What type of milling machine moves only along a horizontal axis and mills large, flat workpieces?

The bed-type milling machine is designed specifically for milling large, flat workpieces by moving only along a horizontal axis. This design includes a long, horizontal bed that supports the workpiece, allowing the cutting tool to make precise, straight cuts across the surface. This type of machine is ideal for high-volume production where larger parts need to be machined efficiently.

Vertical milling machines, while versatile and effective for various milling tasks, typically have the spindle oriented vertically and may not be as specialized for large, flat workpieces as bed-type machines. CNC milling machines can perform various tasks but encompass a wider range of capabilities beyond just horizontal movement. Surface grinders, on the other hand, are primarily used for grinding surfaces rather than milling, making them unsuitable for this specific application.

Thus, the characteristics and operational focus of the bed-type milling machine make it the correct choice for milling large, flat workpieces along a horizontal axis.