Both jigs and fixtures used for machine tool can reduce work time and improve the productivity. Fixture vs jig, what are the differences between fixture and jig?
1. Main Function
Jig is primarily used to guide the movement of cutter repeatedly at predefined locations on the work, and support and locate the part as well. Fixture is mainly used to secure, support and locate the workpiece and maintain predetermined orientation, not guide the cutter.
2. Complexity
Jigs are generally easier to use, while fixtures is kind of complicated and may need some skills and accessories for the operation.
3. Weight
Jigs are often lighter in weight for quicker handling, while fixtures are usually heavier and required to withstand cutting force and vibration
4. Whether fitted to machine
Jigs are not fixed to the table, and can be held by hand without clamping in machining, they can also be clamped for heavy work, and it does not need any additional devices, while fixtures are always clamped firmly on the work table of CNC machine, and requires accessories like blocks or gauges to move the cutting tool accurately.
5. CNC machining applications
Jigs are commonly used in drilling, boring, reaming and tapping, while fixtures are adopted for milling, slotting, shaping, turning and planning.
6. Cost
Jigs are usually more expensive than fixtures.
7. Design
The construction of the jig is often designed more complex while the fixture designs are simpler.
8. Whether contact with cutting tool
Fixtures does not directly contact with a cutting tool, it’s designed to fit a certain part individually. But jig come in contact with the tool to set the angle and position accurately.
9. How it is used
Fixtures are usually made from gray cast iron or steel parts by welding or bolting, jigs generally uses standard parts like bushes and screws.
You can use jigs and fixtures together to get required precision and purpose. We can see the fixture and jig difference in construction directly from the following figure. The left one is jig as it has hole to guide tool, while the right u-shape body is fixture as it is just holding the workpiece.