maximum opening diameter without reinforcement

例句：

1. 1.The machine has a maximum opening diameter of 50 mm.
   这台机器的最大开口直径为50毫米。
2. 2. The pipe is designed to accommodate the maximum opening diameter of the fittings.
   该管道设计以适应配件的最大开口直径。
3. 3. The drill bit must be aligned with the maximum opening diameter of the hole.
   钻头必须与孔的最大开口直径对齐。