1. Sheet-Metal Forming

2. Introduction
Sheet metal forming is a process that materials undergo permanent deformation by cold forming to produce a variety of complex three dimensional shapes.
The process is carried out in the plane of sheet by tensile forces with high ratio of surface area to thickness.
Friction conditions at the tool-metal interface are very important and controlled by press conditions, lubrication, tool material and surface condition, and strip surface condition.

3. Classification of sheet metal parts (based on contour)
1) Singly curved parts 2) Contoured flanged parts, i.e., parts with stretch flanges and shrink flanges. 3) Curved sections. 4) Deep-recessed parts, i.e., cups and boxes with either vertical or sloping walls. 5) Shallow-recessed parts, i.e., dish-shaped, beaded, embossed and corrugated parts.

4. Classification of sheet metal forming (based on operations)
Shearing
Blanking
Punching
Bending
Stamping
Deep drawing
Embossing
Spinning
Roll Forming

5. Forming machines Press
A press is a machine used for performing most of the cold working operations.
Rigid Machine Frame
Press Tools
Ram
Power Source and Mechanism
Die Assy
Press Accessories

6. Types of Press Source of Power Manual Press Mechanical Press
Hydraulic Press
Pneumatic Press

7. Mechanical presses
energy stored in a flywheel is transferred to the movable slide on the down stroke of the press.
quick - acting , short stroke.
Hydraulic presses
slower - acting, longer stroke.

8. 2.Actions of presses
According to number of slides, which can be operated independently of each other. 1) Single - action press - one slide - vertical direction 2) Double - action press - two slides - the second action is used to operated the hold-down, which prevents wrinkling in deep drawing. 3) Triple - action press - two actions above the die, one action below

9. 3. Method of transmitting power to ram
Crank shaft and connecting rod system
Cam
Eccentric
Toggle joint
Knuckle joint
Rack and Pinion
Screw
Gears

11. 4. Position of the Ram Vertical Inclined 5. Use
Blanking press, embossing press, Drawing press etc.

12. 6. Design of Frame
7. Capacity or Size

13. Die Assembly Die Block Die retainer & Die shoe Stripper Punch
Punch retainer & Punch pad
Pressure Plate
Punch Holder
Guide Pillars
Stock Guide

14. Classification of Die Single Operation Die Multi Operation Die
Cutting Die
Forming Die
Multi Operation Die
Compound Die
Progressive Die
Transfer Die

15. Single Operation Die
Cutting Die
Forming Die

16. Single Operation Die

17. Multi Operation Die
Compound Die

18. Multi Operation Die Progressive Die
Punches and dies are designed so that successive stages in the forming of the part are carried out in the same die on each stroke of the press.
The strip is fed from left to right.
The first punch is to make the hole of the washer.
The washer is then blanked from the strip.
The punch A is piercing the hole for the next washer.

19. Theory of Shearing the Metal

20. Theory of Shearing the Metal

21. Theory of Shearing the Metal

22. Effect of Clearence

23. Bending Process

24. Bending Process
A process by which a straight length is transformed into a curved length.
Produce channels, drums, tanks.

25. Bending Operation
V-Die Bending

26. Punch Press Bends

27. Roll Forming

28. Roll Bending

29. Bending in sliding die machines

30. Press Brake Forming A single action press with a very long narrow bed.
• Used to form long, straight bends in pieces such as channels and corrugated sheets.

31. Press Brake Forming A single action press with a very long narrow bed.
• Used to form long, straight bends in pieces such as channels and corrugated sheets.

32. Beading

33. Method of Bending
Three-roll bender:
Wiper-type bender:
Wrap forming:

34. Wiper-type bender:

35. Definition of terms used in bending

37. Spring Back
Springback - the elastic recovery of the material after unloading of the tools
To compensate with the unbending action of the springback, the metal should be slightly overbent.

40. Rubber Forming

44. Types of Stretch Forming

54. Shaving can be used to produce a smoother edge
finishing operation in which a small amount of metal is sheared away from the edge of an already blanked part
can be used to produce a smoother edge

55. Trimming