螺纹底

【机】 bottom of thread

螺纹的英语翻译：

screw thread; whorl; worm
【机】 screw thread; thread

底的英语翻译：

a copy kept as a record; base; bottom; end; fundus; the truth of a matter
【医】 base; basement; bases; basi-; basio-; basis; batho-; bathy-; fimdi
floor; fundus; pavimentum; solum