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Flat washers are mainly stamped out of iron plates. They are usually thin parts of various shapes,such as round, square. The shape is generally a flat washer with a hole in the middle. The size of this hole is generally determined according to customer requirements. DIN125 flat washers are used to reduce friction, prevent leakage, isolate, prevent loosening or disperse pressure. Restricted by the material and process of threaded fasteners, the bearing surface of bolts nuts is not large,