filetage NC à gros pas

OBS: Série à filets gros : Pour pièces et équipement ordinaires dans l'industrie et le commerce.
OBS: ""UNC""=""Unified coarse thread"" (gros pas).

CONT: Unified and American National screw thread standards for screws, bolts, nuts, and other threaded parts consist of six series of threads and a selection of special threads that cover nonstandard combinations of diameter and pitch. In general, the unified screw threads are limited to three series: coarse (UNC), fine (UNF), and extrafine (UNEF). A 1/4-inch-diameter thread in the UNC series has 20 threads/in., while in the UNF series it has 28. In the Unified and American National standards, the coarse thread series (UNC and NC) is recommended for general industrial use on threaded machine parts and for screws and bolts. Because a coarse thread has fewer threads per inch than a fine thread of the same diameter, the helix angle is greater, and the thread travels farther in one turn. A coarse thread is preferred when rapidity and ease of assembly are desired, and where strength and clamping power are not of prime importance.