A hexagon nut having a concave face and a concave or slotted top.
NSN 2925-00-167-6763
NSN 5985-01-383-3995
NSN 5915-01-609-0063
NSN 7035-00-193-2269
NSN 5920-00-127-3846
NSN 6620-01-661-0455
NSN 5855-00-466-2309
NSN 7035-01-114-3134
NSN 5910-00-942-9317
NSN 5915-01-004-9002
NSN 5930-01-499-1037
NSN 5950-01-235-6702