China Neodymium And Ferrite Magnets Manufacturer & Supplier 
Both Y40 and Y35 are ferrite grade designations. When selecting ferrite magnets, many customers often encounter this question: How much difference is there between Y40 and Y35? Is it worth spending extra to upgrade? As a professional magnet manufacturer, we use actual test data and application examples to help you fully understand the differences between these two grades.
From the ferrite magnetic property grade data sheet, we can extract the following typical magnetic property data for two grades: Y35 has a remanence Br of 430–450 mT and a maximum energy product of 33.1–33.2 kJ/m³. Y40 has a remanence Br of 450–460 mT and a maximum energy product of 37.6–41.8 kJ/m³.
Illustration shows Y35 ferrite block magnets
Regarding remanence (Br), the lower limit for Y40 is approximately 450 mT, while the upper limit for Y35 is about 450 mT. The difference between the two is only a few mT (roughly 0.5%-2%), indicating a modest improvement in remanence. Regarding maximum energy product, Y40 ranges from 37.6 to 41.8 kJ/m³, while Y35 ranges around 33.1 to 33.2 kJ/m³. Calculated at the median value, Y40 achieves approximately a 16% increase over Y35 in (BH)ₘₐₓ.
However, the actual “magnetic force output” is also influenced by factors such as size, shape, gap, and the installed magnetic circuit. Therefore, it is not accurate to simply state that Y40 is 15% or 20% stronger than Y35 while ignoring other variables.
For example, a 10x3mm circular ferrite magnet with a Y35 grade exhibits a pull force of 0.28kg, while a Y40 grade may increase this to 0.32kg—representing an approximate 14% improvement.
What applications is Y40 suitable for?
It is suitable for space-constrained applications requiring performance upgrades, such as established products like motors, speakers, and industrial fans where magnet installation space cannot be expanded but a 10-20% performance boost is needed.
How much more expensive is Y40 compared to Y35?
Raw material costs are approximately 10-15% higher, and the unit price for bulk purchases is about 8-12% higher. Specific pricing depends on purchase volume, dimensional accuracy, processing complexity, and other factors.
Can Y40 replace neodymium magnets?
It can in some scenarios but with limitations. For instance, it cannot replace neodymium in applications requiring extremely high power density, severely constrained space, or high-precision servo systems. However, it is suitable for scenarios where magnetic force requirements are less stringent and larger installation spaces are permissible.
The above covers how much stronger ferrite Y40 magnets are compared to Y35. For applications requiring increased magnetic energy output, higher power density, or reduced magnet size, selecting Y40 is beneficial. If cost sensitivity is a priority, Y30 or Y35 remain viable options.
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