One bearing surface has concave shape to threads
No other part numbers with same form, fit, and function found.
A nut, round in shape, having all or part of its outer surface knurled. It may have provisions for external wrenching. For items having a thickness (or height) exceeding two times the outside diameter, use post, electrical-mechanical equipment. See also nut (1), plain, round. (when height or thickness, and/or outside diameter is designated as a tolerance dimension, the maximum dimension will be used to determine compliance).
Classification: Nuts of iron or steel
NSN 2925-01-500-4952
NSN 5920-00-465-0594
NSN 6145-01-564-1521
NSN 5975-00-606-4298
NSN 6240-00-456-2578
NSN 6220-01-093-6723
NSN 5915-01-230-5993
NSN 5998-00-796-7521
NSN 6150-00-067-5244
NSN 5975-01-008-7403
NSN 2925-00-422-5159
NSN 6110-01-519-9131