,
• Possible threat from tiny pieces may arise, when consumed by mistake, which is crucial in the protection of children. Additionally, minuscule fragments from these products may interfere with diagnostics after being swallowed,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

Maximum lifting force for a neodymium magnet – what affects it?

The given holding capacity of the magnet represents the highest holding force, calculated in the best circumstances, namely:

• with mild steel, serving as a magnetic flux conductor
• having a thickness of no less than 10 millimeters
• with a polished side
• in conditions of no clearance
• under perpendicular detachment force
• at room temperature

Key elements affecting lifting force

In practice, the holding capacity of a magnet is conditioned by the following aspects, from crucial to less important:

• Air gap between the magnet and the plate, because 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 assessed by applying a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 75%. Additionally, even a slight gap {between} the magnet’s surface and the plate decreases the holding force.