Jigs and fixtures, despite the mere difference of a single letter, are often confused and sometimes misused. So, what exactly distinguishes a test fixture from a jig? Let Silman Tech elaborate on this in detail.
- Concept of Jigs: A jig is a category of tools used in woodworking, metalworking, carpentry, machinery, electronics, and various other manual crafts. It is primarily used to coordinate and control specific positions or actions (or both). The term “jig” was influenced by the long-term Japanese administration in Taiwan.
Types of Jigs: Jigs can be classified into three main categories: process assembly jigs, project testing jigs, and PCB testing jigs. Process assembly jigs include assembly, welding, disassembly, dispensing, exposure, adjustment, and cutting jigs. Project testing jigs include life testing, packaging testing, environmental testing, optical testing, shielding testing, and sound insulation testing jigs. PCB testing jigs mainly consist of ICT testing, FCT functional testing, SMT reflow testing, and BGA testing jigs.
Primary Uses of Jigs: Jigs are formed in response to industry needs, including mechanical, woodworking, welding, jewelry, and other fields. Some types of jigs are also referred to as “molds” or “accessories,” with their key significance lying in replicating specific parts with repeatability and accuracy. Many types of jigs are customized, aiming to enhance productivity or precision in operations.
Distinguishing Between Jigs and Fixtures
- Concept of Fixtures: Universally, any device used in the process to quickly, conveniently, and safely install workpieces can be termed a fixture. Examples include welding fixtures, inspection fixtures, assembly fixtures, and machine tool fixtures. Machine tool fixtures, in particular, are more common and are often simply referred to as fixtures. When machining workpieces on machine tools, it is necessary to securely position and clamp the workpieces to achieve the technical requirements of size, geometric shape, and positional accuracy specified in the drawings.
Types of Fixtures: Fixtures can be categorized based on their application characteristics into universal fixtures, specialized fixtures, adjustable fixtures, combination fixtures, etc.
Difference Between Test Jigs and Fixtures: In summary, although both serve similar primary purposes, jigs are primarily used as guiding tools, while fixtures are primarily used for holding tools in a fixed specific position. Some devices that perform both functions (guiding and holding tools) are also called jigs, but devices that only hold without guiding are referred to as “fixtures” rather than “jigs.” The application of jigs has decreased with the advent of CNC systems.