What is the key difference between a jig and a fixture?

The distinction between a jig and a fixture primarily revolves around their functions in machining and assembly processes. A jig is designed specifically to guide the cutting tool during operations, ensuring precision in the location and angle of the cut. This guidance function helps maintain the accuracy of the workpiece, which is essential for high-quality assembly and manufacturing.

On the other hand, a fixture's primary role is to securely hold and support a workpiece in a specific position during machining or assembly. While fixtures may help in aligning components, they do not provide guidance for a cutting tool, which is the defining feature of a jig.

Understanding this difference is crucial for aerospace assembly mechanics, as selecting the appropriate tool affects the efficiency and quality of assembly processes. The statement about the jig’s ability to guide a cutting tool highlights its unique functionality, thus making it the key distinction from fixtures, which serve a different purpose.