Washers are categorized as follows: Flat washers (Grade C), Large washers (Grades A and C), Extra-large washers (Grade C), Small washers (Grade A), Flat washers (Grade A, chamfered type), High-strength washers for steel structures, Spherical washers, Conical washers, Square bevel washers for I-beams, Square bevel washers for channel steel, Standard spring washers, Light spring washers, Heavy spring washers, Internal tooth locking washers, Internal serrated locking washers, External tooth locking washers, External serrated locking washers, Single-ear locking washers, Double-ear locking washers, External tongue locking washers, and Locking washers for round nuts.
Flat washers are generally used in connections where one component is soft and the other is hard and brittle. Their main function is to increase the contact area, distribute pressure, and prevent damage to the softer component. The basic function of a spring washer is to apply force to the nut after tightening, increasing the friction between the nut and bolt. The material is 65Mn (spring steel), with a heat treatment hardness of HRC44～51HRC, and surface oxidation treatment.
Washers (spring washers), also known as retaining rings, are elastic washers or locking washers used to prevent bolts from loosening. The working principle of a locking washer is very simple. It consists of two washers. The outer side has a radially textured surface, while the inner side has a helical toothed surface. During assembly, the inner helical toothed surfaces face each other, and the outer radially textured surface engages with the contact surfaces at both ends. When the connecting parts are subjected to vibration, causing the bolts to loosen, only the relative misalignment between the inner helical toothed surfaces of the two washers is allowed, generating lifting tension, thereby achieving 100% locking.