This specification covers the general requirements for nylon stuffing tubes and packing assemblies. Nylon stuffing tubes are intended for making electric cable penetrations in marine shipboard enclosures for electrical equipment. The following types are suitable for thin-wall enclosures up to a certain thickness and thick-wall enclosures, bulkheads, and decks of also of a certain thickness. Nylon stuffing tubes shall be classified into four types: Type 1 with straight, unified form thread, Type 2 with 90°, unified form thread, Type 3 with NPT, American standard pipe thread and Type 4 with Y, unified form thread. Materials used for the manufacture of these stuffing tubes and packing assemblies shall include polyamide or nylon and synthetic rubber or neoprene. The sizes and dimensions of stuffing tubes and packing assemblies are completely described. In order determine properties such as vibration resistance, ruggedness, and seal effectiveness of stuffing tubes, the following tests shall be performed: vibration test, mechanical abuse test, and level of effectiveness test. In terms of physical appearance, stuffing tubes shall be free from warp, cracks, chipped edges or surfaces, blisters, uneven surfaces, scratches, dents, and heat marks. They shall be free from fins, burrs, and unsightly finish caused by chipping, filing, or grinding without subsequent buffing or polishing. All molded nylon parts shall be cleaned thoroughly of annealing mediums. Packing assemblies shall be free of voids, pin holes, flash, or other imperfections, that may impair their serviceability.