"Material: Aluminum Alloy QQ-A-250/11, 6061-T6. Dimensions: 1.700 inches in diameter, 0.090 inches thick. Anodic film coating using chromic acid, MIL-A-8625 Type 1 Class 2. Surface roughness: 250 microinches. Features: Central hole with a 0.500 inch diameter. Four holes with diameters ranging from 0.115 to 0.175 inches and countersink (CSK) at an angle of 80 degrees."