... an iron based alloy,,NdFeB type rare earth magnet is much more prone to surface oxidation or ... rust,and elimination.Users should consider magnet coating,plating or suitable surface treatment.5) Less ... than ceramic,higher than SmCo type rare earth magnet.7) Irreversible loss at high temprature.8) ... ,N38M,N40M,N27H,N30H,N33H,N35H,N37H,N27SH,N30SH,N33SH,N35SH,N25UH,N28UH,N30UH,N35SH,N38,N45 ...