CM PML-3 / N45 - magnetic gripper

Pros as well as cons of neodymium magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• Their magnetic field is durable, and after around 10 years it decreases only by ~1% (according to research),
• Magnets perfectly defend themselves against loss of magnetization caused by foreign field sources,
• The use of an metallic finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Magnetic induction on the working part of the magnet remains exceptional,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Thanks to freedom in designing and the capacity to modify to unusual requirements,
• Universal use in future technologies – they are commonly used in data components, electric motors, medical devices, as well as multitasking production systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only protects the magnet but also improves its resistance to damage
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• They oxidize in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We recommend casing - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complex forms.
• Potential hazard to health – tiny shards of magnets pose a threat, if swallowed, which is particularly important in the context of child health protection. Furthermore, small elements of these devices can complicate diagnosis medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Highest magnetic holding force – what contributes to it?

The force parameter is a theoretical maximum value conducted under the following configuration:

• with the application of a sheet made of special test steel, guaranteeing maximum field concentration
• possessing a massiveness of min. 10 mm to ensure full flux closure
• characterized by smoothness
• under conditions of ideal adhesion (surface-to-surface)
• for force acting at a right angle (pull-off, not shear)
• at ambient temperature approx. 20 degrees Celsius

Magnet lifting force in use – key factors

Effective lifting capacity is affected by working environment parameters, including (from most important):

• Gap (betwixt the magnet and the plate), since even a microscopic distance (e.g. 0.5 mm) results in a decrease in force by up to 50% (this also applies to varnish, corrosion or debris).
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Plate thickness – too thin steel causes magnetic saturation, causing part of the flux to be wasted into the air.
• Material composition – not every steel reacts the same. Alloy additives worsen the attraction effect.
• Smoothness – ideal contact is obtained only on polished steel. Any scratches and bumps create air cushions, reducing force.
• Temperature – temperature increase causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity was assessed by applying a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under parallel forces the holding force is lower. Moreover, even a small distance {between} the magnet and the plate decreases the lifting capacity.