... NdFeB 3.patent:patent product 4.usage:metallurgy,mining,electric power,chemicals,etc 1. OVERVIEW OF PERMANENT MAGNETIC LIFTERJQYD series ... disadvantages, such as1. High energy consuming,2. In need of power failure protection,3. Magnetic hysteresis,4. Small unit area attraction,5 ... attraction, so there is no need of power protection. In case of power or circuit failure there is no danger of object drop ...