Which type of tap is not used for cutting threads?

The type of tap that is not used for cutting threads is the taper tip. Tapered tips are typically used for leading and guiding the tap into the material, allowing for proper alignment as it begins the threading process. While they facilitate the initial engagement of the tap with the material, they do not actually cut threads themselves; instead, they create a conical point that helps to start the thread cutting process.

In contrast, the tapping tap, bottoming tap, and plugging tap are specifically designed for cutting threads. The tapping tap has a uniform diameter and is used for standard threading applications. The bottoming tap features a shorter cutting section, allowing it to cut threads close to the bottom of a blind hole, while the plugging tap, which is slightly more tapered than the tapping tap, is designed to create threads in through holes and is commonly used when precision in thread depth is critical. Each of these taps has a specific function in thread cutting, emphasizing the versatility needed in machine design applications.