SM 32x275 [2xM8] / N52 - magnetic separator

Strengths as well as weaknesses of neodymium magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They do not lose strength, even after approximately ten years – the decrease in lifting capacity is only ~1% (based on measurements),
• Neodymium magnets are exceptionally resistant to demagnetization caused by magnetic disturbances,
• The use of an aesthetic layer of noble metals (nickel, gold, silver) causes the element to look better,
• Magnetic induction on the top side of the magnet is very high,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Due to the ability of accurate forming and adaptation to custom needs, neodymium magnets can be created in a wide range of forms and dimensions, which expands the range of possible applications,
• Wide application in modern industrial fields – they are commonly used in magnetic memories, electromotive mechanisms, diagnostic systems, also technologically advanced constructions.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only shields the magnet but also increases its resistance to damage
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in creating nuts and complicated shapes in magnets, we propose using casing - magnetic mount.
• Possible danger resulting from small fragments of magnets are risky, in case of ingestion, which is particularly important in the context of child health protection. Furthermore, tiny parts of these magnets can complicate diagnosis 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

Best holding force of the magnet in ideal parameters – what it depends on?

The declared magnet strength concerns the maximum value, measured under optimal environment, meaning:

• with the use of a sheet made of special test steel, ensuring maximum field concentration
• with a thickness no less than 10 mm
• characterized by smoothness
• under conditions of gap-free contact (metal-to-metal)
• for force applied at a right angle (in the magnet axis)
• at ambient temperature room level

Practical lifting capacity: influencing factors

It is worth knowing that the working load may be lower subject to elements below, starting with the most relevant:

• Space between magnet and steel – every millimeter of separation (caused e.g. by varnish or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Angle of force application – highest force is available only during pulling at a 90° angle. The shear force of the magnet along the surface is usually several times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Metal type – not every steel attracts identically. Alloy additives weaken the interaction with the magnet.
• Surface structure – the more even the surface, the larger the contact zone and higher the lifting capacity. Roughness creates an air distance.
• Thermal environment – heating the magnet results in weakening of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity was assessed by applying a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, however under parallel forces the load capacity is reduced by as much as fivefold. In addition, even a slight gap {between} the magnet and the plate decreases the lifting capacity.