UMS 16x6.5x3.5x5 / N38 - conical magnetic holder

Pros as well as cons of rare earth magnets.

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

• Their power remains stable, and after around 10 years it decreases only by ~1% (theoretically),
• They show high resistance to demagnetization induced by external field influence,
• The use of an shiny finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• The surface of neodymium magnets generates a unique magnetic field – this is a distinguishing feature,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures reaching 230°C and above...
• Thanks to freedom in forming and the capacity to adapt to client solutions,
• Universal use in advanced technology sectors – they are used in computer drives, electromotive mechanisms, diagnostic systems, and multitasking production systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets: weaknesses and usage proposals

• To avoid cracks under impact, we recommend using special steel holders. Such a solution secures the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation and corrosion.
• Limited ability of making threads in the magnet and complex forms - preferred is cover - magnetic holder.
• Potential hazard to health – tiny shards of magnets are risky, in case of ingestion, which is particularly important in the context of child health protection. Additionally, tiny parts of these magnets are able to disrupt the diagnostic process medical in case of swallowing.
• With budget limitations the cost of neodymium magnets can be a barrier,

Breakaway strength of the magnet in ideal conditions – what contributes to it?

The lifting capacity listed is a measurement result performed under standard conditions:

• on a block made of mild steel, optimally conducting the magnetic flux
• whose thickness reaches at least 10 mm
• characterized by smoothness
• under conditions of gap-free contact (metal-to-metal)
• under perpendicular application of breakaway force (90-degree angle)
• in neutral thermal conditions

Practical lifting capacity: influencing factors

Bear in mind that the working load will differ depending on the following factors, in order of importance:

• Clearance – existence of foreign body (rust, tape, air) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Angle of force application – maximum parameter is reached only during perpendicular pulling. The resistance to sliding of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin plate does not close the flux, causing part of the power to be escaped into the air.
• Plate material – low-carbon steel attracts best. Alloy steels reduce magnetic permeability and lifting capacity.
• Surface finish – ideal contact is possible only on polished steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Thermal environment – heating the magnet results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate reduces the load capacity.