An item generally round in shape and usually having a centrally located hole. It has at least one flat bearing surface. It is made of precious or semi-precious gem (ruby, sapphire and the like), natural or synthetic. It is intended for use in precision instruments, meters, timing devices, clocks, and the like.
to 5n11-2-11-33 reference data and literature, aircraft mechanical clock abu-11/a 6645-00-076-3050 end item identification, used with jewel and setting assy 200880 and pillar plate assy 400193 special features, jewel,train part name assigned by controlling agency