UMGW 42x20x9 [M6] GW / N38 - magnetic holder internal thread

Strengths as well as weaknesses of neodymium magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• Their power remains stable, and after approximately 10 years it decreases only by ~1% (theoretically),
• They have excellent resistance to magnetism drop as a result of opposing magnetic fields,
• Thanks to the reflective finish, the surface of nickel, gold, or silver gives an elegant appearance,
• Neodymium magnets deliver maximum magnetic induction on a small surface, which increases force concentration,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of detailed shaping and modifying to individual requirements,
• Key role in innovative solutions – they are commonly used in data components, electromotive mechanisms, medical equipment, as well as complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer high power in compact dimensions, which allows their use in small systems

Characteristics of disadvantages of neodymium magnets: weaknesses and usage proposals

• At very strong impacts they can break, therefore we recommend placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their strength 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
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• We suggest casing - magnetic holder, due to difficulties in realizing nuts inside the magnet and complex shapes.
• Health risk related to microscopic parts of magnets pose a threat, if swallowed, which is particularly important in the context of child health protection. Additionally, small elements of these magnets are able to disrupt the diagnostic process medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what it depends on?

Holding force of 66 kg is a theoretical maximum value executed under standard conditions:

• with the application of a sheet made of special test steel, guaranteeing full magnetic saturation
• with a thickness no less than 10 mm
• with a surface cleaned and smooth
• without any clearance between the magnet and steel
• for force applied at a right angle (pull-off, not shear)
• in stable room temperature

Lifting capacity in real conditions – factors

During everyday use, the actual lifting capacity is determined by a number of factors, ranked from most significant:

• Space between surfaces – every millimeter of distance (caused e.g. by veneer or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – highest force is obtained only during perpendicular pulling. The force required to slide of the magnet along the plate is usually many times smaller (approx. 1/5 of the lifting capacity).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of converting into lifting capacity.
• Steel grade – the best choice is high-permeability steel. Stainless steels may attract less.
• Surface finish – ideal contact is obtained only on smooth steel. Any scratches and bumps create air cushions, weakening the magnet.
• Temperature – heating the magnet causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was assessed by applying a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the holding force is lower. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.