MP 30x6x10 / N38 - ring magnet

Advantages and disadvantages of neodymium magnets.

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

• They retain attractive force for almost ten years – the loss is just ~1% (in theory),
• Neodymium magnets are distinguished by exceptionally resistant to demagnetization caused by magnetic disturbances,
• In other words, due to the aesthetic layer of silver, the element looks attractive,
• Magnets are distinguished by exceptionally strong magnetic induction on the surface,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Thanks to the potential of accurate shaping and adaptation to custom requirements, NdFeB magnets can be manufactured in a variety of forms and dimensions, which increases their versatility,
• Universal use in modern industrial fields – they are used in HDD drives, electric drive systems, medical equipment, also technologically advanced constructions.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets and proposals for their use:

• Brittleness 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 increases their durability
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation as well as corrosion.
• Due to limitations in creating nuts and complicated shapes in magnets, we recommend using cover - magnetic mount.
• Health risk resulting from small fragments of magnets can be dangerous, in case of ingestion, which becomes key in the context of child safety. It is also worth noting that small elements of these products can be problematic in diagnostics medical when they are in the body.
• With large orders the cost of neodymium magnets can be a barrier,

Maximum magnetic pulling force – what it depends on?

The load parameter shown concerns the peak performance, obtained under ideal test conditions, specifically:

• on a block made of mild steel, effectively closing the magnetic field
• with a thickness no less than 10 mm
• with an ideally smooth contact surface
• without any insulating layer between the magnet and steel
• for force applied at a right angle (pull-off, not shear)
• in stable room temperature

What influences lifting capacity in practice

Bear in mind that the working load will differ depending on elements below, in order of importance:

• Distance – the presence of any layer (rust, tape, air) acts as an insulator, which lowers capacity steeply (even by 50% at 0.5 mm).
• Direction of force – highest force is obtained only during perpendicular pulling. The force required to slide of the magnet along the plate is usually many times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin steel does not accept the full field, causing part of the flux to be escaped into the air.
• Material composition – different alloys attracts identically. High carbon content worsen the attraction effect.
• Plate texture – smooth surfaces ensure maximum contact, which improves force. Rough surfaces reduce efficiency.
• Temperature influence – hot environment weakens magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity testing was carried out on a smooth plate of optimal thickness, under a perpendicular pulling force, whereas under attempts to slide the magnet the load capacity is reduced by as much as 5 times. Moreover, even a small distance {between} the magnet’s surface and the plate reduces the holding force.