MPL 20x10x5 / N38 - lamellar magnet

Strengths as well as weaknesses of neodymium magnets.

Besides their remarkable magnetic power, neodymium magnets offer the following advantages:

• Their magnetic field is durable, and after around 10 years it decreases only by ~1% (theoretically),
• Neodymium magnets are characterized by exceptionally resistant to magnetic field loss caused by magnetic disturbances,
• A magnet with a metallic gold surface has better aesthetics,
• Neodymium magnets generate maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• In view of the possibility of free molding and customization to custom projects, NdFeB magnets can be produced in a variety of shapes and sizes, which increases their versatility,
• Huge importance in modern industrial fields – they are used in data components, electric motors, advanced medical instruments, also technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which enables their usage in small systems

Disadvantages of neodymium magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only protects the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their power 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 advise using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
• Limited possibility of making nuts in the magnet and complicated forms - recommended is casing - mounting mechanism.
• Possible danger resulting from small fragments of magnets can be dangerous, in case of ingestion, which is particularly important in the context of child safety. Furthermore, small elements of these products are able to complicate diagnosis medical when they are in the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which can limit application in large quantities

Breakaway strength of the magnet in ideal conditions – what affects it?

Holding force of 5.58 kg is a measurement result performed under the following configuration:

• using a base made of mild steel, functioning as a magnetic yoke
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with an polished contact surface
• with zero gap (no impurities)
• for force acting at a right angle (in the magnet axis)
• in neutral thermal conditions

What influences lifting capacity in practice

In practice, the real power is determined by several key aspects, presented from the most important:

• Gap between magnet and steel – every millimeter of distance (caused e.g. by veneer or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is reached only during perpendicular pulling. The shear force of the magnet along the surface is usually many times smaller (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin steel causes magnetic saturation, causing part of the power to be lost to the other side.
• Material composition – not every steel reacts the same. Alloy additives worsen the interaction with the magnet.
• Surface condition – ground elements guarantee perfect abutment, which increases force. Rough surfaces reduce efficiency.
• Temperature – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under perpendicular forces, whereas under parallel forces the load capacity is reduced by as much as 75%. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the holding force.