MW 8x15 / N38 - cylindrical magnet

Pros and cons of rare earth magnets.

Apart from their superior power, neodymium magnets have these key benefits:

• They have stable power, and over more than ten years their performance decreases symbolically – ~1% (in testing),
• They have excellent resistance to magnetism drop as a result of external magnetic sources,
• By using a smooth layer of nickel, the element has an professional look,
• They feature high magnetic induction at the operating surface, which improves attraction properties,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Due to the ability of flexible forming and customization to unique solutions, NdFeB magnets can be modeled in a variety of shapes and sizes, which makes them more universal,
• Fundamental importance in electronics industry – they serve a role in magnetic memories, drive modules, medical devices, and modern systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons of neodymium magnets and ways of using them

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They oxidize in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We recommend casing - magnetic mount, due to difficulties in creating threads inside the magnet and complicated shapes.
• Possible danger related to microscopic parts of magnets are risky, if swallowed, which becomes key in the context of child safety. Furthermore, small elements of these products can complicate diagnosis medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum holding power of the magnet – what it depends on?

The specified lifting capacity represents the limit force, measured under ideal test conditions, namely:

• with the application of a yoke made of low-carbon steel, ensuring maximum field concentration
• possessing a massiveness of min. 10 mm to ensure full flux closure
• characterized by even structure
• with direct contact (no coatings)
• during pulling in a direction perpendicular to the mounting surface
• at room temperature

Determinants of lifting force in real conditions

In real-world applications, the actual lifting capacity depends on a number of factors, ranked from the most important:

• Distance (betwixt the magnet and the plate), since even a very small clearance (e.g. 0.5 mm) can cause a decrease in force by up to 50% (this also applies to paint, corrosion or dirt).
• Load vector – highest force is available only during pulling at a 90° angle. The shear force of the magnet along the plate is typically many times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Material type – ideal substrate is pure iron steel. Stainless steels may have worse magnetic properties.
• Surface finish – full contact is obtained only on polished steel. Rough texture create air cushions, weakening the magnet.
• Temperature influence – high temperature reduces pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was performed on a smooth plate of suitable thickness, under a perpendicular pulling force, in contrast under parallel forces the load capacity is reduced by as much as 5 times. Additionally, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.