HH 42x8.8 [M6] / N38 - through hole magnetic holder

Strengths as well as weaknesses of rare earth magnets.

Besides their tremendous field intensity, neodymium magnets offer the following advantages:

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (in laboratory conditions),
• They possess excellent resistance to magnetism drop as a result of opposing magnetic fields,
• By covering with a shiny coating of gold, the element has an elegant look,
• Magnetic induction on the top side of the magnet turns out to be very high,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Thanks to flexibility in forming and the ability to customize to individual projects,
• Fundamental importance in high-tech industry – they serve a role in magnetic memories, electric drive systems, diagnostic systems, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which makes them useful in small systems

Cons of neodymium magnets: application proposals

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a strong case, which not only secures them against impacts but also increases their durability
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 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 as well as corrosion.
• Due to limitations in creating threads and complex shapes in magnets, we propose using a housing - magnetic mount.
• Possible danger to health – tiny shards of magnets are risky, in case of ingestion, which becomes key in the aspect of protecting the youngest. Furthermore, tiny parts of these devices can be problematic in diagnostics medical after entering 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 force parameter is a result of laboratory testing performed under the following configuration:

• using a sheet made of low-carbon steel, acting as a magnetic yoke
• with a thickness of at least 10 mm
• with an polished touching surface
• under conditions of no distance (metal-to-metal)
• under vertical application of breakaway force (90-degree angle)
• in temp. approx. 20°C

Magnet lifting force in use – key factors

Holding efficiency impacted by specific conditions, including (from most important):

• Clearance – the presence of foreign body (paint, tape, air) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is usually several times smaller (approx. 1/5 of the lifting capacity).
• Steel thickness – too thin steel causes magnetic saturation, causing part of the power to be wasted to the other side.
• Chemical composition of the base – mild steel attracts best. Alloy steels decrease magnetic permeability and lifting capacity.
• Smoothness – ideal contact is obtained only on polished steel. Rough texture reduce the real contact area, weakening the magnet.
• Thermal environment – temperature increase results in weakening of force. It is worth remembering the thermal limit for a given model.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet and the plate decreases the lifting capacity.