self-tightening mandrel自紧心轴
self-tightening locknut自紧防松螺母
self-tightening seal[机] 自紧密封
self-tightening screw自紧螺钉
self-tightening drill chuck自紧式钻夹头
self-tightening lever clip自紧式夹杆
self-tightening oil seal自紧油封
skeleton type self-tightening oil seal骨架式自紧油封;扇骨子式自紧油封