Basic Manufacturing Processes and Workshop Technology
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Manufacturing is the backbone of any industrialized nation. Manufacturing and technical staff
in industry must know the various manufacturing processes, materials being processed, tools
and equipments for manufacturing different components or products with optimal process
plan using proper precautions and specified safety rules to avoid accidents. Beside above, all
kinds of the future engineers must know the basic requirements of workshop activities in
term of man, machine, material, methods, money and other infrastructure facilities needed
to be positioned properly for optimal shop layouts or plant layout and other support services
effectively adjusted or located in the industry or plant within a well planned manufacturing
The complete understanding of basic manufacturing processes and workshop technology
is highly difficult for any one to claim expertise over it. The study deals with several aspects
of workshops practices also for imparting the basic working knowledge of the different
engineering materials, tools, equipments, manufacturing processes, basic concepts of electromechanical
controls of machine tools, production criteria’s, characteristics and uses of various
testing instruments and measuring or inspecting devices for checking components or products
manufactured in various manufacturing shops in an industrial environment. It also describes
and demonstrates the use of different hand tools (measuring, marking, holding and supporting
tools, cutting etc.), equipments, machinery and various methods of manufacturing that facilitate
shaping or forming the different existing raw materials into suitable usable forms. It deals
with the study of industrial environment which involves the practical knowledge in the area
of ferrous and non ferrous materials, their properties and uses. It should provide the knowledge
of basic workshop processes namely bench work and fitting, sheet metal, carpentry, pattern
making, mould making, foundry, smithy, forging, metal working and heat treatment, welding,
fastening, machine shop, surface finishing and coatings, assembling inspection and quality
control. It emphasizes on basic knowledge regarding composition, properties and uses of
different raw materials, various production processes, replacement of or improvement over
a large number of old processes, new and compact designs, better accuracy in dimensions,
quicker methods of production, better surface finishes, more alternatives to the existing
materials and tooling systems, automatic and numerical control systems, higher mechanization
and greater output.
Introduction to Basic Manufacturing Processes and Workshop Technology
SCOPE OF STUDY
Today’s competitive manufacturing era of high industrial development and research, is being
called the age of mechanization, automation and computer integrated manufacturing. Due to
new researches in the manufacturing field, the advancement has come to this extent that
every different aspect of this technology has become a full-fledged fundamental and advanced
study in itself. This has led to introduction of optimized design and manufacturing of new
products. New developments in manufacturing areas are deciding to transfer more skill to the
machines for considerably reduction of manual labor. The scope of the subject of workshop
technology and manufacturing practices is a extremely wide as it specifies the need of greater
care for man, machine, material and other equipments involving higher initial investment by
using proper safety rule and precautions. The through and deep knowledge in the course of
study of this important subject is therefore becoming essential for all kinds of engineers to
have sound foundation in their profession. Therefore the course of study of this subject
provides a good theoretical background and a sound practical knowledge to the engineering
students and workshop staff. One should also be aware of the following terms for better
understanding of the scope of the study
Manufacturing is derived from the Latin word manufactus, means made by hand. In modern
context it involves making products from raw material by using various processes, by making
use of hand tools, machinery or even computers. It is therefore a study of the processes
required to make parts and to assemble them in machines. Process Engineering, in its
application to engineering industries, shows how the different problems related to development
of various machines may be solved by a study of physical, chemical and other laws governing
the manufacturing process. The study of manufacturing reveals those parameters which can
be most efficiently being influenced to increase production and raise its accuracy. Advance
manufacturing engineering involves the following concepts—
1. Process planning.
2. Process sheets.
3. Route sheets.
5. Cutting tools, machine tools (traditional, numerical control (NC), and computerized
numerical control (CNC).
6. Jigs and Fixtures.
7. Dies and Moulds.
8. Manufacturing Information Generation.
9. CNC part programs.
10. Robot programmers.
11. Flexible Manufacturing Systems (FMS), Group Technology (GT) and Computer
integrated manufacturing (CIM).
It is the process followed in a plant for converting semi- finished products or raw materials
into finished products or raw materials into finished products. The art of converting raw
material into finished goods with application of different types of tools, equipments, machine
tools, manufacturing set ups and manufacturing processes, is known as production. Generally
there are three basic types of production system that are given as under.
1. Job production
2. Batch production
3. Mass production
Job production comprises of an operator or group of operators to work upon a single job
and complete it before proceeding to the next similar or different job. The production
requirement in the job production system is extremely low. It requires fixed type of layout
for developing same products.
Manufacturing of products (less in number say 200 to 800) with variety of similar parts
with very little variation in size and shape is called batch production. Whenever the production
of batch is over, the same manufacturing facility is used for production of other batch product
or items. The batch may be for once or of periodical type or of repeated kinds after some
irregular interval. Such manufacturing concepts are leading to GT and FMS technology.
Manufacturing of products in this case requires process or functional layout.
Where as mass production involves production of large number of identical products (say
more than 50000) that needs line layout type of plant layout which is highly rigid type and
involves automation and huge amount of investment in special purpose machines to increase
Process planning consists of selection of means of production (machine-tools, cutting tools,
presses, jigs, fixtures, measuring tools etc.), establishing the efficient sequence of operation,
determination of changes in form, dimension or finish of the machine tools in addition to the
specification of the actions of the operator. It includes the calculation of the machining time,
as well as the required skill of the operator. It also establishes an efficient sequence of
manufacturing steps for minimizing material handling which ensures that the work will be
done at the minimum cost and at maximum productivity. The basic concepts of process
planning are generally concerned with the machining only. Although these concepts may also
be extended to other processes such as casting, forging, sheet metal forming, assembling and
heat treatment as well.
1.6 MANUFACTURING PROCESS
Manufacturing process is that part of the production process which is directly concerned
with the change of form or dimensions of the part being produced. It does not include the
transportation, handling or storage of parts, as they are not directly concerned with the
changes into the form or dimensions of the part produced.
CLASSIFICATION OF MANUFACTURING PROCESSES
For producing of products materials are needed. It is therefore important to know the
characteristics of the available engineering materials. Raw materials used manufacturing of
products, tools, machines and equipments in factories or industries are extracted from ores.
The ores are suitably converted the metal into a molten form by reducing or refining processes
4 Introduction to Basic Manufacturing Processes and Workshop Technology
in foundries. This molten metal is poured into moulds for providing commercial castings,
called ingots. Such ingots are then processed in rolling mills to obtain market form of
material supply in form of bloom, billets, slabs and rods. These forms of material supply are
further subjected to various manufacturing processes for getting usable metal products of
different shapes and sizes in various manufacturing shops. All these processes used in
manufacturing concern for changing the ingots into usable products may be classified into six
major groups as primary shaping processes, secondary machining processes, metal forming
processes, joining processes, surface finishing processes and processes effecting change in
properties. These are discussed as under.