Neodymium Block Magnets

Overview - Neodymium Block Magnets

Neodymium (rare earth) NdFeB block magnets

Neodymium magnets or NdFeB block magnets are usually specified by their three dimensions such that the first two dimensions detail the size of each magnet pole face and the last dimension specifies the distance between the poles (the magnet is magnetized in the same direction as the last dimension). The NdFeB Neodymium block magnets could be NdFeB Neodymium rectangular magnets or NdFeB Neodymium square magnets, NdFeB Neodymium slab magnets or NdFeB Neodymium cube magnets. Any such shapes (rectangle, square, slab or cube) fall under NdFeB Neodymium block magnets.

Magnet Design for Alternative Magnetic Systems

For very tall magnets (where the height is larger than the pole face dimensions, the block magnets are referred to as bar magnets and such magnets have their own online section). The larger the pole face area the better the magnet will be at attracting through larger air gaps (the magnet will project a stronger field at distance).

Magnets can be stacked in multiples of their pole to pole distance (they will attract each other to build height) which will give increases in performance but increasing the magnet height further will eventually start to give less and less increase as the performance starts to plateau off. When this happens and more performance is required then a larger pole face area magnet is needed (magnetic design could be used to give an alternative magnetic system but we would have to discuss your application to assist you). The direction of magnetization is physically locked into the structure of the magnet - you cannot change it to be in a different axis (you would need to get another magnet produced).

Maximising Magnetic Pull

If you are clamping a magnet between two mild steel (ferromagnetic) plates you have a good magnetic circuit (with some leakage around the sides). But if you were to have two NdFeB Neodymium block magnets side by side in a N-S arrangement (they will attract extremely strongly in this way), you have an even better magnetic circuit with potentially even higher magnetic pull with very little air gap leakage involved and the magnets will be getting close to working at their maximum possible performance (assuming the steel does not magnetically saturate). Take this idea further and consider a checker-board effect (-N-S-N-S- etc) clamping between two mild steel sheets and you have a maximum pull force system limited only by the steel's ability to carry all the magnetic flux.