CM PML-3 / N45 - magnetic gripper

Advantages as well as disadvantages of neodymium magnets.

Besides their tremendous pulling force, neodymium magnets offer the following advantages:

• Their strength is maintained, and after approximately 10 years it drops only by ~1% (according to research),
• They feature excellent resistance to magnetic field loss due to opposing magnetic fields,
• By applying a smooth coating of nickel, the element presents an elegant look,
• Neodymium magnets deliver maximum magnetic induction on a small area, which allows for strong attraction,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Considering the option of free forming and adaptation to individualized projects, magnetic components can be modeled in a wide range of geometric configurations, which expands the range of possible applications,
• Significant place in high-tech industry – they serve a role in mass storage devices, electric motors, medical devices, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which makes them useful in small systems

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also improves its resistance to damage
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in realizing nuts and complicated shapes in magnets, we propose using cover - magnetic mechanism.
• Health risk related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the aspect of protecting the youngest. Additionally, tiny parts of these magnets are able to complicate diagnosis medical after entering the body.
• Due to expensive raw materials, their price is higher than average,

Optimal lifting capacity of a neodymium magnet – what affects it?

The force parameter is a result of laboratory testing conducted under the following configuration:

• using a plate made of low-carbon steel, functioning as a circuit closing element
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by even structure
• under conditions of gap-free contact (surface-to-surface)
• during pulling in a direction vertical to the mounting surface
• at ambient temperature approx. 20 degrees Celsius

Impact of factors on magnetic holding capacity in practice

In practice, the actual holding force depends on several key aspects, presented from the most important:

• Space between surfaces – every millimeter of distance (caused e.g. by varnish or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Plate thickness – insufficiently thick steel does not accept the full field, causing part of the power to be escaped into the air.
• Chemical composition of the base – mild steel attracts best. Alloy admixtures lower magnetic properties and lifting capacity.
• Surface condition – smooth surfaces guarantee perfect abutment, which increases force. Uneven metal weaken the grip.
• Thermal environment – temperature increase results in weakening of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was determined by applying a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, in contrast under shearing force the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet’s surface and the plate decreases the load capacity.