What is the difference between a jig and a fixture in manufacturing?

The primary difference between a jig and a fixture is whether the device actively guides the cutting tool during machining. A jig holds and locates the workpiece while incorporating hardened bushings, templates, or physical guides that steer manual cutting tools, such as drill bits or reamers, directly to the correct coordinate. Jigs are predominantly utilized in manual drilling, boring, and tapping operations where the machine lacks automated positioning control.

A fixture securely locates, supports, and clamps the workpiece in a fixed coordinate system relative to the machine table, but it does not guide the cutting tool. Instead, modern CNC machines rely on programmed spindle coordinates, linear glass scales, and rigid axis drives to direct the toolpath. In CNC milling, turning, and grinding, modular fixtures equipped with vises, chucks, or pallets locate the raw material using drawbars, spigots, or pull studs, leaving the spindle free to access features without mechanical tool guidance.