China Neodymium And Ferrite Magnets Manufacturer & Supplier 
The 40mm neodymium magnet is a medium-sized magnet primarily used in various machinery, hardware components, salvage operations, magnetic levitation, magnetic bases, and similar applications. If you're seeking information about its magnetic strength, this article will be helpful.
Regardless of the material, when discussing magnetic strength, we must understand the factors that influence it. The most direct factors are performance grade and thickness. For neodymium magnets, the higher the number, the stronger the magnetic properties. For example, two magnets with the same 40mm diameter and 5mm thickness will exhibit significantly greater magnetic pull in an N54 grade compared to an N35 grade. Regarding thickness, a thicker magnet has a larger volume, concentrating magnetic flux more intensely and resulting in stronger magnetic pull.
The image shows 40mm length block magnet with two countersunk holes.
Reference for 40mm Neodymium Magnet Pull Strength;
Ø40 x 10mm neodymium disc magnet, maximum pull strength approximately 20kg.
Ø40 x Ø19mm x 7mm standard grade neodymium ring magnet, maximum pull strength approximately 18kg.
F40 x 11 x 6mm neodymium block magnet, maximum pull strength approximately 9.5kg.
Due to the extremely strong magnetic force of 40mm neodymium magnets, caution is required during use. When separating two magnets that are stuck together, employ a sliding motion to avoid pinching your fingers.
The above details the magnetic strength of 40mm neodymium magnets. Regardless of thickness, these magnets exhibit exceptionally strong magnetic properties. Particularly when exceeding 10mm in thickness and reaching the N52 grade, their magnetic pull can easily surpass tens of kilograms.
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