Aluminum, qq-a-250/4, 2024-t351 bare; 1.560 in. O/a lg; 1.100 in. O/a w; 0.590 in. O/a thk; one 0.190 in. Min, 0.196 in. Max diameter hole through thk; 7/16-20 unf 3a thd opening, 0.169 in. Min, 0.175 in. Max diameter thd opening; lower edges chamfered 0.240 in. By 45 deg