countersunk head square neck bolt

例句：

1. 1.The engineer used a countersunk headsquare neck bolt to secure the roof.
   工程师使用一个倒置头的方颈螺栓来固定屋顶。
2. 2. The construction crew was taskedwith installing the countersunk head squareneck bolts.
   建筑工人被指派安装倒置头方颈螺栓。
3. 3. The bolts were designed to be easily removed incase of emergency repairs.
   这些螺栓设计成易于拆卸，以便在紧急维修时使用。