The document discusses the purpose and benefits of using jigs and fixtures in machine shops. It defines jigs and fixtures, noting that jigs guide cutting tools while fixtures hold workpieces. Benefits include increased production, consistency, cost reduction, and safety. Jigs and fixtures are justified for machining like drilling, milling, and grinding, as they improve precision and efficiency. Examples provided include drilling jigs, milling fixtures, and inspection fixtures. Overall, the document outlines how jigs and fixtures improve manufacturing by increasing accuracy and reducing variability and costs.

1. Purpose of Using jigs and Fixtures in
machine shops
Presented by
ARNAB DAS
12000721060
For the partial fulfillment of CA1 for
Manufacturing Technology
PC-ME601
Mechanical Engineering Department
Dr. B. C. Roy Engineering College, Durgapur
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2. Contents
• Introduction
• Definition of Jigs and Fixtures
• Differences between Jigs and Fixtures
• With a suitable example explain the purpose or benefits of using jigs and fixtures in machine shops
• Under what condition of manufacturing by machining, use of fixtures or jigs is justified. Explain with
a specific example
• Summary
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3. INTRODUCTION
• The successful running of any mass production depends upon the interchangeability to facilitate easy assembly and
reduction of unit cost. Mass production methods demand a fast and easy method of positioning work for accurate
operations on it.
Jigs and fixtures are production tools used to accurately manufacture duplicate and interchangeable parts. Jigs and
fixtures are specially designed so that large numbers of components can be machined or assembled identically, and to
ensure interchangeability of components
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• Definition of Jigs
A jig may be defined as a device which holds and located a work piece and guides and controls one or more cutting
tools. The holding of the work and guiding of the tool is such that they are located in true positions relative to each
other.
In construction, a jig comprises a plate, a structure, or box made of metal or in some cases of non-metal having
provisions for handling the components in identical positions one after the other, and then guiding the tool incorrect
positions on the work in accordance with the drawing, specification, or operation layout.
• Definition of Fixtures
A fixture is a device which holds and locates a work piece during an inspection or for a manufacturing operation. The
fixture does not guide the tool.
In construction, the fixture comprises a different standard or specially designed work holding the device which is
clamped on the machine able to hold the work in the position. The tools are set at the required positions on
the work by using gauge or by manual adjustment.
• Differences between Jigs and Fixtures
Jigs Fixtures
Jig is a device primarily used to guide the
cutter to repeatedly move at predefined
locations on the work piece. Jigs can also
hold, support and locate the work piece
apart from guiding the cutter.
Fixture is a device used to rigidly grip,
support and locate the work piece
maintaining intended orientation. It does
not guide the cutter to move to a
particular location.

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Jigs Fixtures
A jig is usually lighter in weight.
Sometimes jigs are hold by hand only
without clamping.
Fixture is commonly heavier and robust
as it is required to sustain the cutting
force and vibration. So it is clamped
firmly with the work table.
Jig is considered easy to use and thus less
skill is required to operate this device.
Fixture is somewhat complicated to use
and thus requires skill.
No additional device is required for
locating the cutter with respect to job.
Additional accessories like blocks, gauges,
etc. are desired to accurately move the
cutter in intended location.
Jig is frequently used in drilling, boring,
reaming and tapping.
Fixture is employed in milling, planing,
shaping, slotting, etc.
Benefits of Jigs and Fixtures
Jigs and Fixtures have made manufacturing processes less time-consuming, more precise, and hassle-free from a human
factor perspective. The benefits of jigs and fixtures include but are not limited to the following:
• With a suitable example explain the purpose or benefits of using jigs and fixtures in machine shops

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• Increase in production
• The consistent quality of manufactured products due to low variability in dimension
• Cost reduction
• Inter-changeability and high accuracy of parts
• Inspection and quality control expenses are significantly reduced
• The decrease in an accident with improved safety standards
• Due to relatively simple maneuverability, semi-skilled workers can operate these tools, reducing the workforce's
cost.
• The machine tool can be automated to a reasonable extent
• Complex, rigid and heavy components can be easily machined
• Simple assembly operations reduce non-productive hours
• Eliminates the need for measuring, punching, positioning, alignments, and setting up for each work piece, thereby
reducing the cycle and setting up a time
• Increases technological capacities of machine tools
• More than one device can be used simultaneously on a work piece
• Setting higher values of some operating conditions like depth of cut, speed, and rate of feed can be attained
because of the increased clamping capability of jigs and fixtures.
• Under what condition of manufacturing by machining, use of fixtures or jigs is
justified.
Jigs and fixtures work to improve the precision of your manufacturing machinery. Using a jig helps with consistency, as the jig
works by guiding the tool in place. While in production, the jig works to control and guide the cutting tool to a precise location
on the work piece. A fixture is a work holding device.
jigs and fixtures are essential tools for the manufacturing industry. The primary use of these tools in internal-machining
applications is for cylindrical and irregular-hole machining

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cylindrical and Irregular-Hole Machining
The appropriate jigs and fixtures for cylindrical and irregular-hole machining applications:
• Drilling jigs
• Boring jigs
• Electrical discharge machining fixtures
• Punching fixtures
• Internal-broaching fixtures
External-Machining Applications
Jigs and fixtures can be used for a variety of external-machining applications, such as:
• Flat-Surface Machining
• Milling fixtures
• Surface-grinding fixtures
• Planing fixtures
• Shaping fixtures
There are also other uses for fixtures in cylindrical-surface and irregular-surface machinery, which are listed below.
Cylindrical-Surface Machining
Having an even and consistent shape is extremely important in all manufacturing products, but especially when working with round
surfaces. For those working with cylindrical surfaces, the best fixtures to use are:
Lathe fixtures
Cylindrical-grinding fixtures
Irregular-Surface Machining
Working with irregularly shaped surfaces can be difficult, especially in mass production facilities with high demands. Increase your
production efficiency with these fixtures designed for irregular-surface applications:
Band-sawing fixtures
External-broaching fixtures

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Non-Machining Applications
Besides working great for internal and external machining operations, jigs and fixtures are suitable for a variety of non-machining
applications.
Assembly
Fixtures being used in assembly offer valuable support to the work piece, allowing the operator to easily complete their job.
Welding fixtures
Mechanical-assembly fixtures (Riveting, stapling, stitching, pinning, etc.)
Soldering fixtures
Inspection
Ensure the quality and safety of each component by using fixtures in the inspection process. Fixtures can assist with inspecting a variety
of equipment, such as:
• Mechanical-inspection fixtures
• Optical-inspection fixtures
• Electronic-inspection fixtures
Finishing
At the end of your manufacturing process, finishes provide the extra appeal to your product. Fixtures for the finishing application are:
• Painting fixtures
• Plating fixtures
• Polishing fixtures
• Lapping fixtures
• Honing fixtures
Miscellaneous Applications
Outside of the above applications, jigs and fixtures can also work with layout templates, testing fixtures, and heat-treating fixtures.

9. Summary
The unit contents description of jigs and fixtures as a clamping tool for work piece and guiding tool
for the tool. Use of jigs and fixture directly influence the quality of performance of the operation. It
improves efficiency of work by eliminating production of poor quality products and reducing the
product cycle time. Design of jigs and fixtures Jigs and Fixtures truly depends on the type of
operation and machine tool to be used for that operation. The use of jig and fixture involve locating
the work piece is right position on the machine tool. The meaning of location is determining the
points on the work where it should be supported to restrain all the motions so that the work can be
done without any problem. Some principles of locations are followed for this purpose like 3-2-1
principle of location, location on a „Vee‟ block, flat locator, cylindrical and conical and jack pin
locators. The major objective of the principle of location is to clamp the rigidity of clamping. At the
same time this all keep the processing area clear and available for processing. Different types of
clamping devices and characteristics of a good clamping device are also described in the unit. Along
with the fixtures jigs are used to guide the tool movement during an operation. These are made of
hardened steel, wear resistant and corrosion resistant steel. Different types are jigs are used for
different types of operations. The commonly used fixtures are also described in the unit. Common
fixtures are milling fixture and welding fixture.
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Reference
All the ideas that I have shown in the upper slides have been searched in books. First I read those
information from different-different book and collected some of it and joined it
Manufacturing Technology:- R.K RAJPUT