Lock Washer Lock Washer Type Wedge Lock Finish Delta Protect Material Steel For Screw Size 1/2 in Inside Diameter 0.51 in Outside Diameter 0.937 in Maximum Thickness 0.166 in Assembly Thickness 0.166 in Color Silver Material Grade/Class Case Hardened Pack Size Small Pack Resistance Properties Shock Resistant Vibration Resistant Rockwell Hardness HRC40 System of Measurement Inch Package Quantity 100