Cage 3s597 does not sell to the government
A nut having 6 flat sides and an integral washer which extends beyond the flats or periphery.
NSN 4140-00-353-5757
NSN 6240-01-347-5476
NSN 5999-01-177-5413
NSN 5998-01-237-3750
NSN 5895-00-244-0943
NSN 6145-00-017-9707
NSN 5965-01-617-4148
NSN 5925-01-374-1489
NSN 6220-01-167-7859
NSN 6320-01-513-9166
NSN 6150-01-451-4810
NSN 5895-00-799-3221