MW 38x3.5 / N38 - cylindrical magnet

Strengths and weaknesses of NdFeB magnets.

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

• Their magnetic field is durable, and after around 10 years it decreases only by ~1% (theoretically),
• They feature excellent resistance to weakening of magnetic properties as a result of external fields,
• By using a smooth coating of silver, the element has an nice look,
• Magnetic induction on the working layer of the magnet turns out to be exceptional,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling functioning at temperatures reaching 230°C and above...
• Possibility of accurate modeling and optimizing to complex needs,
• Fundamental importance in innovative solutions – they are used in magnetic memories, motor assemblies, medical equipment, and complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which makes them useful in small systems

Problematic aspects of neodymium magnets: tips and applications.

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a strong case, which not only secures them against impacts but also raises their durability
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 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 resistant to moisture, when using outdoors
• Limited ability of making nuts in the magnet and complex shapes - preferred is cover - magnetic holder.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. Furthermore, small elements of these devices can be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum lifting force for a neodymium magnet – what affects it?

The lifting capacity listed is a measurement result conducted under standard conditions:

• on a plate made of mild steel, optimally conducting the magnetic flux
• with a cross-section no less than 10 mm
• with an polished contact surface
• under conditions of no distance (surface-to-surface)
• under perpendicular force direction (90-degree angle)
• in stable room temperature

Lifting capacity in real conditions – factors

In real-world applications, the actual lifting capacity is determined by a number of factors, listed from crucial:

• Distance (between the magnet and the metal), as even a microscopic clearance (e.g. 0.5 mm) results in a reduction in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Steel grade – the best choice is high-permeability steel. Hardened steels may generate lower lifting capacity.
• Surface structure – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
• Temperature influence – hot environment weakens pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under attempts to slide the magnet the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate lowers the holding force.