The terms jig and fixture are widely used in the industry to describe auxiliary mechanical devices in the process of assembling, securing, or testing products. Although often used as synonyms, they have distinct technical purposes.
Understanding the difference between jig and fixture is essential for designing efficient and standardized testing or assembly solutions.
🔩 What is a Fixture?
A fixture (or “holding jig”) is a mechanical device designed to hold a piece in position, correctly aligned during a process. It does not contain its own movement and generally does not perform any action, serving as a static support.
🧷 Examples of fixture use:
- Securing a printed circuit board (PCBA) in a holder for manual soldering
- Supporting a component at a specific angle for glue application, laser, or visual inspection
- Positioning a DUT in a standardized way for optical or photographic tests
- Support fittings used in climate test chambers
⚙️ What is a Jig?
A jig is a more complex and functional device, which not only secures but also acts on the piece, usually with moving, electrical, or pneumatic elements. It is commonly used to automate or standardize testing, measurement, or assembly processes.
⚡ Examples of jigs:
- Test jig with pogo pins for electrical contact with the PCB
- Pneumatic jig with automatic DUT activation
- Jig with sensors, actuators, and interfaces for functional tests
- Devices that simulate peripherals during testing (buttons, connectors, cameras, etc.)
🧪 Difference between Fixture and Jig
| Characteristic | Fixture | Jig |
|---|---|---|
| Main function | Support or position a piece | Act on the piece for testing or assembly |
| Movement | Static | Dynamic (pins, actuators, springs, sensors) |
| Complexity | Low | Medium to high |
| Automation | Usually manual | Can be automated (pneumatic, electrical) |
| Common applications | Soldering, inspection, positioning | Electrical and functional tests, automated assembly |
| Cost | Lower | Higher (depending on complexity) |
🏭 How AJOLLY Testing designs jigs and fixtures
At AJOLLY Testing, jigs and fixtures are custom-designed for each industrial application, always focusing on ergonomics, repeatability, quality, and robustness.
- Fixtures developed in acrylic, aluminum, or technical polymer, with laser or CNC cuts
- Jigs integrated with measurement instrumentation, cameras, pressure switches, presence sensors, RFID
- 3D projects with technical documentation, parts list, preventive maintenance, and traceability
- Integration with MES systems, databases, and industrial dashboards
Jigs and fixtures are not just supports — they are strategic tools that ensure quality, repeatability, and productivity on the factory floor.