MPL 40x18x10 SH / N38 - lamellar magnet

Strengths and weaknesses of NdFeB magnets.

Besides their exceptional strength, neodymium magnets offer the following advantages:

• They retain full power for nearly 10 years – the loss is just ~1% (in theory),
• Neodymium magnets are distinguished by highly resistant to demagnetization caused by external interference,
• In other words, due to the reflective finish of gold, the element looks attractive,
• Neodymium magnets create maximum magnetic induction on a small surface, which allows for strong attraction,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Possibility of precise shaping and modifying to defined applications,
• Key role in modern industrial fields – they serve a role in computer drives, electric motors, precision medical tools, also other advanced devices.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets and ways of using them

• To avoid cracks under impact, we recommend using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• Due to limitations in producing nuts and complex shapes in magnets, we propose using cover - magnetic mechanism.
• Potential hazard related to microscopic parts of magnets are risky, if swallowed, which gains importance in the aspect of protecting the youngest. Additionally, small elements of these products can be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Magnetic strength at its maximum – what contributes to it?

The load parameter shown concerns the maximum value, obtained under optimal environment, specifically:

• using a sheet made of low-carbon steel, functioning as a magnetic yoke
• whose thickness reaches at least 10 mm
• with an ideally smooth contact surface
• with direct contact (without coatings)
• for force applied at a right angle (pull-off, not shear)
• in stable room temperature

Lifting capacity in real conditions – factors

Bear in mind that the magnet holding may be lower depending on the following factors, in order of importance:

• Space between surfaces – every millimeter of distance (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Load vector – maximum parameter is obtained only during perpendicular pulling. The shear force of the magnet along the plate is standardly many times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Chemical composition of the base – low-carbon steel attracts best. Alloy steels reduce magnetic permeability and holding force.
• Plate texture – ground elements ensure maximum contact, which increases force. Uneven metal reduce efficiency.
• Temperature – heating the magnet causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Holding force was checked 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 reduces the holding force.