Split Lock Washer Lock Washer Type Split Lock Finish Zinc Yellow Material Steel For Screw Size 5/16 in Inside Diameter 0.322 in Outside Diameter 0.583 in Maximum Thickness 0.078 in Minimum Thickness 0.078 in Color Yellow 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