flattening machine

例句：

1. 1. This flattening machine is very efficient at removing the outer layer of a sheet of metal.
   这台压平机在去除金属板材的外层方面非常高效。
2. 2. The engineer used this flattening machine to smooth the surface of the newly welded metal.
   工程师使用这台压平机来平滑新焊接的金属表面。
3. 3. The flattening machine was used to create a uniform thickness throughout the sheet.
   压平机被用来在整个板材上均匀地制造厚度。