Which CNC mill workholding device has one fixed and one moveable jaw to hold simple workpieces?

Which CNC mill workholding device has one fixed and one moveable jaw to hold simple workpieces?

• A. Vise
• B. Chuck
• C. Clamp
• D. Fixture

Answer: (A)

Holding a simple workpiece on a CNC mill is best done with a vise. A milling vise has one fixed jaw and one movable jaw, with the workpiece placed between them and the movable jaw tightened by a screw to apply even clamping pressure. The fixed jaw provides a solid reference surface, while the movable jaw closes in to grip the stock securely, keeping it square to the machine table and aligned for accurate milling. This setup is quick, repeatable, and ideal for flat, simple parts. Chucks are designed to grip round or irregular shapes on a rotating spindle with multiple jaws that move in concert, which isn’t the straightforward two-jaw arrangement described here. A clamp is a general holding method and doesn’t inherently provide the two-jaw, fixed-plus-movable system. A fixture is a custom, often more complex holding assembly with locators and multiple clamps, used for high-volume or specialized setups. So for holding simple workpieces with a reliable, parallel grip, the vise is the right choice.

Holding a simple workpiece on a CNC mill is best done with a vise. A milling vise has one fixed jaw and one movable jaw, with the workpiece placed between them and the movable jaw tightened by a screw to apply even clamping pressure. The fixed jaw provides a solid reference surface, while the movable jaw closes in to grip the stock securely, keeping it square to the machine table and aligned for accurate milling. This setup is quick, repeatable, and ideal for flat, simple parts.

Chucks are designed to grip round or irregular shapes on a rotating spindle with multiple jaws that move in concert, which isn’t the straightforward two-jaw arrangement described here. A clamp is a general holding method and doesn’t inherently provide the two-jaw, fixed-plus-movable system. A fixture is a custom, often more complex holding assembly with locators and multiple clamps, used for high-volume or specialized setups. So for holding simple workpieces with a reliable, parallel grip, the vise is the right choice.