This document discusses various metal forming processes including hot working, cold working, rolling, forging, extrusion, and drawing. It provides details on: - Hot working above the recrystallization temperature improves properties while cold working below requires higher pressure - Rolling involves passing metal between rolls to change dimensions - Forging uses compressive forces to shape heated metal in dies - Extrusion forces metal through a die opening to form a continuous cross-section - Drawing reduces the cross-section of bars or rods by pulling them through successive dies

1. Sanjivani Rural Education Society’s
Sanjivani College of Engineering, Kopargaon-423 603
(An Autonomous Institute, Affiliated to Savitribai Phule Pune University, Pune)
NAAC ‘A’ Grade Accredited, ISO 9001:2015 Certified
Department of Mechanical Engineering
Gujrathi Sonam
Assistant Professor
Sanjivani College of Engineering, Kopargaon
E-mail : gujrathisonammech@sanjivani.org.in
Contact No: 8483874906
Subject :- Manufacturing Process I (MP I)
S.Y. B.Tech. Mechanical
Unit 3- Metal Forming Process

2. Contents
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon
Hot and Cold Working
Rolling
Forging
Extrusion
Drawing

3. Introduction
• Subsequent to casting further shaping operations are required either to produce
new shape or to improve the properties of the metal
• Non cutting shaping or non chipping shaping such as forging, rolling, pressing etc.
• Non cutting shaping are considered as mechanical working processes
• It a simple plastic deformation performed to change dimensions, properties and
surface condition by mechanical pressure
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

4. Hot and Cold working Process
• Hot working is the initial step of most metals and alloys
• Hot working combines the working and annealing processes by deforming
metal above the recrystallization temperature at which new grains are formed
• Since most metals have high recrystallization temperature they must worked at
high temperature
• The changes in structure from hot working improve mechanical properties such
as ductility, toughness, elongation percentage, reduction of area percentage ad
resistance to shock and vibration (advantages)
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

5. Methods of hot working
• Rolling
• Piercing
• Drawing
• Spinning
• Extrusion
• Forging etc.
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

6. Hot Rolling
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

7. Hot Rolling
• In deforming metal between rolls, the work subjected to high
compressive stresses form the squeezing action of rolls
• In this process, metal in a hot plastic state is passed between two rolls
revolving at the same speed but in opposite direction
• Disadvantages –
• Due to high working temperature rapid oxidation and scale formation takes
place
• Close tolerances can’t be obtained
• Excessive expenditure on high tooling cost
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

8. Cold working
• Below recrystallization temperature
• It requires higher pressure than hot working
• It doesn’t provide an appreciable reduction in size
• If the material is more ductile, it can be more cold worked
• Advantages
• Better dimensional control is possible
• Surface finish of the component is better
• Strength and hardness of metal are increased
• It is an ideal method for increasing hardness of those metals which do not respond to
the heat treatment
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

9. Cold working
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

10. Cold working
• Disadvantages
• Ductility of the material is decreased during process
• Only ductile metals can be shaped through cold working
• Over working of metals results in brittleness and it has to be annealed to
remove this brittleness
• Residual stresses are set up during the process
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

11. Methods of cold working
• Cold rolling
• Cold drawing
• Cold spinning
• Stretch forming
• cold extrusion
• Coining
• Embossing
• Cold bending
• Roll forming
• Shot peening etc.
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

12. Assignment No. 1
• Difference between hot and cold working Process
• What is warm working temperature
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

13. Assignment No 2
• Friction and lubrication is metal forming (theory)
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

14. Rolling
• Basic definitions
• Ingot – large c/s of suitable shape made for further processing
• Bloom – square or rectangular piece formed after reducing ingots e.g.
structural shapes, rails
• Billets – have smaller c/s than bloom e.eg. Plates, sheets, coils
• Slabs – rectangular c/s e.g. bars, rods etc.
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

15. rolling
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

16. Types of rolling mill
• Two high
• Three high
• Four high
• Cluster
• Tandem
• Planetary
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

17. Types of rolling mill
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

18. Assignment no. 3
• Write materials used for making of rollers as per application
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

19. Forging
• It is the process of shaping heated metal by the application of sudden
blows (hammer forging) or steady pressure (press forging) and makes
use of plasticity of the material
• May be done by hand or forging
• Used in mass production
• In hand forging hammering is done by hand
• E.g. engine crankshaft, connecting rods, gears, jet engines, turbine
parts, aircraft structure component etc
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

20. Classification of forging
• Hot forging
• Cold forging
• Impact forging
• Gradual pressure forging
• Open die forging
• Closed die forging/ impression die forging
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

21. Open and closed die forging
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

22. Open die forging operations
• Fullering
• Edging
• cogging
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

23. Assignment no 4
• Comparison between open die and closed die forging
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

24. Machine or upset forging
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

25. Roll forging
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon
Application
Knife blades, automobile drive shaft,
Shafts, axles, leaf springs

26. Extrusion
• Compression process in which the work metal is forced to flow
through small opening called die to produce required crossectional
shape
• Similar to squeezing toothpaste or cream from a tube
• Any solid and hollow c/s can be made out of extrusion
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

27. Classification extrusion
• Direct (forward) extrusion
• Indirect (backward) extrusion
• Hot extrusion
• Cold extrusion
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

28. Direct extrusion
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

29. Indirect extrusion
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

30. Assignment no 5
• Difference between direct and indirect extrusion
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

31. Extrusion dies
• Dies plays imp role in
process
• Important parameters
which can affect the
process are die angle
and die opening
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

32. Drawing
• c/s of bar, rod or wire is reduced by pulling it through a die opening
• In drawing the w/p is pulled through the die whereas in extrusion is
pushed through a die
• During this process tensile or compressive stresses are produced in
the material
• Depending upon the material to be drawn and the amount of
reduction required, total drawing is can be accomplished in a single
die or in a series of successive dies.
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

33. Drawing
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

34. Tube drawing
• Initial part of tubing is produced by extrusion, drawing to reduce
diameter or wall thickness of seamless tubes and pipes
• Tube drawing can be carried out with or without mandrel
• Mandrel not used method is called as tube sinking
• In tube sinking method no control over inner thickness and wall
thickness of tube
• To overcome this mandrel is used
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

35. Tube drawing
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon

36. Thank you
Gujrathi S.M. Department Of Mechanical Engineering, Sanjivani COE, Kopargaon