NFE 25 511 Mechanical Zinc Plated Washers Mech Zinc Plated NFE25 511 HV 430-500 refers to a mechanical part that has been plated with zinc according to the NFE25 511 standard. The HV 430-500 designation indicates the hardness of the zinc plating, with a hardness range of 430 to 500 on the Vickers scale. This type of plating is commonly used to provide corrosion resistance and improve the appearance of metal parts. Belleville washers are corrosion-resistant, durable, and can withstand high temperatures, making them suitable for a wide range of industrial and commercial applications.