Which tool is specifically designed for sawing metal?

The tool specifically designed for sawing metal is a hacksaw. A hacksaw features a fine-toothed blade that is tensioned in a frame, allowing it to cut through various types of metal with precision. The design of the blade, combined with its ability to accommodate different blade types, makes it ideal for cutting materials like steel, aluminum, and other metals.

In contrast, the other tools listed serve different purposes. For instance, a hammer drill is primarily used for drilling into hard materials such as concrete and masonry, involving a hammering action that is not suitable for cutting metal. A half round file is a shaping tool that smooths or shapes materials, but it is not designed for sawing; it is used to refine edges or surfaces rather than to make cuts through solid mediums. Hedge shears are gardening tools intended for trimming hedges and shrubs, clearly unsuitable for working with metal. Hence, the hacksaw is the correct choice for metal sawing due to its specific design and function.