Plastic mil-m-20693 or l-p-410
A nonmetallic unthreaded item generally round in cross-sectional shape which, when placed on/in a machined-out portion of the threads of a screw or bolt, or inserted into the machined-out portion of the threads of a nut, locks the item, to which it is fixed, to the attached mating member and prevents loosening during excessive vibration. Excludes bolt, self-locking; nut, self-locking (as modified); screw, self-locking; and insert, screw thread.
NSN 5935-00-204-9909
NSN 5950-01-345-2968
NSN 6105-00-515-3364
NSN 5985-00-594-2107
NSN 6320-01-212-8749
NSN 5835-01-525-3220
NSN 6150-00-428-6494
NSN 5925-01-419-9833
NSN 5999-01-455-4592
NSN 6320-01-116-9866
NSN 6105-01-384-3687
NSN 6135-00-816-9052