3/4 (20mm) Nord Lock Vibration Proof Lock Washer 19290

The washers are installed cam face to cam face. When tightening the fastener to preload, the teeth penetrate and seat against the joint material and the nut and/or fastener head. When subjected to vibration the interacting cams create a wedge action which prevents the fastener from vibrating loose. Vibration Proof Lock WashersFor Use With Grade 5 & Grade 8 BoltsZinc PlatedMaterial: Carbon Steel Hardness: Through Hardened: Min. 44HRC, Max.