Lock Washer Lock Washer Type External Tooth Lock Finish Plain Material Phosphor Bronze For Screw Size 3/8 in Inside Diameter 0.384 in Outside Diameter 0.67 in Maximum Thickness 0.032 in Dimensional Standards ASME B18.21.1 Material Grade/Class Not Graded Pack Size Small Pack Rockwell Hardness C50 System of Measurement Inch Package Quantity 50