Packing Nut

An item having internal and/or external machine threa (s) (threads other than pipe or hose series), specifically designed to retain, by means or groove(s), shoulder(s) , and the like, packing and/or a packing gland within a stuffing box. See also bushing, machine thread; inverted nut, tube coupling; and nut, tube coupling. Excludes packing nut, stuffing tube; and use with electrical cable, and locknut, pipe.