Package of 100 5/16 Inch Lock Washers. Mil-Spec, Case Hardened, Cadmium Plated. Aviation quality. Not your typical Chinese pot-metal mush. NSN 5310-00-959-4679. Raytheon p/n 418387-45. Teledyne Continental Engines p/n X202. SPECS: AAUB Hole Diameter 0.317 inches minimum and 0.326 inches maximum ABKV Outside Diameter 0.622 inches maximum ABPX Material Thickness 0.108 inches minimum and 0.118 inches maximum MATT Material Steel comp 1060 overall or steel comp 1561 overall or steel comp 1064 overall or steel comp 1065 overall or steel comp 1566 overall or steel comp 1069 overall or steel comp 1070 overall or steel comp 1074 overall or steel comp 1572 overall or steel comp 1075 overall or steel comp 1078 overall or steel comp 1080 overall MDCL Material Document AND Classification 66 fed std all material responses overall SFTT Surface Treatment Cadmium overall STDC Surface Treatment Document AND Classification QQ-P-416, ty 2, cl 3 fed spec single treatment response overall STYL Style Designator Split helical-right hand ZZZT Nondefinitive Spec/STD Data 4 style and A class 13859 WRD17