... 220mm, Typical Grade:N35,N40,N42,N45,N52,35H,38SH Speaker Neodymium MagnetGrade Available:N35, N38, N40, N42, N45, N48, ... NdFeB are formed by powder metallurgical processes. The magnetic performance of all grades is optimized by applying a magnetic field ... to 1000 times their own weight.• Far better permanent magnetic performance compared with traditional magnets, but the price is relatively ...