UMP 75x24 [M8+M10] GW F 200 kg - search holder

Strengths and weaknesses of neodymium magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They do not lose strength, even after nearly 10 years – the decrease in lifting capacity is only ~1% (according to tests),
• Neodymium magnets are characterized by highly resistant to magnetic field loss caused by magnetic disturbances,
• Thanks to the elegant finish, the surface of nickel, gold-plated, or silver-plated gives an modern appearance,
• Magnetic induction on the working layer of the magnet remains impressive,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for action at temperatures reaching 230°C and above...
• Thanks to flexibility in shaping and the capacity to customize to client solutions,
• Significant place in future technologies – they serve a role in computer drives, electromotive mechanisms, medical devices, and modern systems.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Disadvantages of NdFeB magnets:

• At very strong impacts they can crack, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• NdFeB 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 extremely resistant to heat
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• We suggest a housing - magnetic mount, due to difficulties in creating threads inside the magnet and complicated forms.
• Health risk resulting from small fragments of magnets can be dangerous, if swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, small elements of these magnets are able to be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum lifting capacity of the magnet – what it depends on?

The lifting capacity listed is a result of laboratory testing performed under standard conditions:

• with the contact of a sheet made of low-carbon steel, ensuring full magnetic saturation
• whose transverse dimension reaches at least 10 mm
• with a plane free of scratches
• without the slightest clearance between the magnet and steel
• during pulling in a direction perpendicular to the mounting surface
• in neutral thermal conditions

Determinants of lifting force in real conditions

Please note that the application force may be lower subject to elements below, starting with the most relevant:

• Space between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) diminishes the pulling force, often by half at just 0.5 mm.
• Load vector – maximum parameter is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is standardly many times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Steel grade – ideal substrate is high-permeability steel. Stainless steels may have worse magnetic properties.
• Surface quality – the more even the surface, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Operating temperature – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was determined using a polished steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, however under parallel forces the holding force is lower. Additionally, even a slight gap {between} the magnet’s surface and the plate reduces the holding force.