This material is hard, brittle and it is easy to get corroded, but in order to protect the surface, we have lots of surface treatment , like Nickel, Nickel-Copper-Nickel, Zinc, Black & Grey epoxy coating, Aluminum coating, Tin, Silver ect coating. It is with high stability even it is under high temperature, the working stability is under 80degreeC for low Hcj,and above 200Degree C for high Hcj.The temperature coefficient s -0.09--0.13% of Brand -0.5--0.8%/degree C of Hcj. Sintered NdFeB magnet offers the highest magnetic properties from 33MGOe to 52MGOe,and we are able to control the magnetic properties within the range as you demanded, like SHT,UHT,L-SHT,EHT such high stable properties could be produced as per your industrial application. Sintered NdFeB magnet are with different grades from N35,N38..N52. From N35SH to N45SH,from N30UH to N40UH,from 30EH to 38EH ,these high Hcj magnets quality are controlled by strip casting and HDDR technology in our factory . * Specification: Any shapes that you designed could be processed, block, disc, segment, ring, horseshoe shape, block with concave holes, disc with countersink etc.Your design will be acted as long as you have. * Application: NdFeB magnet are widely used in important field, you may be interested if you have your project presently: AC,DC,servo motors (with segment magnets). Speaker parts (with ring magnet). Sensors part. Magnetic coupling with segment magnets) Magnetic chuck (with big blocks magnet) Security systems Magnetic separators Filters Brushless motor. Standard Sea and Air package or as per clients's special requirements.