AM ucho [M8] - magnetic accessories

Pros as well as cons of rare earth magnets.

Besides their exceptional pulling force, neodymium magnets offer the following advantages:

• Their power remains stable, and after around 10 years it drops only by ~1% (according to research),
• Magnets perfectly defend themselves against demagnetization caused by ambient magnetic noise,
• Thanks to the smooth finish, the surface of nickel, gold-plated, or silver gives an visually attractive appearance,
• Magnets have huge magnetic induction on the working surface,
• With the right combination of compounds, they reach excellent thermal stability, enabling operation at or above 230°C (depending on the form),
• In view of the option of free molding and adaptation to custom solutions, NdFeB magnets can be created in a variety of geometric configurations, which increases their versatility,
• Key role in high-tech industry – they find application in data components, electric motors, medical devices, as well as multitasking production systems.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Drawbacks and weaknesses of neodymium magnets: tips and applications.

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a special holder, which not only protects them against impacts but also increases their durability
• Neodymium magnets decrease their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Due to limitations in realizing threads and complicated shapes in magnets, we propose using cover - magnetic mechanism.
• Potential hazard resulting from small fragments of magnets are risky, if swallowed, which is particularly important in the context of child safety. Additionally, tiny parts of these products can disrupt the diagnostic process medical when they are in the body.
• Due to complex production process, their price exceeds standard values,

Breakaway strength of the magnet in ideal conditions – what it depends on?

The load parameter shown represents the peak performance, obtained under laboratory conditions, specifically:

• on a block made of structural steel, perfectly concentrating the magnetic field
• possessing a massiveness of minimum 10 mm to avoid saturation
• characterized by lack of roughness
• without the slightest clearance between the magnet and steel
• during pulling in a direction vertical to the plane
• in neutral thermal conditions

Impact of factors on magnetic holding capacity in practice

Holding efficiency is influenced by working environment parameters, including (from priority):

• Gap between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Load vector – highest force is reached only during perpendicular pulling. The force required to slide of the magnet along the plate is typically many times smaller (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin steel does not close the flux, causing part of the power to be lost into the air.
• Material type – the best choice is pure iron steel. Cast iron may have worse magnetic properties.
• Surface quality – the more even the surface, the larger the contact zone and stronger the hold. Roughness acts like micro-gaps.
• Temperature – heating the magnet causes a temporary drop of force. Check the thermal limit for a given model.

* Holding force was measured on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under attempts to slide the magnet the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate reduces the lifting capacity.