Spring washers, which have axial flexibility and are used to prevent fastening or loosening due to vibrations. This type of washer can be used, that supposed prevent losing and spring action and edge that digs into the screw-on the reverse. Locking washers, which prevent fastening or loosening by preventing unscrewing rotation of the fastening device; locking washers are usually also spring washers. A spring washer assembly is placed under the nut to prevent the loosening of the nut. Spring washers are used for loosening. Spring washers add tension to a fastener assembly and are used to absorb a shock or vibrations.
Lock washers are designed to be tightened to a required torque beneath an ordinary fastener. They exert a spring tension that keeps the fastener from vibrating loose. They are often attached to the nut side of the fastener.