A jig is a work holding device that locates and guides a cutting tool during machining operations to provide repeatable accuracy. It differs from a fixture which solely holds the workpiece. The document discusses the need for jigs in mass production situations. It provides examples of jig applications and purposes, which include facilitating economical production and interchangeability. The document compares an old jig design to a new proposed design, noting advantages of the new design include easier workpiece binding and a more organized drilling direction. It concludes that jigs are an essential manufacturing element that can increase production rates and reduce costs through consistent part accuracy.

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Introduction to Jig:
It is a work holding device that holds, supports and locates
the work piece and guides the cutting tool for a specific
operation. Jigs are usually fitted with hardened steel
bushings for guiding or other cutting tools. A jig is a type
of tool used to control the location and/or motion of
another tool. Jig is the device which guides the tool,
while fixture is a device that securely holds the job in
position during machining operations. Jig is the partwhich
is used while performing machining operation. Basically,
it provides the guide to the tool. Other thing is fixture
which hold the work piece. Jig is a specific production
device at which hold the work piece strongly or supporting
the work piece and guidance of cutting tool. A jig is often
confused with a fixture; a fixture holds the work in a fixed
location. A device that does both functions holding the
work and guiding a tool is called a jig and fixture.
Need of Jig:
When we require a large number of parts in very short time
then jig is use. A jig is a type of custom-made tool used
for the location and motion of another tool. They
observed that the primary purpose of a jig is to provide repeatability, accuracy, and
interchangeability in the manufacturing of products. Although the most common jigs are the drilling
and boring jigs, they are all identical except for the shape, type, and the position of the bushings for
drilling or boring. Jigs are imparted with tool guiding elements such as drill bushes, which regulate
the tool to the right position in the work piece.
Applications of Jig and fixture:
There are various fields where we can use Jigs and Fixtures and those are:
 Facilitate economical production of engineering components.
 Make operation of parts fairly simple which otherwise would require a lot of skill and time.
 Manufacture accurately 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.
 Mass production of automobile parts.
 Inspection of parts in continuous production in manufacturing industries.
 Cutting the ingots in the steel plant.
 In the refrigeration industry.
 Pump assembling process
 For drilling the flanges and drilling holes to any required angles.
 For multi-spindle machining.

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 Purpose of jig and fixture:
The basic purposes of developing and using suitable jigs and fixtures for batch production in
machine shops. To eliminate marking, punching, positioning, alignments etc. Easy, quick and
consistently accurate locating, supporting and clamping the blank in alignment of the cutting
tool. Guidance to the cutting tool like drill, reamer etc. Increase in productivity and maintain
product quality consistently. To reduce operator’s labour and skill – requirement. To reduce
measurement and its cost. Enhancing technological capacity of the machine tools. Reduction
of overall machining cost and also increases in interchangeability.
Old jig Diagram & Disadvantages :
Old design of jig:
DisadvantagesofOld DesignJig Fixture:
The direction of motion for drilling operation is random. The binding process for
fix guide drill is difficult & it takes a long time. The guide drill fixes the work piece that may
causes bending in the bottom surface. The work piece is compound from two parts which may
result in slipping in the parts of work piece.
Diagramof New design of Jig Fixture:

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 Block:
It is used to support the guide drill.
 Fork block:
It is used to locate the arm with interfacing the work piece.
 Table:
It is used to control the motion of fixture and locate the actual place of drill.
 Base Plate:
It is basic for building of other components and it is connected with table by link.
 Drill Bushing:
It is used for preventing the corrosion for guide drill.
 Bracket:
It is used for help the arm to rotate by joint.
Advantage of New Design:
The blinding process for fix the work piece is very easy because the screw is
included in Arm. The direction of motion for make drill is organized and deterministic. The
total time for make fix work piece and release is short. The entering work piece and pulling is
very easy. The new design is not required high skill and high performance. The new design is
included drill bushing that makes preventive for guide drill from corrosion. By use the lateral
screw that generates lateral force on the center of work piece and then it preventives the
deviation for part of work piece from another.
Conclusion:
Jigs and Fixture is an essential element in Manufacturing Technology. There are several factors you
should consider to make jig and fixtures. By using these you can save a couple of production time. The
design of jigs and fixtures is dependent on the operation type as well as the machine tool to be used
for the operation. They are fabricated with heat-treated steel that are corrosion and wear resistant.It
can be seen that these are very important in manufacturing industries as these devices increase the
production rate as well as reduce the manufacturing cost. By using these, identical parts are
manufactured with greater dimensional accuracy because the jig gives the right direction in tooling
operation. By using these,anuntrained person canalso perform the machining operation without almost

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any loss and save electricity as well. The only drawback is that the manufacturing cost of jig and fixture
is high.
Reference:
https://en.wikipedia.org/wiki/Jig_(tool)
http://www.scribd.com
http://www.sciencedirect.com
link.springer.com
https://learnmechanical.com/jigs-and-fixtures/
https://www.researchgate.net/publication/281006514_The_Design_and_Need_for_Jigs_and_
Fixtures_in_Manufacturing