cap of screw

例句：

1. 1.The screw cap on the box is loose.
   盒子上的螺丝帽松动了。
2. 2. The screw cap was used to secure the lid.
   螺丝帽被用来固定盖子。
3. 3. The screw cap was removed to replace the damaged part.
   螺丝帽被移除以更换损坏的部分。