China Neodymium And Ferrite Magnets Manufacturer & Supplier 
NdFeB (Neodymium Magnet) is an alloy composed of praseodymium-neodymium, iron and boron, which is one of the most excellent permanent magnetic materials at present, with the advantages of high magnetic energy product, high coercivity and high cost performance.
When we say NdFeB, we generally mean sintered NdFeB, whose main elements include neodymium, iron, dysprosium, boron and other genera, of which the content of iron accounts for about 65%, the rare earth elements praseodymium, neodymium, and other elements account for about 30%, the remaining about 5% boron, as well as other trace elements, and therefore NdFeB's density is close to that of iron (7.86g/cm³), with a density of about 7.5-7.7g/cm³. Converted, this is 7700kg/m³.
Rectangular neodymium magnet with 2 countersunk holes
In general, the higher the magnetic energy product and temperature resistance grade, the higher the density, this is due to the high temperature resistance grade NdFeB magnets with heavy rare earth elements added, thus making their density higher. For example:
N35-N45 grade neodymium magnet density is about 7.5g/cm³, 7500kg/m³.
N48-N55 grade NdFeB will have a density greater than 7.5g/cm³, 7500kg/m³.
The density of neodymium of N52SH grade is about 7.6g/cm³, 7600kg/m³.
N38EH grade NdFeB density is about 7.65g/cm³, 7650kg/m³.
In NdFeB blank testing, neodymium magnet density is also an important testing index. If the density is low, it may be that the powder does not shrink enough in the material firing process.
Knowledge of neodymium magnets;
Neodymium Magnets vs Ferrite Magnets
How to calculate the weight of neodymium magnets?
How Are Special Shaped Neodymium Magnets Made?
How many hours of neodymium magnet nickel plating salt spray?