MPL 15x5x5 / N38 - lamellar magnet

Pros as well as cons of rare earth magnets.

Besides their tremendous field intensity, neodymium magnets offer the following advantages:

• They virtually do not lose power, because even after 10 years the decline in efficiency is only ~1% (according to literature),
• They maintain their magnetic properties even under external field action,
• In other words, due to the metallic surface of nickel, the element becomes visually attractive,
• Magnetic induction on the surface of the magnet turns out to be extremely intense,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Thanks to the ability of flexible shaping and adaptation to custom projects, magnetic components can be produced in a broad palette of geometric configurations, which makes them more universal,
• Wide application in high-tech industry – they find application in hard drives, electromotive mechanisms, diagnostic systems, as well as technologically advanced constructions.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: application proposals

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a steel housing, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in producing threads and complex shapes in magnets, we recommend using a housing - magnetic holder.
• Potential hazard related to microscopic parts of magnets are risky, in case of ingestion, which gains importance in the aspect of protecting the youngest. It is also worth noting that small components of these magnets are able to be problematic in diagnostics medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

Magnetic strength at its maximum – what it depends on?

Breakaway force was defined for the most favorable conditions, including:

• using a base made of low-carbon steel, acting as a magnetic yoke
• whose transverse dimension reaches at least 10 mm
• characterized by lack of roughness
• without the slightest air gap between the magnet and steel
• for force applied at a right angle (in the magnet axis)
• in stable room temperature

Determinants of practical lifting force of a magnet

Real force is influenced by working environment parameters, mainly (from priority):

• Clearance – existence of foreign body (paint, tape, air) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is available only during perpendicular pulling. The shear force of the magnet along the surface is standardly many times smaller (approx. 1/5 of the lifting capacity).
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of generating force.
• Material composition – different alloys reacts the same. High carbon content weaken the attraction effect.
• Surface finish – ideal contact is possible only on polished steel. Rough texture create air cushions, weakening the magnet.
• Temperature – temperature increase causes a temporary drop of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity testing was carried out on a smooth plate of optimal thickness, under perpendicular forces, however under attempts to slide the magnet the load capacity is reduced by as much as 75%. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the holding force.