Machining processes and types

1. 1

2. REVIEW OF TOPICS
• Fitting And Assembling
• Welding
• Forging
• Casting
• Machining Processes
• Gear Making
• Electric Circuits
• Electroplating
• Wood Working
• Workshop Safety2

3. JUST TO REMIND YOU ABOUT
EXAMS,QUIZES,ASSIGNMENT AND FINAL VIVA
• Your Two Sessional Exams (40 Marks each)will be held
during 6th and 12th week of Course
• Two Quiz tests (10 Marks each) will also held
• Assignments will also be given
• You are required to submit a Note Book (100 Marks)
before final viva
• Final Exam
• Final Viva and Project
• Warning: Min 75 % attendance is required to appear in
the Exam. Check and confirm your attendance
regularly from ERP System.

4. 4

5. Introduction
To
Machining

6. OBJECTIVE
1.Knowledge about various machining
processes and lathe machine components
2.Operational study of functions
performed by lathe

7. Machine Shop Safety Rules
• 1. Safety glasses, or appropriate goggles / face shields are
required in the shop, whether working or not!!
• 2. Shoes must be worn in any shop area. No one wearing
sandals will be allowed to enter any shop area. The
• minimum footwear must cover the entire foot.
• 3. Do not operate any item of equipment unless you are
familiar with its operation and have been authorized to
• operate it. If you have any questions regarding the use of
equipment ask the Shop Manager.
• 4. Avoid excessive use of compressed air to blow dirt or chips
from machinery to avoid scattering chips. Never
• use compressed air guns to clean clothing, hair, or aim at
another person.
• 5. In case of injury, no matter how slight, you must report it to
the Shop Manager.

8. Safety (Contd)
• 6.Do not attempt your self to remove foreign objects from
the eye or body. If chemicals get in the eye(s), wash eye(s)
for15 minutes in an open flow of water before proceeding
for medical treatment. Inform the Shop Manager
• 7. Machines must be shut off when cleaning, repairing, or
oiling.
• 8. Do not wear ties, loose clothing, long sleeves, jewelry,
gloves, etc. around moving or rotating machinery.
• 9.Long hair must be tied back or covered to keep it away
from moving machinery.
• 10.Hand protection in the form of suitable gloves should
be used for handling hot objects, glass or sharp-edged
items.

9. Safety (Contd)
• 11. Wear appropriate clothing for the job.
• 12. Do not work in the shop if tired, or in a hurry.
• 13.Practice cleanliness and orderliness in the
shop areas. Never leave a dirty piece of
equipment.
• 14. Keep the floor around machines clean, dry
and free from trip hazards. Do not allow chips to
accumulate.
• 15. Think through the entire job before starting.
Ask the Shop Manager if you are ever unsure for
any reason.

10. MACHINING
 Machining is a processes in which a piece of
raw material is cut into a desired final shape
and size by a controlled material-removal
process.

11. Assignment-1
Difference between Manufacturing & Fabrication

12. MACHINE TOOL
• A lathe is a machine tool which rotates the
work piece on its axis to perform various
operations such as cutting, sanding, knurling,
drilling, or deformation with tools that are
applied to the work piece to create an object
which has symmetry about an axis of
rotation.

13. 13

14. 14
Machining Processes
Include the following:
 Safety Equipment
 Metal removing process
 Unwanted material -- chips or swarfs
 Raw Work piece
 Machine Tool
 Machine Shop
 Machinist + ?

15. Material Removal Processes
A combination of shaping operations, the common feature of which
is removal of material from a work piece so the remaining part
acquires the desired shape
•Categories: Traditional and non traditional processes
Machining
– It’s a traditional material removal by a Mechanical Equipment and
sharp cutting tool, e.g., turning, milling, drilling
Abrasive processes
–material removal by hard, abrasive particles, e.g., grinding
,sand blasting
Non traditional processes
- Non traditional processes-various energy forms other than sharp
cutting tool to remove material, like chemicals ,laser water jet etc.

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Material Removal Processes(Contd)
Mechanical
 Single-point cutting
Turning
Planning and shaping
 Multi-point cutting
Milling
Drilling
Broaching
Sawing

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 Abrasive machining
Grinding
Honing
Lapping
Abrasive jet machining
Sand blasting
Material Removal Processes(Contd)

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Chemical
 Chemical machining
 Electrochemical machining (ECM)
Thermal
 Torch cutting
 Electrical discharge machining (EDM)
 High energy beam machining
Others
 Laser Cutting and CNC
 Water Jet Cutting
 Ultrasonic machining
Non Traditional Material Removal Processes

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Metal Cutting Processes

20. BREAK

21. Machining
• Machining is any of various processes in which a piece of
raw material is cut into a desired final shape and size by a
controlled material-removal process.
• It requires a mechanical equipment and a sharp cutting tool
to remove material
• Machining Cutting action involves shear deformation of work
material to form a chip
• As chip is removed, a new surface is exposed
• Figure 21.2 -(a) A cross-sectional view of the machining process, (b) tool with negative rake angle; compare with
positive rake angle in (a)

22. Machining in the Manufacturing
Sequence
•Generally performed after other manufacturing
processes, such as casting, forging, and bar
drawing –Other processes create the general
shape of the starting a work piece
• Machining provides the final shape,
dimensions, finish, and special geometric
details that other processes cannot create

23. Machining Operations
Some important machining operations:
• Turning
• Drilling Lathe machine
• Milling
Other machining operations:
• Shaping and planing
• Broaching and hobbing
• Sawing and engraving

24. Machining Operations(Contd)
Turning
Turning is a machining process in which a cutting
tool, typically a non-rotary tool bit, describes a
helical tool path by moving more or less linearly
while the work piece rotates. The tool's axes of
movement may be literally a straight line, or
they may be along some set of curves or angles,
but they are essentially linear.
• Taper Angle in taper turning = D-d/L * 144/5

25. Turning
Turning Single point cutting tool removes
material from a rotating work piece to form a
cylindrical shape

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Turning

27. Machining Operations (Contd)
Boring
• Boring is the process of enlarging a hole that has already been
drilled (or cast), by means of a single-point cutting tool.
Drilling
• Drilling is a cutting process that uses a drill bit to cut or enlarge a
hole of circular cross-section in solid materials. The drill bit is a
rotary cutting tool, often multipoint.
Broaching
• Broaching is a machining process that uses a toothed tool, called a
broach, to remove material. There are two main types of broaching:
linear and rotary.
Honning
• The honing process is used to obtain precise dimensions and
surfaces in cylindrical shapes

28. BORING

29. IDENTIFY THE PROCESS

30. Yes- Its a Boring Machine

31. TUNNEL BORING MACHINE AT NJ HPP

32. TBM

33. DRILLING

35. IDENTIFy THe PROCESs

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Tapping

37. Machining Operations (Contd)
Reaming
• The sizing operation that removes a small
amount of metal from a hole already drilled

38. Threading
• Taps and dies are used to create screw
threads, which is called threading. A tap is
used to cut the internal threads (e.g., a nut). A
die is used to cut the external threads (e.g., a
bolt). Threading can also be done through
Lathe.

39. Grooving
• A process in which a long and narrow
indentation built into a material, generally for
the purpose of allowing another material or
part to move within the groove and be guided
by it.

40. Machining Operations (Contd)
Facing (decrease length)
• It involves moving the cutting tool at right angles to
the axis of rotation of the rotating work piece.

41. Parting
• This process is used to create deep grooves
which will remove a completed or part-
complete component from its parent stock.

42. Working on Lathe

43. Knurling
• The cutting of a serrated pattern onto the
surface of a part to use as a hand grip using a
special purpose knurling tool.

44. Engraving
It is a machining operation by which different figures
are engraved on a machined surface.

45. Hobbing
Hobbing is a machining process for gear cutting,
cutting splines, and cutting sprockets on
a hobbing machine, which is a special type of
milling machine

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Hobbing Tool and Hobbing Machine

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Honing Operation
Honing Tools

49. Honing Operation

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Reamer
Tapered ReamerNo. 3 morse taper reamer

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Broaching Process

52. 52
Typical Internal Broach

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Grinding Process

54. Milling
• Milling Rotating multiple-cutting-edge tool is
moved slowly relative to work to generate
plane or straight surface
•Two forms: peripheral milling and face milling

55. EXERCISE

56. EXERCISE

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Chip Formation

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Types of Chips

59. Four Basic Types of Chip in Machining
1.Discontinuous chip
2.Continuous chip
3.Continuous chip with Built-up Edge (BUE)
4.Serrated chip

60. Segmented Chip
•Brittle work materials (e.g., cast irons)
•Low cutting speeds
•Large feed and
depth of cut
•High tool-chip friction

61. Continuous Chip
•Ductile work materials (e.g., low carbon steel)
•High cutting speeds
•Small feeds and depths
•Sharp cutting edge on
the tool the tool
•Low tool-chip friction

62. Continuous with BUE
•Ductile materials
•Low-to-medium cutting speeds
•Tool-chip friction causes
portions of chip to adhere
to rake face to rake face
•BUE formation is cyclical
; it forms, then breaks off

63. Serrated Chip
•Semi continuous -saw-
tooth appearance
•Cyclical chip formation
of alternating high shear
strain then low shear strain
•Most closely associated
with difficult-to-
•Most closely associated
with difficult-to- machine
metals at high cutting speeds

64. WAKE UP FOR A BREAK

66. BREAK