MPL 40x10x4 / N38 - lamellar magnet

Strengths as well as weaknesses of NdFeB magnets.

Besides their exceptional magnetic power, neodymium magnets offer the following advantages:

• They do not lose strength, even over approximately ten years – the reduction in strength is only ~1% (theoretically),
• Magnets very well protect themselves against loss of magnetization caused by external fields,
• The use of an shiny finish of noble metals (nickel, gold, silver) causes the element to present itself better,
• Neodymium magnets achieve maximum magnetic induction on a their surface, which increases force concentration,
• 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 accurate shaping and adapting to precise conditions,
• Versatile presence in modern industrial fields – they are utilized in data components, electromotive mechanisms, advanced medical instruments, as well as technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which enables their usage in miniature devices

Characteristics of disadvantages of neodymium magnets: application proposals

• To avoid cracks under impact, we recommend using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their power 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
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• Limited ability of making threads in the magnet and complex forms - preferred is casing - mounting mechanism.
• Potential hazard resulting from small fragments of magnets are risky, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small components of these devices are able to be problematic in diagnostics medical in case of swallowing.
• Due to neodymium price, their price is higher than average,

Optimal lifting capacity of a neodymium magnet – what it depends on?

The declared magnet strength represents the maximum value, measured under ideal test conditions, namely:

• with the contact of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a thickness of min. 10 mm to avoid saturation
• with a surface perfectly flat
• without any insulating layer between the magnet and steel
• under vertical force direction (90-degree angle)
• at conditions approx. 20°C

What influences lifting capacity in practice

Holding efficiency is affected by specific conditions, mainly (from priority):

• Distance – existence of any layer (rust, tape, gap) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Load vector – highest force is available only during perpendicular pulling. The force required to slide of the magnet along the plate is standardly several times smaller (approx. 1/5 of the lifting capacity).
• Plate thickness – insufficiently thick sheet does not close the flux, causing part of the power to be lost to the other side.
• Metal type – different alloys attracts identically. High carbon content weaken the attraction effect.
• Smoothness – full contact is obtained only on polished steel. Any scratches and bumps create air cushions, weakening the magnet.
• Operating temperature – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under perpendicular forces, whereas under parallel forces the lifting capacity is smaller. In addition, even a slight gap {between} the magnet and the plate decreases the holding force.