What defines a broach as a cutting tool?

A broach is defined as a cutting tool specifically designed for shaping and enlarging holes due to its unique design and cutting action. It typically consists of a long, tapered piece with multiple cutting edges that progressively remove material as it is pulled or pushed through a workpiece. This makes it highly effective for creating precise and complex shapes, which is particularly useful in machining applications where accuracy is crucial.

In contrast to other cutting tools, like those mentioned in the other choices, which serve different functions or operate on different principles, the defining feature of a broach is its ability to cut through material in a linear motion over a longer length, allowing for smoother finishes and tighter tolerances. Its application is vital in industries such as automotive and manufacturing where precise hole sizes are essential.