Al, 2024 tem t351, 0.750 porm 0.002 in. Dia, per qq-a-225/6; compression spring, p/n 757-3937-001 and ball, p/n 309-0019-000 placed in thumbnut, p/n 621-2528-002 four places and secured by retainer insert, p/n 757-3933-001; four 0.128 in. Min, 0.131 in. Max diameter holes on 0.528 in. Min, 0.534 in. Max diameter bolt circle concentric within 0.003 in. Diameter to center hole with 0.328 in. Min, 0.329 in. Max dia, countersunk 88.0 degrees min, 92.0 degrees max to 0.365 in. Min, 0.385 in. Max dia; thumbnut flatted to 0.500 in.; o/a thk 0.437 in.; thumbnut finish anodic coating type i or ii per mil-a-8625