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

Strengths and weaknesses of rare earth magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They have constant strength, and over nearly 10 years their attraction force decreases symbolically – ~1% (in testing),
• Neodymium magnets are distinguished by highly resistant to magnetic field loss caused by magnetic disturbances,
• By applying a shiny coating of silver, the element has an nice look,
• Neodymium magnets ensure maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for action at temperatures reaching 230°C and above...
• Possibility of accurate shaping as well as optimizing to complex applications,
• Fundamental importance in electronics industry – they are commonly used in mass storage devices, electromotive mechanisms, medical devices, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which enables their usage in small systems

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
• When exposed to high temperature, neodymium magnets suffer 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• We suggest cover - magnetic holder, due to difficulties in producing threads inside the magnet and complicated shapes.
• Health risk related to microscopic parts of magnets can be dangerous, in case of ingestion, which gains importance in the context of child safety. It is also worth noting that tiny parts of these devices can complicate diagnosis medical in case of swallowing.
• With mass production the cost of neodymium magnets is economically unviable,

Maximum lifting capacity of the magnet – what it depends on?

The specified lifting capacity represents the limit force, obtained under optimal environment, meaning:

• on a block made of structural steel, effectively closing the magnetic field
• with a thickness no less than 10 mm
• with a surface perfectly flat
• without the slightest air gap between the magnet and steel
• for force applied at a right angle (in the magnet axis)
• at ambient temperature room level

Determinants of lifting force in real conditions

In practice, the actual lifting capacity is determined by many variables, ranked from most significant:

• Distance (betwixt the magnet and the metal), as even a tiny distance (e.g. 0.5 mm) leads to a reduction in lifting capacity by up to 50% (this also applies to varnish, rust or dirt).
• Force direction – remember that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of generating force.
• Steel type – mild steel attracts best. Alloy steels lower magnetic permeability and holding force.
• Smoothness – full contact is obtained only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Temperature influence – hot environment reduces magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity was determined by applying a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, however under parallel forces the load capacity is reduced by as much as fivefold. In addition, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.