Product Name: Big Ring Ferrite Magnets/Big Round Ferrite Ring Magnets Model NO.: N35-N54( M, H, Sh, Uh, Eh, Ah ) Grade: N35-N54( M, H, Sh, Uh, Eh, Ah ) Coating: Nickel Shape: Ring Application: Speaker Magnet, Industrial Magnet, Jewelry Magnet, Solenoid, Motor Magnet, Magnetic Toy Size: Custom-Make Welcome Tolerance: +/-0.03mm to +/-0.15mm Certificate: SGS, RoHS, Reach,etc Quality System: TUV:Ts16949,ISO9001:2000,etc Working Temperature: 80 to 230 Factory: Over 20 Years Experiences Trademark: XILAMA Transport Package: Antimagnetic Packaging / Neutral Packing Specification: Customized Origin: Jiangmen, China HS Code: 85051110 Product Description DescriptionThe ferrite magnets are mainly formed of Fe2O3(iron oxide) BaCO3(barium carbonate) or SrCO3(strontium carbonate) metal powder. There are two types of magnets: Isotropic Magnet, Anisotropic Magnet. And The Anisotropic Magnet are also divided into dry and wet.Magnets need mold manufacturing. For general magnet specifications, molds have alreadly been made for production.If you need special shape, please inform us beforehand for the time of making mould.Magnet is a hard sintered product that is economical and durable. The finished product is subject to shape. Residual flux density is based on size and shape.Before design,it must know the size ratio, magnetic direction and other information firstly.