A nut, flat on top and bottom, having 4 flat sides. For items having a thickness (or height) exceeding two times the width across the flats, use post, electrical-mechanical equipment. (when height or thickness and/or width across the flats is designated as a tolerance dimension, the maximum dimension will be used to determine compliance.)
NSN 6220-01-241-4625
NSN 6240-01-210-0164
NSN 5915-01-392-1184
NSN 5925-01-429-0392
NSN 5855-01-535-6275
NSN 6645-00-042-9587
NSN 5950-01-634-0677
NSN 6645-01-411-5657
NSN 6620-00-837-9484
NSN 6650-01-217-0303
NSN 5998-01-316-4312
NSN 5975-00-932-0295