Which of the following is a common workholding device used in milling?

In milling operations, a vise is a commonly used workholding device because it securely holds the workpiece in place while the cutting tool performs its operation. The design of a milling vise typically includes parallel jaws that can be adjusted to accommodate different sizes and shapes of workpieces. This stability is crucial for achieving precise cuts and maintaining accuracy during the milling process.

The vise effectively immobilizes the workpiece, preventing any movement that could lead to inaccuracies or defects in the milling operation. It is especially useful for holding flat, rectangular workpieces, which are often processed in milling applications. The versatility and ease of use of a vise make it an essential tool for machinists in various milling tasks.

In contrast, other devices listed, such as a chuck and a tool holder, serve different functions in machining setups. A boring bar is primarily used for enlarging or finishing holes rather than holding workpieces. Understanding the specific roles of these tools helps clarify why a vise is the appropriate choice for workholding in milling.