CM PML-10 / N45 - magnetic gripper

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They do not lose their magnetism, even after nearly ten years – the loss of strength is only ~1% (theoretically),
• Their ability to resist magnetic interference from external fields is among the best,
• By applying a bright layer of silver, the element gains a modern look,
• Magnetic induction on the surface of these magnets is impressively powerful,
• Thanks to their high temperature resistance, they can operate (depending on the form) even at temperatures up to 230°C or more,
• With the option for fine forming and personalized design, these magnets can be produced in various shapes and sizes, greatly improving application potential,
• Wide application in cutting-edge sectors – they serve a purpose in hard drives, rotating machines, diagnostic apparatus along with sophisticated instruments,
• Thanks to their efficiency per volume, small magnets offer high magnetic performance, while occupying minimal space,

Disadvantages of rare earth magnets:

• They are prone to breaking when subjected to a powerful impact. If the magnets are exposed to physical collisions, it is advisable to use in a metal holder. The steel housing, in the form of a holder, protects the magnet from fracture and additionally reinforces its overall resistance,
• Magnets lose field strength when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible power drop (influenced by the magnet’s profile). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Due to corrosion risk in humid conditions, it is advisable to use sealed magnets made of protective material for outdoor use,
• Limited ability to create threads in the magnet – the use of a housing is recommended,
• Health risk from tiny pieces may arise, if ingested accidentally, which is significant in the context of child safety. Additionally, miniature parts from these products have the potential to disrupt scanning once in the system,
• In cases of tight budgets, neodymium magnet cost may be a barrier,

Maximum lifting capacity of the magnet – what contributes to it?

The given holding capacity of the magnet means the highest holding force, assessed under optimal conditions, that is:

• with the use of low-carbon steel plate serving as a magnetic yoke
• having a thickness of no less than 10 millimeters
• with a smooth surface
• with no separation
• under perpendicular detachment force
• at room temperature

Lifting capacity in real conditions – factors

The lifting capacity of a magnet is determined by in practice key elements, according to their importance:

• Air gap between the magnet and the plate, because even a very small distance (e.g. 0.5 mm) can cause a drop in lifting force of up to 50%.
• Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
• Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
• Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
• Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
• Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Lifting capacity testing was conducted on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, whereas under shearing force the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate lowers the lifting capacity.