Split Lock Washer, Lock Washer Type Split Lock, Finish Zinc Plated, Material Steel, For Screw Size #4, Inside Diameter 0.114 in, Outside Diameter 0.209 in, Maximum Thickness 0.025 in, Minimum Thickness 0.025 in, Color Silver, Dimensional Standards ASME B18.21.1, Inside Diameter Tolerance +/-0.005 in, Made in North America No, Manufacturer Location Globally Sourced, Material Grade/Class Not Graded, Material Quality Standards ASTM A307A, SAE J429, Maximum Temperature 275 Degrees F Split lock washers apply greater bolt tension per unit of applied torque to help prevent rotation and loosening. Meet ASME B18.21.1 standards.