Special Features:

Counterbore center hole to 0.312 in. Diameter by 0.188 in. Deep, countersink corner holes 120 degrees to 0.140 in. Min, 0.170 in. Max diameter @and tap for no. 4-40 screw thd insert

Properties:

An insulator having flat surfaces, with or without holes, whose thickness does not exceed 25 percent of its length or width, whichever is smaller, and whose shape is other than round. Excludes insulator (1), spacer; insulator (1), washer; mounting pad, electrical-electronic component; plate, electrical shield; and terminal board.