MPL 5x5x1 / N38 - lamellar magnet

Advantages and disadvantages of neodymium magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They do not lose strength, even during around 10 years – the decrease in power is only ~1% (according to tests),
• They are noted for resistance to demagnetization induced by external field influence,
• Thanks to the smooth finish, the plating of Ni-Cu-Ni, gold-plated, or silver gives an elegant appearance,
• Neodymium magnets deliver maximum magnetic induction on a contact point, which ensures high operational effectiveness,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling functioning at temperatures approaching 230°C and above...
• Due to the option of free forming and customization to specialized solutions, magnetic components can be modeled in a variety of forms and dimensions, which makes them more universal,
• Fundamental importance in electronics industry – they are used in hard drives, brushless drives, medical devices, and technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets: tips and applications.

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a strong case, which not only secures them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets suffer a drop in strength. 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
• They rust in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic holder, due to difficulties in producing threads inside the magnet and complex shapes.
• Health risk related to microscopic parts of magnets pose a threat, in case of ingestion, which becomes key in the context of child health protection. Furthermore, small elements of these magnets can complicate diagnosis medical in case of swallowing.
• With mass production the cost of neodymium magnets is economically unviable,

Magnetic strength at its maximum – what contributes to it?

The declared magnet strength refers to the limit force, obtained under optimal environment, meaning:

• with the use of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• whose thickness equals approx. 10 mm
• with a plane perfectly flat
• without the slightest clearance between the magnet and steel
• for force acting at a right angle (in the magnet axis)
• at ambient temperature room level

Determinants of lifting force in real conditions

In practice, the actual holding force results from many variables, listed from crucial:

• Distance – the presence of foreign body (paint, dirt, gap) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Angle of force application – highest force is obtained only during pulling at a 90° angle. The force required to slide of the magnet along the surface is typically many times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin steel does not close the flux, causing part of the power to be wasted to the other side.
• Steel type – mild steel gives the best results. Alloy admixtures decrease magnetic permeability and holding force.
• Surface structure – the smoother and more polished the surface, the larger the contact zone and stronger the hold. Unevenness creates an air distance.
• Thermal factor – high temperature weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity was determined using a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under shearing force the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate lowers the lifting capacity.