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 

Primary Shaping Processes

Primary shaping processes are manufacturing of
a product from an amorphous material. Some processes produces finish products
or articles into its usual form whereas others do not, and require further
working to finish component to the desired shape and size. Castings need
re-melting of scrap and defective ingots in cupola or in some other melting
furnace and then pouring of the molten metal into sand or metallic moulds to
obtain the castings. Thus the intricate shapes can be manufactured. Typical
examples of the products that are produced by casting process are machine beds,
automobile engines, carburetors, flywheels etc. The parts produced through
these processes may or may not require to under go further operations. Some of
the important primary shaping processes is:
(1)   Casting, (2) Powder
metallurgy, (3) Plastic technology, (4) Gas cutting, (5) Bending and (6) Forging.

Secondary or Machining Processes

As large number of components require further
processing after the primary processes. These components are subjected to one
or more number of machining operations in machine shops, to obtain the desired shape and dimensional accuracy on
flat and cylindrical jobs. Thus, the jobs
undergoing these operations are the roughly finished products received through
primary shaping processes. The process of removing the undesired or unwanted
material from the workpiece or job or
component to produce a required shape using a cutting tool is known as
machining. This can be done by a manual process or by using a machine called
machine tool (traditional machines namely
lathe, milling machine, drilling, shaper, planner, slotter).
In many cases these operations are performed on rods, bars and flat surfaces in
machine shops. These secondary processes are mainly
required for achieving
dimensional accuracy and a very high degree of surface finish. The
secondary processes require the use of one or more  machine tools, various
single or multi-point cutting tools (cutters), job holding devices,
marking and measuring instruments, testing devices and gauges etc. for
getting desired dimensional control and required
degree of surface
finish on the workpieces. The example of parts produced by machining processes includes
hand tools machine tools instruments, automobile parts, nuts, bolts and gears etc. Lot of material is wasted as
scrap in the secondary or machining process.