Lock Washer, Finish Zinc Plated, Material Steel, For Screw Size 20 mm, Inside Diameter 20.7 mm, Outside Diameter 30.7 mm, Maximum Thickness 6.01 mm, Minimum Thickness 6.01 mm, Color Silver, Material Grade/Class Not Graded, Pack Size Small Pack, Rockwell Hardness C46, Thickness Tolerance +/-0.32 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.
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