What is end milling primarily used for?

End milling is primarily utilized for machining surfaces that can be both parallel and perpendicular to the spindle axis. This versatility is one of the key features of end mills, which have cutting edges on both the end and the periphery, allowing them to engage with the workpiece at various angles. As a result, end milling can effectively produce complex shapes, contours, and a variety of surface finishes, making it suitable for applications that require precision in different orientations.

In contrast, the other options do not capture the full range of capabilities that end milling offers. For example, while end milling can indeed create flat surfaces and deep slots, it is not limited to these functions. Engraving, on the other hand, is not the primary application for end mills, which are designed for more substantial material removal rather than the fine details associated with engraving. Understanding the specific uses of end milling helps in selecting the right tool for various machining tasks in the metalworking industry.