原子筆通常呈圓形,中心通常有一個孔。它至少有一個平坦的承重面。它由天然或合成的珍貴或半珍貴寶石(紅寶石、藍寶石等)製成。它適用於精密儀器、儀表、計時裝置、鐘錶等。
to 5n11-2-11-33 reference data and literature, jewel,train part name assigned by controlling agency, used with jewel and setting assy 200880 and pillar plate assy 400193 special features, aircraft mechanical clock abu-11/a 6645-00-076-3050 end item identification