Abstract: The loading feather of phenolic resin nut used in structure of spiral driver is researched by finite element method. And the curve of deformation and stress of the nut is gained. It shows the loading of the whole screw thread is not equal. The last screw thread of the nut is not full and the load on it is the highest, so it is the most dangerous place. Then a reasonable structure is obtained. The loading of the screw thread in this structure is reasonable and the loading at the most dangerous place is decreased obviously.

Key words: Finite element, Loading distribution, Nut, Phenolic resin