What Is A Jig?
Jig is a work holding device that holds supports and locates the workpiece and guides the cutting tool for a specific operation. Often a jig is made of metal which locates and holds the workpiece in a positive manner and also guides the cutting tool such that it is in the correct relationship to the work when the process of machining starts. It is usually necessary for work to be held in the jig by clamping. Jigs are used in unidimensional machining i.e drilling, reaming, counterboring, tapping etc.
Jigs are also used as guides for tools or templates, as in the furniture industry. In furniture industry, special cramping jigs that ensure squareness are set up so that, for example, a wardrobe can be glued up in one operation by power-driven rams.
Types Of Jigs
- Template Jig
- Plate Jig
- Diameter Jig
- Channel Jig
- Ring Jig
- Box Jig
- Leaf Jig
- Angle Plate Jig
- Indexing Jig
- Trunion Jig
What You Need To Know About Jig
- Jig is a work holding device that holds supports and locates the workpiece and guides the cutting tool for a specific operation.
- The main purpose of jigs is to provide repeatability, accuracy and interchangeability in the manufacturing of products.
- Jigs mostly uses standard parts like bushes, screws etc.
- Jig guides the workpiece in machining process.
- Jigs are used in unidimensional machining i.e drilling, reaming, counterboring, tapping etc.
- Jigs are usually not fixed to the table and often come in a portable and compact variant.
- Jigs are lighter in construction for quicker handling and clamping, with the table is often unnecessary.
- No additional device is required for locating the cutter with respect to the workpiece.
- During machining, jigs can be hold in position simple by hands. They may be clamped to machine table for heavier work.
- Jig comes in contact with the cutting tool for it to function. It accurately sets the angle and position for the tool to function.
- The construction and design of the jig is complex to understand.
- Jigs are expensive than fixtures.
What Is A Fixture?
A fixture is a work-holding or support device used in the manufacturing industry. Fixtures are used to securely locate and support the work, ensuring that all parts produced using the fixture will maintain conformity and interchangeability. Using a fixture improves the economy of production by allowing smooth operation and quick transition from part to part, reducing the requirement for skilled labor by simplifying how workpieces are mounted and increasing conformity across a product run.
The primary purpose of a fixture is to securely mount the workpiece in correct position maintaining desired orientation with respect to machine and cutter. A fixture differs from a jig in that when a fixture is used the tool must move relative to the workpiece whereas a jig moves the piece while the tool remains stationary.
Fixtures are used in multidimensional machining i.e milling, planning, slotting, turning, grinding and shaping tools etc. it is also used for assembling and inspection jobs.
Types Of Fixtures
- Plate Fixture
- Angle Plate Fixture
- Vise-jaw Fixture
- Indexing Fixture
- Multistation Fixture
- Profile Fixture
What You Need To Know About Fixture
- Fixture is a work holding device that holds, supports and locates the workpiece for a specific operation but does not guide the cutting tool.
- The primary purpose is to create a secure mounting point for a work-piece, allowing for support during operation and increased accuracy, precision, reliability and interchangeability in manufacturing of products.
- Fixtures are made from grey cast iron or steel parts by welding or bolting.
- Fixture holds the workpiece securely.
- Fixtures are used in multidimensional machining i.e milling, planning, slotting, turning, grinding and shaping tools etc. it is also used for assembling and inspection jobs.
- The fixtures are fixed on the tables for providing the proper support to the workpiece.
- Fixtures are heavier in construction and often bolted rigidly on the machine table.
- Additional accessories like block gauges etc are required to accurately move the cutter in the desired location.
- Fixtures are always rigidly fixed on machine table.
- Fixture never comes in contact with the cutting tool.
- The design and construction of fixture is simple to understand.
- Fixtures cost less than jigs.
Difference Between Jig And Fixture In Tabular Form
| BASIS OF COMPARISON | JIG | FIXTURE |
| Description | Jig is a work holding device that holds supports and locates the workpiece and guides the cutting tool for a specific operation. | Fixture is a work holding device that holds, supports and locates the workpiece for a specific operation but does not guide the cutting tool. |
| Primary Purpose | The main purpose of jigs is to provide repeatability, accuracy and interchangeability in the manufacturing of products. | The primary purpose is to create a secure mounting point for a work-piece, allowing for support during operation and increased accuracy, precision, reliability and interchangeability in manufacturing of products. |
| How It Is Made | Jigs mostly uses standard parts like bushes, screws etc. | Fixtures are made from grey cast iron or steel parts by welding or bolting. |
| Function | Jig guides the workpiece in machining process. | Fixture holds the workpiece securely. |
| Application | Jigs are used in unidimensional machining i.e drilling, reaming, counterboring, tapping etc. | Fixtures are used in multidimensional machining i.e milling, planning, slotting, turning, grinding and shaping tools etc. it is also used for assembling and inspection jobs. |
| Table Fixing | Jigs are usually not fixed to the table and often come in a portable and compact variant. | The fixtures are fixed on the tables for providing the proper support to the workpiece. |
| Weight | Jigs are lighter in construction for quicker handling and clamping, with the table is often unnecessary. | Fixtures are heavier in construction and often bolted rigidly on the machine table. |
| Additional Accessories | No additional device is required for locating the cutter with respect to the workpiece. | Additional accessories like block gauges etc are required to accurately move the cutter in the desired location. |
| Handling | During machining, jigs can be hold in position simple by hands. They may be clamped to machine table for heavier work. | Fixtures are always rigidly fixed on machine table. |
| Contact With Cutting Tool | Jig comes in contact with the cutting tool for it to function. It accurately sets the angle and position for the tool to function. | Fixture never comes in contact with the cutting tool. |
| Design & Construction | The construction and design of the jig is complex to understand. | The design and construction of fixture is simple to understand. |
| Cost | Jigs are expensive than fixtures. | Fixtures cost less than jigs. |
Advantages of Jig And Fixture
- Reduction of overall machining cost and also increases interchangeability.
- Increase productivity and maintenance of product quality consistency.
- To eliminate marking, punching, positioning, alignments etc.
- Accurate locating and clamping the blank in alignment of the cutting tool.
- To reduce cost and measurements.
- Complex and heavy components can be machined quite easily.
- With Jigs and fixtures, there is increased level of accuracy and consistency.
- They enhance rapid production of work due to quick positioning of tool and workpiece.
- Entering workpiece and pulling is very easy
- The direction of motion for making drill is organized and deterministic.
- The latest design of jigs and fixtures does not require high skill in their operation.
- Jig and fixture increase the operator’s safety.