Used on sqh-4b towfish. 10.7mm hole diameter 18.1mm outside diameter 2.2mm material thickness catalog calls this: metric spring - din 127b lock washer split helical-right hand
3b thread class right-hand 20 thread quantity per inch nut, cupped material is a steel alloy; nut is irregularly shaped in that it has a head height of only 0.312" of the total height phosphate manganese surface treated
Used on ldt hatch assembly; w/s: seawolf class ssn. 2b thread class left-hand 12 thread quantity per inch nut, spanner nut shall have a (.375-16unc-2b) center hole; it should have (3x.094) thru equally spaced holes on its side; 3 slots (3x.14) on top equally spacedan d (.25) from each edge
Used on ldt hatch assembly; w/s: seawolf class ssn. 2b thread class right-hand 12 thread quantity per inch nut, spanner nut shall have a (.375-16unc-2b) center hole; it should have 3x.094 thru equally spaced holes on its side