Lock Washer Lock Washer Type Wedge Lock Finish Delta Protect Material Steel For Screw Size 38 mm Inside Diameter 38.68 mm Outside Diameter 55.8 mm Maximum Thickness 6.5 mm Assembly Thickness 6.5 mm Color Silver Material Grade/Class Case Hardened Pack Size Small Pack Resistance Properties Shock Resistant Vibration Resistant Rockwell Hardness HRC40 System of Measurement Metric Package Quantity 25