China Neodymium And Ferrite Magnets Manufacturer & Supplier 
5cm long magnets, also known as 50mm length bar magnet blocks, are mainly used in machinery and equipment, industry, etc. You need to provide specific grades and sizes, magnetization direction, etc., if you want to know the surface magnetic field strength of 50mm long neodymium-iron-boron magnets.Usually, common neodymium-iron-boron grades, such as N35, N42, N52, etc., each grade has a different residual magnetic induction strength and magnetic energy product.
Below is the gauss value of NdFeB of 50mm length bar compiled by Courage Xiao Fu for your reference;
50x13x3mm, N40 grade surface magnetic field strength about 1400 gauss.
50x16x4mm, N40 performance surface magnetic about 1650 gauss.
N40 grade 50x25x3mm rectangular block magnet surface magnetism of approximately 860 gauss.
N40 grade 50x7x4.5 block magnet table magnetism about 2990gs.
NdFeB 50mm bar magnet 50x15x10mm sample
N40 grade 50x10x4.5mm bar neodymium magnet table magnet strength is about 2450 gs or so.
N40 grade 50x10x2.5mm thickness magnetization gauss about 1670.
N38 grade 5x10x50mm (lengthwise magnetization) surface gauss is about 4030 gauss.
50x20x10 NdFeB block magnet N35 grade surface magnetization about 3030 gauss.
50x30x5mm bar neodymium magnet with N35 grade surface magnetization is around 1360 gauss.
If it is made of ferrite, the surface magnetic strength is not so high.
The above is about 5cm long NdFeB block magnets surface gauss value introduction, by the Courage permanent magnet manufacturer Xiao Fu finishing editing, such as the need for quotations, to do samples of 50mm long magnets can contact our company, can be on the surface of the 1 or more countersunk holes, shaped processing and so on.
Magnet Gauss Estimation Tool;
Neodymium Disc & Block Magnet Surface Gauss Online Calculator
Related length 50mm bar strong magnet;
Long flat neodymium bar magnets 50mm x 5mm x 2.5mm