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 6135-01-120-9812
NSN 6130-01-418-0786
NSN 6685-01-462-1770
NSN 5895-01-515-9137
NSN 6645-01-591-3970
NSN 5998-01-501-8671
NSN 5975-00-472-7778
NSN 6320-01-578-6006
NSN 5998-00-835-7261
NSN 5998-00-133-2589
NSN 5990-01-189-9338
NSN 5950-00-222-1413