These washers have cams or wedges on one side, with a lead angle greater than a thread angle and radial teeth or ribs on the other. The washers are installed from side to cam surface. When tightening the fastener for pre-tensioning, the teeth penetrate and sit against the joint material and the nut and/or the fixing head. In case of vibration, the interacting cams create a wedge movement that prevents the shutter from vibrating loosely.
Nord Lock Vibration-resistant locking washers.
For use with grade 5 and class 8 screws.
Zinc Plated
Material: Carbon Steel
Hardness: Hardened: min. 44HRC, max. 51HRC
Screw Size: 1/4" 6mm
O.D. : 27/64?
50 (25 pairs) per pack.