1)right-and-left threaded,正反螺纹的2)incorrect thread,不正确的螺纹线3)threadthreaded,螺纹螺纹的4)left handed nut,反螺纹螺帽5)back whorl,反螺纹6)the whorls of a fingerprint,指纹的螺纹
用法和例句
The organic clay and the pellet of nylon6 are blended with certain ratio in twin screw extruder with back whorl .