UMGZ 20x15x7 [M4] GZ / N38 - magnetic holder external thread

Strengths and weaknesses of NdFeB magnets.

Apart from their consistent holding force, neodymium magnets have these key benefits:

• They have stable power, and over more than ten years their attraction force decreases symbolically – ~1% (in testing),
• They have excellent resistance to magnetic field loss due to external fields,
• The use of an shiny finish of noble metals (nickel, gold, silver) causes the element to look better,
• The surface of neodymium magnets generates a maximum magnetic field – this is a distinguishing feature,
• 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 detailed machining and adapting to precise conditions,
• Universal use in modern industrial fields – they serve a role in magnetic memories, electromotive mechanisms, precision medical tools, and multitasking production systems.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a special holder, which not only secures them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets experience a drop in strength. Often, when the temperature exceeds 80°C, their strength 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• Due to limitations in creating nuts and complex shapes in magnets, we recommend using cover - magnetic mechanism.
• Health risk related to microscopic parts of magnets are risky, when accidentally swallowed, which is particularly important in the context of child safety. It is also worth noting that small elements of these magnets can disrupt the diagnostic process medical when they are in the body.
• With mass production the cost of neodymium magnets is a challenge,

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

The declared magnet strength refers to the limit force, measured under ideal test conditions, specifically:

• using a sheet made of mild steel, functioning as a circuit closing element
• whose transverse dimension reaches at least 10 mm
• with an ideally smooth touching surface
• under conditions of no distance (metal-to-metal)
• for force applied at a right angle (pull-off, not shear)
• at standard ambient temperature

Key elements affecting lifting force

Effective lifting capacity impacted by specific conditions, mainly (from priority):

• Distance – the presence of any layer (paint, dirt, air) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is reached only during pulling at a 90° angle. The resistance to sliding of the magnet along the plate is usually several times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Material type – the best choice is high-permeability steel. Stainless steels may attract less.
• Plate texture – ground elements guarantee perfect abutment, which improves force. Rough surfaces reduce efficiency.
• Temperature – temperature increase results in weakening of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under a perpendicular pulling force, however under attempts to slide the magnet the load capacity is reduced by as much as 5 times. In addition, even a slight gap {between} the magnet and the plate reduces the lifting capacity.