Hexagonal dies are used for which of the following purposes?

Hexagonal dies are designed specifically for creating or repairing external threads on cylindrical objects. When it comes to rethreading, these dies effectively reshape or restore worn threads to ensure a proper fit, allowing for better connection and functionality. This process is crucial in maintenance and repairs, particularly when dealing with components that may have damaged threads due to wear and tear.

Using hexagonal dies for cutting new threads is not their primary purpose, as they are typically used in scenarios where threads already exist and need to be revitalized. Additionally, while measuring thread pitch is a necessary task in pipe fitting, it is generally done using thread pitch gauges or calipers rather than the dies themselves, which do not serve that specific function. Aligning pipes is another critical task in pipe fitting but is usually accomplished through the use of alignment tools rather than dies, which are focused on threading operations.

In summary, hexagonal dies are optimal for rethreading applications, helping to extend the lifespan of threaded components and ensuring proper connections.