What is a fixture in the context of CNC machining?

In CNC machining, a fixture is a specialized device designed to hold and secure the workpiece during the machining process. This ensures that the workpiece remains stationary and properly aligned while various cutting operations are performed. The use of a fixture is crucial for achieving high precision and consistency, as it allows for repeatable setups, particularly when multiple parts are being produced.

A well-designed fixture can accommodate different shapes and sizes of workpieces, thereby facilitating quick changes between different jobs without the need for extensive recalibration. Unlike tools that perform cutting or finishing operations, the primary function of a fixture is to provide stability and support, which allows the cutting tool to operate effectively and safely.

To clarify the other options: polishing tools are utilized to enhance surface finish, coolants serve to minimize heat and reduce friction during machining, and automatic tool changers are mechanisms that facilitate the switching of cutting tools but do not involve securing the workpiece itself. Therefore, defining a fixture as a device that holds the workpiece securely highlights its essential role in the CNC machining process.