Lock Washer Lock Washer Type External Tooth Lock Finish Plain Material Stainless Steel For Screw Size #4 Inside Diameter 0.123 in Outside Diameter 0.26 in Maximum Thickness 0.018 in Color Silver Dimensional Standards ANSI B18.22.1 For Use With Small Screw Heads Material Grade/Class 410 Pack Size Small Pack Rockwell Hardness C40 System of Measurement Inch Thickness Tolerance 0.012 in to 0.018 in Package Quantity 100