UMGZ 20x15x7 [M4] GZ / N38 - magnetic holder external thread

Strengths as well as weaknesses of NdFeB magnets.

Besides their tremendous strength, neodymium magnets offer the following advantages:

• Their strength is durable, and after approximately ten years it drops only by ~1% (theoretically),
• They have excellent resistance to weakening of magnetic properties due to opposing magnetic fields,
• Thanks to the shimmering finish, the plating of nickel, gold, or silver gives an visually attractive appearance,
• They show high magnetic induction at the operating surface, making them more effective,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• Thanks to the option of accurate forming and adaptation to unique needs, magnetic components can be created in a broad palette of shapes and sizes, which expands the range of possible applications,
• Fundamental importance in modern industrial fields – they serve a role in computer drives, drive modules, advanced medical instruments, also modern systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which allows their use in miniature devices

Cons of neodymium magnets and ways of using them

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a special holder, which not only secures them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• Due to limitations in realizing nuts and complicated shapes in magnets, we propose using casing - magnetic mechanism.
• Health risk to health – tiny shards of magnets pose a threat, in case of ingestion, which becomes key in the context of child safety. Furthermore, small components of these products can disrupt the diagnostic process medical when they are in the body.
• With budget limitations the cost of neodymium magnets can be a barrier,

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

The load parameter shown represents the maximum value, measured under optimal environment, specifically:

• with the application of a yoke made of special test steel, guaranteeing full magnetic saturation
• with a cross-section no less than 10 mm
• with a surface perfectly flat
• under conditions of gap-free contact (surface-to-surface)
• under vertical force vector (90-degree angle)
• at room temperature

Practical aspects of lifting capacity – factors

In practice, the actual holding force results from a number of factors, ranked from crucial:

• Distance – existence of foreign body (paint, dirt, air) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Metal type – not every steel attracts identically. Alloy additives weaken the interaction with the magnet.
• Surface finish – full contact is obtained only on polished steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Temperature – heating the magnet causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was carried out on a smooth plate of suitable thickness, under a perpendicular pulling force, in contrast under shearing force the lifting capacity is smaller. In addition, even a small distance {between} the magnet and the plate reduces the load capacity.