CM PML-10 / N45 - magnetic gripper

Advantages as well as disadvantages of neodymium magnets.

Apart from their notable magnetic energy, neodymium magnets have these key benefits:

• They retain attractive force for around ten years – the loss is just ~1% (according to analyses),
• They maintain their magnetic properties even under strong external field,
• A magnet with a metallic silver surface looks better,
• Magnetic induction on the working layer of the magnet turns out to be strong,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures reaching 230°C and above...
• Thanks to the option of free forming and adaptation to specialized requirements, NdFeB magnets can be created in a broad palette of geometric configurations, which amplifies use scope,
• Wide application in innovative solutions – they are used in magnetic memories, electromotive mechanisms, medical devices, and multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in compact dimensions, which enables their usage in miniature devices

Drawbacks and weaknesses of neodymium magnets: tips and applications.

• Brittleness is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a steel housing, which not only protects them against impacts but also raises their durability
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• We recommend casing - magnetic mechanism, due to difficulties in producing threads inside the magnet and complicated forms.
• Potential hazard to health – tiny shards of magnets are risky, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Additionally, tiny parts of these products are able to disrupt the diagnostic process medical in case of swallowing.
• Due to complex production process, their price exceeds standard values,

Breakaway strength of the magnet in ideal conditions – what it depends on?

Breakaway force was determined for the most favorable conditions, taking into account:

• using a sheet made of high-permeability steel, serving as a ideal flux conductor
• with a cross-section no less than 10 mm
• with an ideally smooth touching surface
• without any air gap between the magnet and steel
• for force applied at a right angle (pull-off, not shear)
• in neutral thermal conditions

Determinants of lifting force in real conditions

In real-world applications, the actual lifting capacity depends on many variables, presented from the most important:

• Clearance – the presence of foreign body (paint, tape, gap) interrupts the magnetic circuit, which lowers capacity steeply (even by 50% at 0.5 mm).
• Load vector – highest force is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the surface is usually many times smaller (approx. 1/5 of the lifting capacity).
• Plate thickness – insufficiently thick steel does not accept the full field, causing part of the flux to be escaped into the air.
• Material type – ideal substrate is pure iron steel. Cast iron may generate lower lifting capacity.
• Surface finish – full contact is obtained only on polished steel. Any scratches and bumps reduce the real contact area, reducing force.
• Operating temperature – NdFeB sinters have a sensitivity to temperature. At higher temperatures they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity was determined with the use of a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under shearing force the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet and the plate reduces the lifting capacity.