镙钉帽

例句：

1. 1. The screw cap fits tightly onto the box.
   螺丝帽紧紧地套在盒子上。
2. 2. The screw head is visible through the hole in the wall.
   螺丝头从墙上的孔中露出来。
3. 3. The screw cap was designed to prevent leaks.
   这个螺丝帽设计用来防止泄漏。