Four counteredbored holes, counterbore 0.250 in. Diameter by 0.180 in. Deep, 0.145 in. Min and 0.150 in. Max diameter through on 1.840 in. By 1.840 in. Mtg center; four holes thd, 0.086-56 unc-2b through on 1.240 in. By 1.240 in. Mtg center
Material Specification
Qq-a-225/6 federal specification 1st material response or qq-a-200/3, 2034-t351 federal specification 2nd material response
Surface Treatment Specification
Mil-c-5541 military specification single treatment response