Available Coating of Sintered Neodymium Magnets

Surface	Coating	Thickness(um)	Color	SST(Hours)	PCT(Hours)
Nickel	Ni+Ni	10-20	Bright Silver	24-72	24-72
	Ni+Cu+Ni
Black Nickel	Ni+Cu+Ni	10-20	Bright black	48-96	>48
Cr3+Zinc	Zn	5-8	Bright Blue	16-48	Not Applicable
	C-Zn		Shining Color	36-72
Sn	Ni+Cu+Ni+Sn	10-25	Silver	36-72	>48
Au	Ni+Cu+Ni+Au	10-15	Gold	>12	>48
Ag	Ni+Cu+Ni+Ag	10-15	Silver	>12	>48
Epoxy	Epoxy	10-20	Black,Grey	>48	Not Applicable
	Ni+Cu+Epoxy	15-30		72-108
	Zn+Epoxy	15-25		72-108
Passivation		1-3	Dark Grey	Temporary Protection	Not Applicable
Phosphated		1-3	Dark Grey	Temporary Protection	Not Applicable

Note:

1. The salt spray test result of grinding coating is better than hanging up coating.
2. SST Test Condition: 5% NaCl, 35oC, continuously spayed for a certain time
3. Pressure Cooking Test (PCT) Test Condition: 2 atm, 95% RH (relative humidity), 121^oC
4. Other Testing Methods: Drop Test, Cross Cut Test, Heating and Spilling Test, Constant Temperature and Humidity Test, etc.

Neodymium Magnets Technical Sheet From Stanford Magnets.