The document discusses various metal forming processes used to change the shape of metal workpieces through plastic deformation exceeding the metal's yield strength, including bulk deformation techniques like rolling, forging, and extrusion that involve significant shape changes with lower surface area to volume ratios, and sheet metalworking techniques like bending, drawing, and shearing that are performed on metal sheets or strips with higher surface area to volume ratios. Metal forming is an important manufacturing method that allows for net or near-net shape production, high production rates, profitability, and improved material properties.

1. Fundamentals of Metal Forming
Processes
Prepared by
Prof. Naman M. Dave
Assistant Professor,
Mechanical Engg. Dept.
Gandhinagar Institute of Technology

2. 2
Shaping: usually involves
molding and casting.
Ex. The white ceramic
insulator for a spark plug of a
car body for a car (clay
molding, drying and firing)
Forming and Shaping
Forming: means changing the
shape of an existing solid
body.
Ex. The metal body for a car
(sheet metal forming)

3. 3
Metal Forming Processes
• Metal Forming includes a large group of
manufacturing processes in which plastic
deformation is used to change the shape of metal
work-pieces.
• Deformation results from the use of a tool, usually a
die in metal forming, which applies stresses that
exceed the yield strength of the metal.

4. 4
Hammer forging two connecting rods; (a) bar stock;
after (b) fullering, (c) “rolling”, (d) blocking, (e) finishing,
(f) trimming; (g) the flash; (h) the forging dies.
(a) (b) (c) (d) (e) (f) (g) (h)

5. 5
Bulk Deformation:
 Compressive deformation force.
 Significant deformations.
 Massive shape changes.
 Starting work shapes include billets
and rectangular bars.
 Surface area / volume is small.
Metal Forming Processes
Sheet Metal-working:
 Also called “Press-working”.
 Cold working processes.
 Use set of punch and die.
 Performed on metal sheets, strips
and coils.
 Surface area / volume is large.

6. 6
Surface
Area /
Volume
is large
Bending
operations
Shearing
processes
Deep or Cup
drawing
Sheet
Metalworking
Surface
Area /
Volume
is small
Rolling
Forging
Extrusion
Wire and Bar
drawing
Bulk
Deformation
Metal Forming Processes

7. 7
Rolling: A compressive deformation process in which the
thickness of slab or plate is reduced by two opposing
tools “rolls”. They rotate to draw the work piece into the
gap between them and squeeze it.
Bulk DeformationProcesses

8. 8
Forging: The work-piece is compressed between two
opposing dies so that the die shapes are imparted to work.
It is traditionally hot working process however many types
of forging are performed cold.
Bulk DeformationProcesses

9. 9
Extrusion: A compressive deformation process in which
the work metal is forced to flow through a die opening to
produce a desired cross-sectional shape.
Bulk DeformationProcesses

10. 10
Drawing: The work metal is being pulled through a die
opening to reduce the diameter of a wire or a bar. See Fig.
Wire Drawing.
Bulk DeformationProcesses

11. Examples of Precision
Cold Forged Products
11

12. Precision Hot Forging of Complex
Shapes
12

13. Precision Hot Forging of Complex
Shapes
13

14. 14
Bending: It involves straining of metal sheet or plate to take
an angle along a (usually) straight axis.
Sheet MetalworkingProcesses

15. 15
Drawing: (Cup or deep drawing) Forming of a flat metal
sheet into a hollow or concave shape, such as cup, by
stretching the metal. A blank holder is used to hold down
the blank while the punch pushes into the sheet metal.
Sheet MetalworkingProcesses

16. 16

17. 17
Shearing: It involves cutting rather than forming of a
metal. A shearing operation cuts the work using a punch
and die.
Sheet MetalworkingProcesses

18. Importance of Metal Forming in
Manufacturing Engineering
• Net Shape or Close to Net Shape
• High Production Rate
• High Profit Margin
• Low Scrap Rate
• Improving Material Properties
18

19. Applications and Products of Metal
forming in Macro Scale
• Automotive
• Aerospace
• Appliance
• Cookware
19

20. Current Issues of Metal Forming Industry
• Lack of Experienced Metal Forming Engineer
• Short Product Life Cycle
• New Metallic Materials
• Developing New Hybrid Process
• High Accuracy and Small Feature Products
20

21. Skills Needed for Metal Forming
Engineering
• Mechanics
• Material Science
• Manufacturing Process
• Design and Control
• Machinery
• Computer Skills
• FEA
21

22. Students Need
• To know the current and future needs of
metal forming industry.
• To be taught on a series of classes to meet
challenges of current and future metal
forming industry.
22

23. Homework
• Is metal forming the most cost effective
manufacturing process?
• Why metal forming is the best process for
mass production?
• According to your imagination, what is the
best process to make beverage can?
23