Objects that can be detected by security doors: generally, metals that are easy to conduct electricity, that is, objects that are easily attracted by magnets, such as silicon steel, iron, copper, alloys and other objects. However, if the objects are dispersed, such as powdered metal and linear metal, it is not easy to detect. Metals can be detected with a dollar coin as a standard. If the customer's materials are special, you can ask the samples to be tested. I wonder if I can help you?