Which device is used to cut internal threads on a plate?

The device used to cut internal threads on a plate is a pipe tap. A pipe tap is specifically designed to create internal threads, allowing a corresponding pipe or fitting to be screwed into the hole. It achieves this by having cutting edges on its flutes that can remove material from the inside of the hole as it is turned, effectively creating the necessary thread profile for secure fastening.

When using a pipe tap, you must ensure you're matching the tap size with the intended pipe size to ensure both functionality and proper fastening. This tool is commonly employed in plumbing and various metalworking applications, making it essential for anyone working with threaded fittings.

The other devices listed, such as the porta-power, magnetic base drill, and tugger, serve different purposes and are not suitable for cutting internal threads. A porta-power is used for compressing or jacking. A magnetic base drill is primarily for drilling holes in steel and usually does not cut threads. Lastly, a tugger is designed for pulling heavy loads and has no function related to threading. This distinction highlights why a pipe tap is the appropriate choice for creating internal threads on a plate.