UMS 16x6.5x3.5x5 / N38 - conical magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They virtually do not lose power, because even after ten years, the performance loss is only ~1% (in laboratory conditions),
• Their ability to resist magnetic interference from external fields is among the best,
• Because of the brilliant layer of nickel, the component looks visually appealing,
• They possess intense magnetic force measurable at the magnet’s surface,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• Thanks to the possibility in shaping and the capability to adapt to specific requirements, neodymium magnets can be created in various configurations, which broadens their usage potential,
• Key role in cutting-edge sectors – they serve a purpose in data storage devices, electric motors, medical equipment or even technologically developed systems,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in small dimensions, which makes them ideal in compact constructions

Disadvantages of neodymium magnets:

• They may fracture when subjected to a heavy impact. If the magnets are exposed to external force, it is advisable to use in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from fracture while also reinforces its overall durability,
• Magnets lose magnetic efficiency when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible field weakening (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 humidity can rust. Therefore, for outdoor applications, we advise waterproof types made of rubber,
• The use of a protective casing or external holder is recommended, since machining internal cuts in neodymium magnets is not feasible,
• Safety concern due to small fragments may arise, when consumed by mistake, which is crucial in the health of young users. Furthermore, minuscule fragments from these devices can hinder health screening when ingested,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

Maximum lifting capacity of the magnet – what contributes to it?

The given pulling force of the magnet means the maximum force, assessed under optimal conditions, that is:

• with the use of low-carbon steel plate acting as a magnetic yoke
• having a thickness of no less than 10 millimeters
• with a smooth surface
• in conditions of no clearance
• with vertical force applied
• at room temperature

Lifting capacity in real conditions – 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, because 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 was determined with the use of a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, whereas under parallel forces the load capacity is reduced by as much as fivefold. In addition, even a minimal clearance {between} the magnet and the plate decreases the load capacity.