LM TLN - 20 R / N38 - magnetic leviton

Pros as well as cons of rare earth magnets.

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

• They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (based on calculations),
• Neodymium magnets remain highly resistant to demagnetization caused by external interference,
• By using a reflective coating of gold, the element presents an modern look,
• Magnetic induction on the top side of the magnet is strong,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Thanks to versatility in constructing and the ability to adapt to specific needs,
• Universal use in advanced technology sectors – they are used in data components, motor assemblies, medical equipment, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer high power in compact dimensions, which allows their use in compact constructions

What to avoid - cons of neodymium magnets: application proposals

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing 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 experience a drop in power. Often, when the temperature exceeds 80°C, their power 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 - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited ability of making threads in the magnet and complicated forms - preferred is casing - mounting mechanism.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child safety. It is also worth noting that tiny parts of these devices are able to complicate diagnosis medical in case of swallowing.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Maximum lifting force for a neodymium magnet – what contributes to it?

The declared magnet strength concerns the maximum value, obtained under laboratory conditions, namely:

• using a plate made of mild steel, functioning as a ideal flux conductor
• with a thickness minimum 10 mm
• characterized by even structure
• under conditions of gap-free contact (metal-to-metal)
• during detachment in a direction vertical to the plane
• in neutral thermal conditions

Determinants of practical lifting force of a magnet

In practice, the actual holding force is determined by a number of factors, presented from most significant:

• Air gap (betwixt the magnet and the metal), as even a tiny distance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Load vector – highest force is obtained only during pulling at a 90° angle. The shear force of the magnet along the plate is usually several times smaller (approx. 1/5 of the lifting capacity).
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Material type – ideal substrate is high-permeability steel. Hardened steels may attract less.
• Smoothness – full contact is obtained only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Thermal factor – high temperature weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity was measured using a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, however under parallel forces the holding force is lower. In addition, even a slight gap {between} the magnet and the plate decreases the holding force.