2020.5.29
Fixtures and jigs are both used to reduce the non-production time of mass production process and are often used as synonyms for each other. Functionally, they are different tools. Then what’s the difference between jig and fixture? Fixture vs jig, take a look at the comparison involves the definition, types, applications, the way of working, purposes and more aspects.
Jig is a type of custom-made work holding device used to control the location and motion of parts and other tools, in CNC machining process, a jig often locates and holds the workpiece in a proper position and guides the cutting tool to do a specific operation, to maintain correct relationship between the work and cutter. When the jig moves, the tool remains stationary. The machining part usually is secured in the jig by clamping.
The most common type of jig is drill jig, which used to guide the drill bit for producing holes at specific locations, Examples of drill jigs are box jig, angle plate jig, sandwich jig, and channel jig. Wood working jigs are also widely used for creating intricate wooden profiles. There are also other types of jigs including template jig, plate jig, diameter jig, ring jig, indexing jig, welding jig, jeweler jig, and more.
Jigs are often used in drilling, reaming, counterboring, tapping and other one-dimensional machining, or applied as guides for tools or templates in other industries, like furniture, special cramping jigs that ensure squareness are often set up. Drill bushing is another common application for jig, which helps guide a drill bit through the surface of machining part for right positioning and angle.
Fixture is a work holding device used to securely locate, support and mount the part to be machined with the machine in correct position, to make sure the workpiece fixed in the fixture can maintain conformity and interchangeability. When the fixture moves, the tool moves relative to the part. Fixtures can ensure the part is stable, simplify the mounting of workpiece, so as to realize quick transition from part to part and smooth operation. What fixture differs from jig is it never guide the tool.
Based on the operation to be carried out, fixtures can be divided into turning fixtures, milling fixtures, grinding fixtures, broaching fixtures, drilling fixtures, tapping fixtures, welding fixtures, and assembling fixtures.
Fixtures are often used in milling, turning, planning, slotting, grinding, and other multidimensional machining processes, as well as automobile assembling and optical, laser scanning inspection. The material block clamped inside a CNC machine, the vice on workbench is also a fixture. Fixtures are also essential in an automobile assembly line to secure and guide cars through the welding and assembly process.
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.
CNC machining service is a versatile manufacturing process to produce jigs and fixtures with designed shapes and specification. Not all jigs and fixtures are made of metals, plastics are also possible. CNCLATHING OEM CNC manufacturing can maintain high precision and standard tolerance.