1.Composite:Neodymium,iron boron
2.Certification:ISO9001 & ROHS & SGS
3.Sample free

Speaker permanent magnets:
Grades:N33-N50,N35M-N45M,N33H-N42H,N30SH-N40SH,N28UH-N35UH,N28EH-N35Eh,N30AH-N33AH
Shapes and Sizes:according to customer' requirement
Surface Coating:Zinc-coating,Nickel-Coating,Aurum-coating,Silver-coating,Epoxy-coating,Phosphatsing
ndfeb magnet,  are composed of neodymium, iron, boron and a few transition metals.
These magnets are extremely strong for their small size, metallic in appearance and found in simple shapes such as rings, blocks and discs. 
  Dimension and size: with custom requirement (from 0.1mm to 100mm)
  Coating: Zinc , Ni-Ci-Ni, Nickel, Epoxy,Au, and so on
  shaped : Ring ,Block, Disc, Arc, segment, cylinder, and special size. etc
Attributes of Neodymium
Very high resistance to demagnetization
High energy for size
Good in ambient temperature
Moderately priced
Material is corrosive and should be coated for long term maximum energy output
Low working temperature for heat applications, but higher levels of heat resistance materials are being introduced periodically.
Applications of Neodymium
Magnetic separators, linear actuators, microphone assemblies, servo motors, DC motors (automotive starters), computer rigid disc drives, printers and speakers.
Magnetizing and Handling
Neodymium magnets are very brittle and very strong magnetically. Therefore, it is crucial to handle these magnets with extreme care to avoid personal injury and damage to the magnets. Fingers can be severely pinched between attracting magnets. Magnets can chip if allowed to jump at an attracting object. It is highly recommended that when constructing rare earth magnetic assemblies, they be magnetized after assembly..