MW 9x3 / N38 - cylindrical magnet

Strengths and weaknesses of rare earth magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They retain magnetic properties for nearly ten years – the loss is just ~1% (according to analyses),
• They maintain their magnetic properties even under external field action,
• A magnet with a metallic silver surface has better aesthetics,
• Neodymium magnets deliver maximum magnetic induction on a small surface, which ensures high operational effectiveness,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of precise modeling and modifying to atypical conditions,
• Fundamental importance in future technologies – they find application in magnetic memories, electromotive mechanisms, precision medical tools, as well as complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which enables their usage in miniature devices

Drawbacks and weaknesses of neodymium magnets and ways of using them

• To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets experience a drop in power. 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
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in producing threads and complicated forms in magnets, we recommend using a housing - magnetic mount.
• Potential hazard to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which is particularly important in the context of child safety. It is also worth noting that small components of these devices are able to disrupt the diagnostic process medical when they are in the body.
• With budget limitations the cost of neodymium magnets is a challenge,

Maximum lifting force for a neodymium magnet – what contributes to it?

Breakaway force is the result of a measurement for the most favorable conditions, taking into account:

• with the contact of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a massiveness of min. 10 mm to ensure full flux closure
• with an ground contact surface
• with direct contact (no coatings)
• during pulling in a direction vertical to the mounting surface
• at room temperature

What influences lifting capacity in practice

In real-world applications, the real power results from a number of factors, listed from crucial:

• Clearance – existence of foreign body (paint, tape, gap) interrupts the magnetic circuit, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Angle of force application – highest force is available only during perpendicular pulling. The resistance to sliding of the magnet along the plate is typically many times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Steel type – mild steel attracts best. Alloy steels reduce magnetic properties and lifting capacity.
• Plate texture – ground elements guarantee perfect abutment, which improves force. Rough surfaces weaken the grip.
• Heat – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity was determined using a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, in contrast under parallel forces the holding force is lower. In addition, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.