iron screw with square head

例句：

1. 1.The car needs to be fixed because it has a broken iron screw.
   这辆车需要修理，因为它有一个断裂的铁质螺丝。
2. 2.The construction workers used steel screws to fasten the wooden planks together.
   建筑工人使用铁质螺丝将木板固定在一起。
3. 3. The engineer designed a new type of iron screw that can be easily adjusted for different sizes.
   工程师设计了一种新型的铁质螺丝，可以很容易地调整以适应不同尺寸。