Lock Washer, Finish Zinc Plated, Material Steel, For Screw Size 3/4 in, Inside Diameter 0.779 in, Outside Diameter 1.209 in, Maximum Thickness 0.219 in, Minimum Thickness 0.219 in, Color Silver, Material Grade/Class Not Graded, Pack Size Small Pack, Rockwell Hardness C46, Thickness Tolerance +/-0.28 mm, Package Quantity 100 This NORD-LOCK(R) Carbon Steel Lock Washer compresses as the fastener is tightened to securely lock bolt or screw heads into place to prevent counterclockwise rotation from vibration.
eBay