RM R7 SUPER - 13000 Gs / N52 - magnetic distributor

Strengths as well as weaknesses of neodymium magnets.

Apart from their strong magnetism, neodymium magnets have these key benefits:

• They have stable power, and over around 10 years their performance decreases symbolically – ~1% (in testing),
• They maintain their magnetic properties even under strong external field,
• A magnet with a shiny gold surface looks better,
• Magnets are distinguished by extremely high magnetic induction on the outer side,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Possibility of custom machining as well as optimizing to atypical requirements,
• Significant place in future technologies – they are commonly used in mass storage devices, motor assemblies, advanced medical instruments, also complex engineering applications.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Cons of neodymium magnets and proposals for their use:

• They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only protects the magnet but also improves its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They oxidize in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic mount, due to difficulties in realizing threads inside the magnet and complex shapes.
• Possible danger related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, tiny parts of these products are able to disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Optimal lifting capacity of a neodymium magnet – what contributes to it?

Holding force of 0 kg is a measurement result conducted under standard conditions:

• with the use of a yoke made of special test steel, ensuring maximum field concentration
• with a thickness of at least 10 mm
• with an polished contact surface
• with direct contact (no coatings)
• for force applied at a right angle (in the magnet axis)
• at temperature approx. 20 degrees Celsius

Lifting capacity in real conditions – factors

During everyday use, the actual holding force depends on many variables, presented from the most important:

• Gap (betwixt the magnet and the metal), because even a microscopic distance (e.g. 0.5 mm) leads to a decrease in force by up to 50% (this also applies to varnish, rust or debris).
• Direction of force – maximum parameter is obtained only during pulling at a 90° angle. The shear force of the magnet along the plate is typically several times smaller (approx. 1/5 of the lifting capacity).
• Plate thickness – insufficiently thick plate causes magnetic saturation, causing part of the flux to be escaped to the other side.
• Steel type – low-carbon steel gives the best results. Higher carbon content reduce magnetic properties and lifting capacity.
• Surface structure – the more even the plate, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
• Heat – NdFeB sinters have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was determined with the use of a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under shearing force the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the holding force.