MW 28.9x10 / N38 - cylindrical magnet

Pros as well as cons of NdFeB magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They do not lose strength, even during around 10 years – the reduction in power is only ~1% (theoretically),
• They do not lose their magnetic properties even under close interference source,
• Thanks to the elegant finish, the layer of nickel, gold, or silver gives an clean appearance,
• Neodymium magnets achieve maximum magnetic induction on a small area, which ensures high operational effectiveness,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures reaching 230°C and above...
• Possibility of individual creating as well as optimizing to concrete requirements,
• Significant place in high-tech industry – they serve a role in hard drives, electromotive mechanisms, diagnostic systems, and modern systems.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Disadvantages of neodymium magnets:

• At very strong impacts they can crack, therefore we advise placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• 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, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 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 immune to moisture, in case of application outdoors
• We suggest a housing - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complicated forms.
• Potential hazard to health – tiny shards of magnets pose a threat, in case of ingestion, which becomes key in the context of child health protection. Furthermore, tiny parts of these devices can be problematic in diagnostics medical when they are in the body.
• With large orders the cost of neodymium magnets can be a barrier,

Magnetic strength at its maximum – what it depends on?

Information about lifting capacity was determined for ideal contact conditions, assuming:

• on a block made of mild steel, optimally conducting the magnetic field
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with an ground touching surface
• with total lack of distance (no paint)
• for force acting at a right angle (pull-off, not shear)
• at room temperature

Magnet lifting force in use – key factors

Real force is affected by specific conditions, including (from most important):

• Clearance – existence of foreign body (rust, tape, air) acts as an insulator, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Load vector – maximum parameter is obtained only during pulling at a 90° angle. The resistance to sliding of the magnet along the plate is usually several times lower (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Chemical composition of the base – mild steel gives the best results. Higher carbon content reduce magnetic properties and lifting capacity.
• Surface quality – the more even the plate, the better the adhesion and stronger the hold. Roughness acts like micro-gaps.
• Operating temperature – neodymium magnets have a sensitivity to temperature. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity testing was conducted on plates with a smooth surface of suitable thickness, under perpendicular forces, in contrast under parallel forces the load capacity is reduced by as much as 75%. In addition, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.